System and method for charging a battery (capacitor) of a playback device

Abstract

A system and method for charging a battery of an audio playback device are disclosed. An exemplary method executed by a media playback system includes receiving power from a first power source and charging a first capacitor of a first playback device according to a first charging method, and receiving power from a second power source and charging a second capacitor of a second playback device according to a second charging method. The system receives an instruction to form a group for synchronous audio playback and obtains one or more power parameters associated with the first playback device and / or the second playback device. After receiving the instruction to form a group, the system modifies the first charging method based on the one or more power parameters and receives power from the first power source to charge the first capacitor according to the modified first charging method.

Description

[Technical Field]

[0001] This international application claims the benefit of U.S. Provisional Patent Application No. 63 / 367,006, filed June 24, 2022, which is incorporated herein by reference in its entirety. The present disclosure relates to consumer products, and more particularly to methods, systems, products, features, services, and other elements directed to media playback, or some aspects thereof. [Background technology]

[0002] Options for accessing and listening to digital audio in out-of-home settings were limited until 2002, when Sonos, Inc. began developing a new type of playback system. Sonos filed one of its first patent applications in 2003, titled "Method for Synchronizing Audio Playback between Multiple Networked Devices," and began selling its first media playback system in 2005. The Sonos Wireless Home Sound System allows people to experience music from many sources through one or more networked playback devices. Through a software control application installed on a controller (e.g., smartphone, tablet, computer, audio input device), people can play desired music in any room equipped with a networked playback device. Media content (e.g., songs, podcasts, video sounds) is streamed to the playback device, allowing different corresponding media content to be played in each room equipped with a playback device. Multiple rooms can also be grouped for synchronized playback of the same media content and / or the same media content can be listened to in all rooms simultaneously.

[0003] The features, aspects, and advantages of the technology disclosed herein may be better understood with reference to the following description, the appended claims, and the accompanying drawings, as set forth below. Those skilled in the art will appreciate that the features shown in the drawings are for illustrative purposes and that variations, including different and / or additional features and arrangements thereof, are possible. [Brief explanation of the drawings]

[0004] [Figure 1A] 1 is a partial cross-sectional view of an environment including a media playback system configured in accordance with aspects of the disclosed technology. [Figure 1B] 1B is a schematic diagram of the media playback system and one or more networks of FIG. 1A. [Figure 1C] FIG. 2 is a block diagram of a playback device. [Figure 1D] FIG. 2 is a block diagram of a playback device. [Figure 1E] FIG. 1 is a block diagram of a network microphone device. [Figure 1F] FIG. 1 is a block diagram of a network microphone device. [Figure 1G] FIG. 2 is a block diagram of a playback device. [Figure 1H] FIG. 2 is a schematic partial view of a control device. [Figure 1I] 1 is a schematic diagram of a corresponding media playback system zone. [Figure 1J] 1 is a schematic diagram of a corresponding media playback system zone. [Figure 1K] 1 is a schematic diagram of a corresponding media playback system zone. [Figure 1L] 1 is a schematic diagram of a corresponding media playback system zone. [Figure 1M] FIG. 1 is a schematic diagram of a media playback system area. [Figure 2A] FIG. 1 is a front isometric view of a playback device configured in accordance with aspects of the disclosed technology. [Figure 2B] FIG. 2B is a front isometric view of the playback device of FIG. 2A without the grill. [Figure 2C] FIG. 2B is an exploded view of the playback device of FIG. 2A. [Figure 2D] FIG. 10 is a schematic diagram of another example of a housing for a playback device. [Figure 2E] FIG. 10 is a schematic diagram of another example of a housing for a playback device. [Figure 3A] FIG. 1 is a front view of a network microphone device configured in accordance with aspects of the disclosed technology. [Figure 3B] FIG. 3B is a side isometric view of the network microphone device of FIG. 3A. [Figure 3C] FIG. 3C is an exploded view of the network microphone device of FIGS. 3A and 3B. [Figure 3D] FIG. 3C is an enlarged view of a portion of FIG. 3B. [Figure 3E] FIG. 3D is a block diagram of the network microphone device of FIGS. 3A to 3D. [Figure 3F] FIG. 2 is a schematic diagram of an exemplary voice input. [Figure 4A] 1A-1C are schematic diagrams of a control device at various stages of operation in accordance with aspects of the disclosed technology; [Figure 4B] 1A-1C are schematic diagrams of a control device at various stages of operation in accordance with aspects of the disclosed technology; [Figure 4C] 1A-1C are schematic diagrams of a control device at various stages of operation in accordance with aspects of the disclosed technology; [Figure 4D] 1A-1C are schematic diagrams of a control device at various stages of operation in accordance with aspects of the disclosed technology; [Figure 5] FIG. 2 is a front view of the control device. [Figure 6] FIG. 2 is a message flow diagram for a media playback system. [Figure 7] 1 is a block diagram illustrating a configuration of an exemplary wireless power supply device according to an aspect of the present technology. [Figure 8] FIG. 1 is a block diagram illustrating an example wireless power group configuration, in accordance with aspects of the present technique. [Figure 9]1 is a flowchart illustrating an exemplary method for updating a charging scheme for one or more playback devices, in accordance with aspects of the present technology. [Figure 10] 1 is a flowchart illustrating an exemplary method for cycling through devices in a media playback system, in accordance with aspects of the present technique. [Figure 11] 1 is a flowchart illustrating an exemplary method for shifting device responsibility in a media playback system, in accordance with aspects of the present technique. [Figure 12A] 1 is a schematic diagram illustrating an example of a device charging scheme in accordance with aspects of the present technology. [Figure 12B] 1 is a schematic diagram illustrating an example of a device charging scheme in accordance with aspects of the present technology. [Figure 12C] 1 is a schematic diagram illustrating an example of a device charging scheme in accordance with aspects of the present technology. [Figure 12D] 1 is a schematic diagram illustrating an example of a device charging scheme in accordance with aspects of the present technology. [Figure 13A] FIG. 1 is a schematic diagram illustrating an example of a device playback session in accordance with aspects of the present technology. [Figure 13B] FIG. 1 is a schematic diagram illustrating an example of a device playback session in accordance with aspects of the present technology. [Figure 13C] FIG. 1 is a schematic diagram illustrating an example of a device playback session in accordance with aspects of the present technology. [Figure 14A] 1A-1C are schematic diagrams illustrating example device charging schemes and / or media data transmissions in accordance with aspects of the present technology. [Figure 14B] 1A-1C are schematic diagrams illustrating example device charging schemes and / or media data transmissions in accordance with aspects of the present technology. [Figure 14C] 1A-1C are schematic diagrams illustrating example device charging schemes and / or media data transmissions in accordance with aspects of the present technology.

[0005] The drawings are intended to illustrate some exemplary embodiments, but it will be understood by those skilled in the art that the technology disclosed herein is not limited to the arrangements and instrumentality shown in the drawings. DETAILED DESCRIPTION OF THE INVENTION

[0006] I. Overview In conventional media playback systems, one or more playback devices, such as playback device 110 (FIG. 1A), often include one or more rechargeable capacitors or batteries. The use of such rechargeable batteries allows users to use and reuse their devices without having to purchase new batteries to replace dead ones. Furthermore, these playback devices often use standardized charging ports and connector types (e.g., USB-A, USB-B, USB-C, APPLE LIGHTNING®), allowing charging and recharging without specialized cables or hardware, enhancing the portability and ease of use of the playback devices. In conventional charging schemes, batteries in such playback devices are charged to their full capacity at or near the maximum charge rate allowed by the device or the underlying hardware of the charging system, without consideration of charging conditions or needs. However, batteries made with certain chemistries (e.g., lithium ion, lithium polymer, nickel metal hydride) can rapidly degrade in performance and capacity depending on the charging conditions. For example, charging a lithium ion battery to 100% is typically discouraged due to the current and / or voltage required to continue charging beyond a certain threshold (e.g., 95% capacity). Conversely, charging lithium-ion batteries using a lower charging rate (e.g., 0.5C, 0.7C, etc.) rather than a higher charging rate (e.g., 1.5C, 2C, etc.) can significantly extend battery life. In some cases, playback devices can be combined to create a group for synchronous playback of media content. However, these devices may have different charging capacities, charging rates, discharge rates, playback responsibilities, etc. Therefore, these playback devices may run out of power or charge at different times during synchronous playback, resulting in problems such as reduced performance of the entire media playback system and reduced user enjoyment.

[0007] The disclosed playback devices, media playback systems, and / or methods can improve battery performance and battery age or lifespan by employing a charging profile or scheme based on the device state, device operating parameters, device usage patterns, device harvesting schedules / occasions, etc., of one or more playback devices. Furthermore, playback devices can utilize playback device group dynamics to offload or share responsibilities among playback devices in a group or among playback devices in a group to extend the battery life of one or more devices. The disclosed media playback systems employ different charging schemes for playback devices to reduce battery degradation and maintain or extend battery life. By permitting batteries to be charged according to a dynamic charging scheme configured to reduce battery degradation and extend battery life, the usability of the media playback system to one or more users is improved compared to conventional approaches.

[0008] Although some examples described herein may refer to functions performed by certain actors, such as "users," "listeners," and / or other entities, it should be understood that this is for illustrative purposes only. The claims should not be construed as requiring action by such example actors unless expressly required by the language of the claims themselves.

[0009] In the figures, identical reference numbers identify generally similar and / or identical elements. To facilitate the description of any particular element, the most significant digit or digits of the reference number refer to the figure in which that element is first introduced. For example, element 110a is first introduced and described with reference to FIG. 1A. Many of the details, dimensions, angles, and other features shown in the figures are merely illustrative of particular embodiments of the disclosed technology. Thus, other embodiments can have other details, dimensions, angles, and features without departing from the spirit or scope of the present disclosure. Moreover, those skilled in the art will appreciate that additional embodiments of the various disclosed technologies can be practiced without some of the details described below.

[0010] II. Optimal Operating Environment 1A is a partial cross-sectional view of a media playback system 100 disposed in an environment 101 (e.g., a home). The media playback system 100 includes one or more playback devices 110 (individually identified as playback devices 110a-n), one or more network microphone devices (“NMDs”) 120 (individually identified as NMDs 120a-c), and one or more control devices 130 (individually identified as control devices 130a, 130b).

[0011] As used herein, the term "playback device" can generally refer to a network device configured to receive, process, and output data for a media playback system. For example, a playback device can be a network device configured to receive and process audio content. In some embodiments, a playback device includes one or more transducers or speakers powered by one or more amplifiers. However, in other embodiments, a playback device includes either a speaker and an amplifier (or neither). For example, a playback device can include one or more amplifiers configured to drive one or more speakers external to the playback device via corresponding wires or cables.

[0012] Additionally, as used herein, the term NMD (i.e., "network microphone device") may generally refer to a network device configured for audio detection. In some embodiments, the NMD is a standalone device configured primarily for audio detection. In other embodiments, the NMD is integrated into a playback device (or vice versa).

[0013] The term "control device" may generally refer to a network device configured to perform related functions to facilitate user access, control, and / or configuration of media playback system 100.

[0014] Each of the playback devices 110 is configured to receive audio signals or data from one or more media sources (e.g., one or more remote servers, one or more local devices) and play the received audio signals or data as sound. One or more NMDs 120 are configured to receive spoken word commands, and one or more control devices 130 are configured to receive user input. In response to the received spoken word commands and / or user input, the media playback system 100 can play audio via one or more of the playback devices 110. In certain embodiments, the playback devices 110 are configured to initiate playback of media content in response to a trigger. For example, one or more of the playback devices 110 may be configured to play a morning playlist when an associated trigger condition (e.g., a user's presence in the kitchen, detection of operation of a coffee machine) is detected. In some embodiments, for example, the media playback system 100 is configured to play audio from a first playback device (e.g., playback device 100a) in synchronization with a second playback device (e.g., playback device 100b). Interactions between playback device 110, NMD 120, and / or control device 130 of media playback system 100 configured according to various embodiments of the present disclosure are described in more detail below with respect to FIGS. 1B-1L.

[0015] 1A , environment 101 comprises a home with multiple rooms, spaces, and / or playback zones, including (clockwise from top left) master bathroom 101a, master bedroom 101b, second bedroom 101c, family room or den 101d, office 101e, living room 101f, dining room 101g, kitchen 101h, and outdoor patio 101i. While specific embodiments and examples are described below in the context of a home environment, the techniques described herein may be implemented in other types of environments. In some embodiments, for example, media playback system 100 may be implemented in one or more commercial facilities (e.g., restaurants, malls, airports, hotels, retail stores, or other businesses), one or more vehicles (e.g., sport utility vehicles, buses, automobiles, ships, boats, airplanes), multiple environments (e.g., a combination of home and vehicle environments), and / or another suitable environment where multi-zone audio may be desirable.

[0016] Media playback system 100 can be configured with one or more playback zones, some of which may correspond to rooms within environment 101. Media playback system 100 may be established with one or more playback zones, after which additional zones may be added or removed to establish, for example, the configuration shown in FIG. 1A. Each zone may be named according to a different room or space, such as office 101e, master bathroom 101a, master bedroom 101b, second bedroom 101c, kitchen 101h, dining room 101g, living room 101f, and / or patio 101i. In some embodiments, a single playback zone may include multiple rooms or spaces. In certain embodiments, a single room or space may include multiple playback zones.

[0017] In the illustrated embodiment of FIG. 1A , master bathroom 101a, second bedroom 101c, office 101e, living room 101f, dining room 101g, kitchen 101h, and outdoor patio 101i each include one playback device 110, while master bedroom 101b and den 101d include multiple playback devices 110. In master bedroom 101b, playback devices 110l and 110m may be configured to synchronously play audio content, e.g., as individual ones of multiple playback devices 110, as combined playback zones, as integrated playback devices, and / or any combination thereof. Similarly, in den 101d, playback devices 110h-j may be configured to synchronously play audio content, e.g., as individual ones of multiple playback devices 110, as one or more combined playback devices, and / or as one or more integrated playback devices. Additional details regarding combined playback devices and integrated playback devices are described below, e.g., with respect to FIGS. 1B and 1E and 1I-1M.

[0018] In some embodiments, one or more playback zones in environment 101 may each play different audio content. For example, one user may be grilling on patio 101i and listening to hip hop music played by playback device 110c, while another user is preparing food in kitchen 101h and listening to classical music played by playback device 110b. In another example, a playback zone may play the same audio content in synchronization with another playback zone. For example, a user may be in office 101e and hear the same hip hop music being played by playback device 110f on patio 101i as that being played by playback device 110c. In some embodiments, playback devices 110c and 110f play hip hop music in synchronization so that the user perceives that the audio content is being played seamlessly (or at least substantially seamlessly) while moving between different playback zones. Additional details regarding audio playback between playback devices and / or playback zones can be found, for example, in U.S. Pat. No. 8,234,395, entitled "System and method for synchronizing operations among a plurality of independently clocked digital data processing devices," which is incorporated herein by reference in its entirety.

[0019] To facilitate synchronized playback, the playback device(s) described herein, in some embodiments, are configurable to operate in (and / or switch between) different modes, such as an audio playback group coordinator mode and / or an audio playback group member mode. While operating in the audio playback group coordinator mode, the playback device is configured to coordinate playback within the group, for example, by performing one or more of the following functions: (i) receiving audio content from an audio source; (ii) generating playback timing information for the audio content using a clock (e.g., a physical clock or a virtual clock) within the playback device; (iii) transmitting portions of the audio content and playback timing for the portions of the audio content to at least one other playback device (e.g., at least one other playback device operating in audio playback group member mode); (iv) transmitting timing information (e.g., generated using the clock) to at least one other playback device; and / or (v) playing the audio content synchronously with at least one other playback device using the generated playback timing information and / or clock. While operating in the audio playback group member mode, the playback device is configured to perform one or more of the following functions: (i) receiving audio content and playback timing of the audio content from at least one other device (e.g., a playback device operating in the audio playback group coordinator mode); (ii) receiving timing information from at least one other device (e.g., a playback device operating in the audio playback group coordinator mode), and / or (iii) using the playback timing and / or timing information of the audio content to play the audio content in synchronization with at least the other playback devices.

[0020] a. Preferred Media Playback System 1B is a schematic diagram of a media playback system 100 and a cloud network 102. For ease of illustration, certain devices of the media playback system 100 and the cloud network 102 are omitted from FIG. 1B. One or more communication links 103 (hereinafter "links 103") are provided to communicatively couple the media playback system 100 and the cloud network 102.

[0021] Link 103 may comprise, for example, one or more wired networks, one or more wireless networks, one or more wide area networks (WANs) (e.g., the Internet), one or more local area networks (LANs) (e.g., WIFI networks), one or more personal area networks (PANs) (e.g., one or more BLUETOOTH networks, Z-WAVE networks, wireless universal serial bus (USB) networks, ZIGBEE networks, and / or IRDA networks), one or more communications networks (e.g., one or more Global System For Mobiles (GSM) networks, Code Division Multiple Access (CDMA) networks, Long-Term Evolution (LTE) networks, 5G communications networks, and / or other suitable data transmission protocol networks), etc. Cloud network 102 is configured to deliver media content (e.g., audio content, video content, photos, social media content) to media playback system 100 in response to requests sent from media playback system 100 via link 103. In some embodiments, cloud network 102 is further configured to receive data (e.g., voice input data) from media playback system 100 and, in response, send commands and / or media content to media playback system 100.

[0022] Cloud network 102 comprises computing devices 106 (individually identified as first computing device 106a, second computing device 106b, and third computing device 106c). Computing devices 106 may comprise individual computers or servers, such as media streaming service servers that store audio and / or other media content, voice service servers, social media servers, media playback system control servers, etc. In some embodiments, one or more of computing devices 106 comprise modules of a single computer or server. In particular embodiments, one or more of computing devices 106 comprise one or more modules, computers, and / or servers. Furthermore, while cloud network 102 is described above in the context of a single cloud network, in some embodiments, cloud network 102 comprises multiple cloud networks comprising communicatively connected computing devices. Furthermore, while in FIG. 1B cloud network 102 is shown as having three computing devices 106, in some embodiments cloud network 102 comprises fewer (or more) than three computing devices 106.

[0023] Media playback system 100 is configured to receive media content from network 102 via link 103. The received media content may include, for example, a uniform resource identifier (URI) and / or a uniform resource locator (URL). For example, in some examples, media playback system 100 may stream, download, or otherwise obtain data from a URI or URL corresponding to the received media content. Network 104 communicatively couples link 103 with at least some of the devices of media playback system 100 (e.g., one or more of playback device 110, NMD 120, and / or control device 130). Network 104 may include, for example, a wireless network (e.g., a WiFi network, Bluetooth, Z-Wave network, ZigBee, and / or other suitable wireless communication protocol network) and / or a wired network (e.g., a network including Ethernet, Universal Serial Bus (USB), and / or other suitable wired communication). As used herein, as would be understood by one of ordinary skill in the art, "WiFi" can refer to a number of different communication protocols, including, for example, communication protocols transmitted at 2.4 gigahertz (GHz), 5 GHz, and / or another suitable frequency, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ac, 802.11ad, 802.11af, 802.11ah, 802.11ai, 802.11aj, 802.11aq, 802.11ax, 802.11ay, 802.15, etc.

[0024] In some embodiments, network 104 comprises a dedicated communications network that media playback system 100 uses to send messages between individual devices and / or to transmit media content to and from media content sources (e.g., one or more of computing devices 106). In particular embodiments, network 104 is configured to be accessible only to devices within media playback system 100, thereby reducing interference and contention with other home devices. However, in other embodiments, network 104 comprises an existing home communications network (e.g., a home WiFi network). In some embodiments, link 103 and network 104 comprise one or more of the same networks. In some aspects, for example, link 103 and network 104 comprise a communications network (e.g., an LTE network, a 5G network). Furthermore, in some embodiments, media playback system 100 is implemented without network 104, and the devices comprising media playback system 100 can communicate with each other via, for example, one or more direct or indirect connections, PANs, LANs, communications networks, and / or other suitable communications links.

[0025] In some embodiments, audio content sources may be periodically added or removed from media playback system 100. In some embodiments, for example, media playback system 100 performs media item indexing when one or more media content sources are updated, added, and / or removed from media playback system 100. Media playback system 100 may scan for identifiable media items in some or all folders and / or directories accessible to playback device 110 and generate or update a media content database that includes metadata (e.g., title, artist, album, track length) and other associated information (e.g., URI, URL) for each identifiable media item found. In some embodiments, for example, the media content database is stored in one or more of playback device 110, network microphone device 120, and / or control device 130.

[0026] In the illustrated embodiment of FIG. 1B , playback devices 110l and 110m constitute group 107a. Playback devices 110l and 110m can be located in different rooms in a home and can be temporarily or permanently grouped into group 107a based on user input received at control device 130a and / or another control device 130 of media playback system 100. Once arranged in group 107a, playback devices 110l and 110m can be configured to synchronously play the same or similar audio content from one or more audio content sources. In particular embodiments, for example, group 107a includes a combining zone in which playback devices 110l and 110m respectively constitute the left and right audio channels of multi-channel audio content, thereby creating or enhancing a stereo effect for the audio content. In some embodiments, group 107a further includes playback device 110. However, in other embodiments, media playback system 100 omits group 107a and / or other grouping arrangements of playback devices 110. Further details regarding groups and other arrangements of playback devices are described below with reference to Figures 1I-1M.

[0027] Media playback system 100 includes NMDs 120a and 120d having one or more microphones configured to receive voice utterances from a user. In the illustrated embodiment of FIG. 1B , NMD 120a is a standalone device, and NMD 120d is integrated into playback device 110n. NMD 120a is configured to receive voice input 121, for example, from user 123. In some embodiments, NMD 120a transmits data associated with the received voice input 121 to a voice assistant service (VAS) configured to (i) process the received voice input data and (ii) transmit corresponding commands to media playback system 100. In some aspects, for example, computing device 106c comprises one or more modules and / or servers of a VAS (e.g., a VAS operated by one or more of SONOS®, AMAZON®, GOOGLE®, APPLE®, MICROSOFT®). Computing device 106c may receive audio input data from NMD 120a via network 104 and link 103. In response to receiving the audio input data, computing device 106c processes the audio input data (e.g., "Play Hey Jude by The Beatles") and determines that the processed audio input includes a command to play a song (e.g., "Hey Jude"). Computing device 106c responsively transmits a command to media playback system 100 from an appropriate media service (e.g., via one or more of computing devices 106) to play "Hey Jude" by The Beatles on one or more of playback devices 110.

[0028] b. Suitable playback device FIG. 1C is a block diagram of a playback device 110a including input / output 111. Input / output 111 may include analog I / O 111a (e.g., one or more wires, cables, and / or other suitable communication links configured to transmit analog signals) and / or digital I / O 111b (e.g., one or more wires, cables, or other suitable communication links configured to transmit digital signals). In some embodiments, analog I / O 111a is an audio line-in input connection, for example, constituting an auto-sensing 3.5mm audio line-in connection. In some embodiments, digital I / O 111b includes a Sony / Philips Digital Interface Format (S / PDIF) communication interface and / or cable, and / or a Toshiba Link (TOSLINK) cable. In some embodiments, digital I / O 111b includes a High-Definition Multimedia Interface (HDMI®) interface and / or cable. In some embodiments, digital I / O 111b includes one or more wireless communication links, e.g., comprising radio frequency (RF), infrared, WiFi, Bluetooth, or other suitable communication protocols. In particular embodiments, analog I / O 111a and digital I / O 111b may not necessarily include cables, but may include interfaces (e.g., ports, plugs, jacks) configured to accept connectors of cables carrying analog and digital signals, respectively.

[0029] Playback device 110a can receive media content (e.g., audio content consisting of music and / or other sounds) from local audio source 105, for example, via input / output 111 (e.g., cable, wire, PAN, Bluetooth® connection, ad-hoc wired or wireless communication network, and / or another suitable communication link). Local audio source 105 can comprise, for example, a mobile device (e.g., a smartphone, a tablet, a laptop computer) or another suitable audio component (e.g., a television, a desktop computer, an amplifier, a phonograph, a Blu-ray player, memory for storing digital media files). In some aspects, local audio source 105 includes a local music library on a smartphone, a computer, a network-attached storage (NAS), and / or another suitable device configured to store media files. In certain embodiments, one or more of playback device 110, NMD 120, and / or control device 130 comprise local audio source 105. However, in other embodiments, the media playback system omits local audio source 105 entirely. In some embodiments, playback device 110 a does not include input / output 111 and receives all audio content over network 104 .

[0030] Playback device 110a further comprises electronics 112, a user interface 113 (e.g., one or more buttons, knobs, dials, touch-sensitive surfaces, displays, touchscreens), and one or more transducers 114 (hereinafter referred to as “transducers 114”). Electronics 112 is configured to receive audio from an audio source (e.g., local audio source 105) via input / output 111, one or more computing devices 106a-106c ( FIG. 1B ) over network 104, amplify the received audio, and output the amplified audio for playback via one or more transducers 114. In some embodiments, playback device 110a optionally includes one or more microphones 115 (e.g., a single microphone, multiple microphones, a microphone array) (hereinafter referred to as “microphones 115”). In certain embodiments, for example, playback device 110a having optional one or more microphones 115 can operate as an NMD configured to receive audio input from a user and perform one or more corresponding operations based on the received audio input.

[0031] 1C , the electronic device 112 includes one or more processors 112 a (hereinafter referred to as “processor 112 a”), memory 112 b, software components 112 c, a network interface 112 d, one or more audio processing components 112 g (hereinafter referred to as “audio processing components 112 g”), one or more audio amplifiers 112 h (hereinafter referred to as “amplifiers 112 h”), and a power source 112 i (e.g., one or more power supplies, power cables, power outlets, batteries, induction coils, Power-over Ethernet (POE) interfaces, and / or other suitable power sources). In some embodiments, the electronic device 112 optionally includes one or more other components 112 j (e.g., one or more sensors, a video display, a touch screen, a battery charging base).

[0032] As described in more detail elsewhere herein, in some examples, the power component 112i can include one or more of the following: a wireless power transmitter (laser, induction coil, etc.), a wireless power receiver (e.g., a photovoltaic cell, induction coil, etc.), an energy storage component (a capacitor, a rechargeable battery, etc.), an energy harvester, a wired power input port, and / or associated power circuitry. In operation, the playback device 110a is configured to transmit wireless power to one or more external devices. Additionally, or alternatively, the playback device 110a can be configured to receive wireless power from one or more external transmitting devices instead of or in addition to receiving power via a wired connection.

[0033] The processor 112a may comprise a clocked computing component configured to process data, and the memory 112b may include a computer-readable medium (e.g., a tangible, non-transitory computer-readable medium, data storage loaded with one or more of the software components 112c) configured to store instructions for performing various operations and / or functions. The processor 112a is configured to execute the instructions stored in the memory 112b to perform one or more operations. The operations may include, for example, causing the playback device 110a to obtain audio information from an audio source (e.g., one or more of the computing devices 106a-106c (FIG. 1B)) and / or another one of the playback devices 110a. In some embodiments, the operations may further include causing the playback device 110a to transmit the audio information to another one of the playback devices 110a and / or to another device (e.g., one of the NMDs 120). In certain embodiments, the playback device 110a further includes an operation of pairing the playback device 110a with one or more other playback devices 110 to enable a multi-channel audio environment (e.g., stereo pair, combined zone).

[0034] The processor 112a may further be configured to perform operations that cause the playback device 110a to synchronize playback of the audio content with another of the one or more playback devices 110. As will be appreciated by those skilled in the art, during synchronized playback of audio content on multiple playback devices, a listener will preferably be unable to perceive a time delay difference between the playback of the audio content by the playback device 110a and the playback of the audio content by one or more other playback devices 110. Additional details regarding audio playback synchronization between playback devices are described, for example, in U.S. Patent No. 8,234,395, incorporated by reference above.

[0035] In some embodiments, memory 112b is further configured to store data associated with playback device 110a, such as one or more zones and / or zone groups of which playback device 110a is a member, audio sources accessible to playback device 110a, and / or playback queues with which playback device 110a (and / or another of the one or more playback devices) is associated. The stored data may include one or more state variables that are periodically updated and used to describe the state of playback device 110a. Memory 112b may also include data associated with the state of one or more other devices of media playback system 100 (e.g., playback device 110, NMD 120, control device 130). In some aspects, for example, state data is shared among at least some of the devices of media playback system 100 at predetermined time intervals (e.g., every 5 seconds, every 10 seconds, every 60 seconds) so that one or more devices have up-to-date data associated with media playback system 100.

[0036] Network interface 112d is configured to facilitate data transmission between playback device 110a and one or more other devices on a data network, such as link 103 and / or network 104 (FIG. 1B). Network interface 112d is configured to send and receive data corresponding to media content (e.g., audio content, video content, text, photographs) and other signals (e.g., non-transient signals), including digital packet data having Internet Protocol (IP)-based source addresses and / or IP-based destination addresses. Network interface 112d can parse the digital packet data so that electronic device 112 appropriately receives and processes the data intended for playback device 110a.

[0037] In the illustrated embodiment of FIG. 1C , the network interface 112d includes one or more wireless interfaces 112e (hereinafter referred to as “wireless interface 112e”). The wireless interface 112e (e.g., a suitable interface including one or more antennas) may be configured to wirelessly communicate with one or more other devices (e.g., one or more of the other playback devices 110, the NMD 120, and / or the control device 130) communicatively coupled to the network 104 ( FIG. 1B ) according to an appropriate wireless communication protocol (e.g., WiFi, Bluetooth, LTE). In some embodiments, the network interface 112d optionally includes a wired interface 112f (e.g., an interface or receptacle configured to receive a network cable such as an Ethernet, USB-A, USB-C, and / or Thunderbolt cable) configured to communicate over a wired connection with other devices according to an appropriate wired communication protocol. In particular embodiments, the network interface 112d includes the wired interface 112f and excludes the wireless interface 112e. In some embodiments, electronic device 112 omits network interface 112d entirely and transmits and receives media content and / or other data via another communication path (eg, input / output 111).

[0038] Audio processing component 112g is configured to process and / or filter data including media content received by electronic device 112 (e.g., via input / output 111 and / or network interface 112d) to generate an output audio signal. In some embodiments, audio processing component 112g includes, for example, one or more digital-to-analog converters (DACs), audio preprocessing components, audio enhancement components, digital signal processors (DSPs), and / or other suitable audio processing components, modules, circuits, etc. In particular embodiments, one or more of audio processing components 112g may include one or more subcomponents of processor 112a. In some embodiments, electronic device 112 omits audio processing component 112g. In some aspects, for example, processor 112a executes instructions stored in memory 112b to perform audio processing operations to generate the output audio signal.

[0039] The amplifier 112h is configured to receive and amplify the audio output signal generated by the audio processing component 112g and / or the processor 112a. The amplifier 112h may include electronic devices and / or components configured to amplify the audio signal to a level sufficient to drive one or more transducers 114. In some embodiments, for example, the amplifier 112h includes one or more switching or class-D power amplifiers. However, in other embodiments, the amplifier includes one or more other types of power amplifiers (e.g., a linear gain power amplifier, a class-A amplifier, a class-B amplifier, a class-AB amplifier, a class-C amplifier, a class-D amplifier, a class-E amplifier, a class-F amplifier, a class-G amplifier, and / or a class-H amplifier, and / or another suitable type of power amplifier). In particular embodiments, the amplifier 112h includes a suitable combination of two or more of the aforementioned types of power amplifiers. Furthermore, in some embodiments, each amplifier 112h corresponds to an individual transducer 114. However, in other embodiments, the electronics 112 includes a single amplifier 112h configured to output amplified audio signals to multiple transducers 114. In some other embodiments, electronics 112 omits amplifier 112h.

[0040] The transducer 114 (e.g., one or more speakers and / or speaker drivers) receives the amplified audio signal from the amplifier 112h and renders or outputs the amplified audio signal as sound (e.g., audible sound waves having a frequency between approximately 20 Hertz (Hz) and approximately 20 Kilohertz (kHz)). In some embodiments, the transducer 114 may comprise a single transducer. However, in other embodiments, the transducer 114 comprises multiple audio transducers. In some embodiments, the transducer 114 comprises two or more types of transducers. For example, the transducer 114 may include one or more low-frequency transducers (e.g., subwoofers, woofers), a mid-frequency transducer (e.g., mid-range transducer, mid-woofer), and one or more high-frequency transducers (e.g., one or more tweeters). As used herein, "low frequency" can generally refer to audio frequencies below about 500 Hz, "mid frequency" can generally refer to audio frequencies between about 500 Hz and about 2 kHz, and "high frequency" can generally refer to audio frequencies above about 2 kHz. However, in certain embodiments, one or more of the transducers 114 comprise transducers that do not conform to the aforementioned frequency ranges. For example, one of the transducers 114 may comprise a mid-woofer transducer configured to output sound at frequencies between about 200 Hz and about 5 kHz.

[0041] By way of example, Sonos Incorporated currently offers (or has offered) certain playback devices for sale, including, for example, "SONOS ONE," "PLAY:1," "PLAY:3," "PLAY:5," "PLAYBAR," "PLAYBASE," "CONNECT:AMP," "CONNECT," and "SUB." Other suitable playback devices may additionally or alternatively be used to implement the playback devices of the exemplary embodiments disclosed herein. Furthermore, those skilled in the art will appreciate that playback devices are not limited to the exemplary embodiments described herein or to Sonos product offerings. In some embodiments, for example, one or more playback devices 110 comprise wired or wireless headphones (e.g., over-ear headphones, on-ear headphones, in-ear earphones). The headphones may include a headband coupled to one or more ear cups. For example, a first ear cup is coupled to a first end of the headband and a second ear cup is coupled to a second end opposite the first end of the headband. Each of the one or more ear cups may house any portion of the electronic components within the playback device, such as one or more transducers. Additionally, one or more ear cups may include a user interface for controlling operation of the headphones, such as controlling audio playback, volume levels, and other functions. The user interface may include any of a variety of control elements, such as buttons, knobs, dials, touch-sensitive surfaces, and / or touchscreens. Ear cushions may be coupled to each of the one or more ear cups. The ear cushions may provide a soft barrier between the user's head and the one or more ear cups to improve user comfort and / or provide acoustic isolation from the environment (e.g., provide passive noise reduction (PNR)). Additionally (or alternatively), the headphones may employ active noise reduction (ANR) technology to further reduce external noise perceived by the user during playback.

[0042] In some cases, the headphone device may take the form of a hearable device. The hearable device includes a headphone device (e.g., an ear-level device) configured to provide hearing enhancement functionality while also supporting playback of media content (e.g., streaming media content from a user device over a PAN, streaming media content from a streaming music service provider over a WLAN and / or cellular network connection, etc.). In some cases, the hearable device may be implemented as an in-ear headphone device configured to play an amplified version of at least some sounds detected from the external environment (e.g., all sounds, selected sounds such as people speaking, etc.).

[0043] In other embodiments, one or more playback devices 110 include a docking station for a personal mobile media playback device and / or an interface configured to interact with a docking station. In certain embodiments, the playback device may be integrated with another device or component, such as a television, a lighting fixture, or some other device for indoor or outdoor use. In some embodiments, the playback device omits a user interface and / or one or more transducers. For example, FIG. 1D is a block diagram of a playback device 110p that includes input / output 111 and electronics 112, but does not include user interface 113 or transducer 114.

[0044] FIG. 1E is a block diagram of a combined playback device 110q (FIG. 1C) that includes a playback device 110a (FIG. 1C) acoustically coupled with a playback device 110i (e.g., a subwoofer) (FIG. 1A). In the illustrated embodiment, playback devices 110a and 110i are separate playback devices 110 housed in separate enclosures. However, in some embodiments, combined playback device 110q comprises a single enclosure that houses both playback devices 110a and 110i. Combined playback device 110q can be configured to process and reproduce sound differently than uncoupled playback devices (e.g., playback device 110a of FIG. 1C) and / or paired or coupled playback devices (e.g., playback devices 110l and 110m of FIG. 1B). In some embodiments, for example, playback device 110a is a full-range playback device configured to render low-, mid-, and high-frequency audio content, and playback device 110i is a subwoofer configured to render low-frequency audio content. In some aspects, playback device 110a, when combined with a first playback device, is configured to render only mid- and high-frequency components of particular audio content, and playback device 110i is configured to render low-frequency components of particular audio content. In some embodiments, combined playback device 110q includes additional playback devices and / or another combined playback device. Embodiments of additional playback devices are described in further detail below with respect to FIGS. 2A-3D.

[0045] c. Suitable Network Microphone Device (NMD) FIG. 1F is a block diagram of the NMD 120a (FIGS. 1A and 1B). The NMD 120a includes one or more audio processing components 124 (hereinafter referred to as “audio components 124”) and the components described with respect to the playback device 110a (FIG. 1C), including the processor 112a, memory 112b, power source 112i, and microphone 115. As described elsewhere herein, the power component, the power source 112i, may include one or more of a wireless power transmitter (e.g., a laser, an induction coil, etc.), a wireless power receiver (e.g., a photovoltaic cell, an induction coil, etc.), an energy storage component (e.g., a capacitor, a rechargeable battery), an energy harvester, a wired power input port, and / or associated power circuitry. In operation, the NMD 120a can be configured to transmit wireless power to one or more external devices. Additionally or alternatively, the NMD 120a can be configured to receive wireless power from one or more external transmitting devices in addition to, or instead of, receiving power via a wired connection.

[0046] NMD 120a optionally includes other components also included in playback device 110a (FIG. 1C), such as user interface 113 and / or transducer 114. In some embodiments, NMD 120a is configured as a media playback device (e.g., one or more of playback devices 110) and further includes, for example, audio processing component 112g (FIG. 1C), transducer 114, and / or one or more other playback device components. In particular embodiments, NMD 120a comprises an Internet of Things (IoT) device, such as, for example, a thermostat, an alarm panel, a fire detector, and / or a smoke detector. In some embodiments, NMD 120a includes only microphone 115, audio processing 124, and some of the components of electronic device 112 described above with respect to FIG. 1B. In some aspects, for example, NMD 120a includes processor 112a and memory 112b (FIG. 1B), while omitting one or more other components of electronic device 112. In some embodiments, the NMD 120a includes additional components (eg, one or more sensors, a camera, a thermometer, a barometer, a hygrometer).

[0047] In some embodiments, an NMD can be incorporated into a playback device. FIG. 1G is a block diagram of playback device 110r including NMD 120d. Playback device 110r can include many or all of the components of playback device 110a and further includes microphone 115 and audio processing 124 (FIG. 1F). Playback device 110r optionally includes integrated control device 130c. Control device 130c can include, for example, a user interface (e.g., user interface 113 of FIG. 1B) configured to receive user input (e.g., touch input, voice input) without the use of a separate control device. However, in other embodiments, playback device 110r receives commands from another control device (e.g., control device 130a of FIG. 1B). NMD embodiments are described in further detail below with respect to FIGS. 3A-3F.

[0048] Referring again to FIG. 1F, microphone 115 is configured to acquire, capture, and / or receive sound from the environment (e.g., environment 101 of FIG. 1A) and / or the room in which NMD 120a is located. Received sound may include, for example, vocalizations, audio playback by NMD 120a and / or another playback device, background sounds, environmental sounds, etc. Microphone 115 converts the received sound into electrical signals to generate microphone data. Audio processing 124 receives and analyzes the microphone data to determine whether voice input is present in the microphone data. Voice input may include, for example, an activation word followed by a vocalization containing a user request. As will be appreciated by those skilled in the art, an activation word is a word or other audio cue that signifies a user's voice input. For example, when querying an AMAZON® VAS, a user may speak the activation word "Alexa." Other examples include "OK, Google" to invoke the GOOGLE® VAS and "Hey, Siri" to invoke the APPLE® VAS.

[0049] After detecting the hotword, voice processing 124 monitors the microphone data for a user request accompanying the voice input. The user request may include, for example, a command to control a third-party device such as a thermostat (e.g., a NEST® thermostat), a lighting device (e.g., a PHILIPS HUE® lighting device), or a media playback device (e.g., a Sonos® playback device). For example, a user may speak the hotword “Alexa” followed by “set the thermostat to 68 degrees” to set the temperature in a home (e.g., environment 101 of FIG. 1A). A user may speak the same hotword followed by “turn on the living room” to turn on lighting devices in the living room area of ​​the home. A user may similarly speak a hotword followed by a request to play a particular song, album, or music playlist on a playback device in the home. Receiving and processing voice input data is described in further detail below with reference to FIGS. 3A-3F.

[0050] d. Suitable control devices FIG. 1H is a partial schematic diagram of control device 130a (FIGS. 1A and 1B). As used herein, the term “control device” can be used interchangeably with “controller” or “control system.” Among other features, control device 130a is configured to receive user input associated with media playback system 100 and, in response, cause one or more devices in media playback system 100 to perform actions or operations corresponding to the user input. In the illustrated embodiment, control device 130a comprises a smartphone (e.g., iPhone®, Android phone) having media playback system controller application software installed. In some embodiments, control device 130a comprises, for example, a tablet (e.g., iPad®), a computer (e.g., laptop computer, desktop computer), and / or other suitable device (e.g., television, automobile audio head unit, IoT device). In particular embodiments, control device 130a comprises a dedicated controller for media playback system 100. In other embodiments, as described above with respect to FIG. 1G, control device 130a is integrated into another device in media playback system 100 (e.g., one or more of playback device 110, NMD 120, and / or other suitable devices configured to communicate over a network).

[0051] Control device 130a includes electronics 132, a user interface 133, one or more speakers 134, and one or more microphones 135. Electronics 132 includes one or more processors 132a (hereinafter referred to as “processor 132a”), memory 132b, software components 132c, and a network interface 132d. Processor 132a can be configured to perform functions related to facilitating user access, control, and configuration of media playback system 100. Memory 132b can include data storage into which one or more software components executable by processor 302 can be loaded to perform those functions. Software components 132c can include applications and / or other executable software configured to facilitate control of media playback system 100. Memory 112b can be configured to store, for example, software components 132c, media playback system controller application software, and / or other data related to media playback system 100 and the user.

[0052] Network interface 132d is configured to facilitate network communication between control device 130a and one or more other devices in media playback system 100 and / or one or more remote devices. In some embodiments, network interface 132d is configured to operate according to one or more appropriate communications industry standards (e.g., infrared, wireless, wired standards including IEEE 802.3, wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.15, 4G, LTE). Network interface 132d can be configured to transmit and / or receive data, for example, from playback device 110, NMD 120, others of control device 130, one of computing devices 106 of FIG. 1B, one or more other devices comprising the media playback system, etc. The transmitted and / or received data can include, for example, control commands, state variables, playback zone and / or zone group configurations for the playback device. For example, based on user input received at user interface 133, network interface 132d can send playback device control commands (e.g., volume control, audio playback control, audio content selection) from control device 304 to one or more of the playback devices. Network interface 132d can also send and / or receive configuration changes, such as, for example, adding / removing one or more playback devices to a zone, adding / removing one or more zones to a zone group, forming a combined or integrated player, separating one or more playback devices from a combined or integrated player, etc. More details about zones and groups are shown in Figures 1I-1M.

[0053] The user interface 133 is configured to receive user input and can facilitate control of the media playback system 100. The user interface 133 includes media content art 133a (e.g., album art, lyrics, video), playback status indicator 133b (e.g., elapsed time and / or time remaining indicator), media content information area 133c, playback control area 133d, and zone indicator 133e. The media content information area 133c can include a display of relevant information (e.g., title, artist, album, genre, release year) about currently playing media content and / or media content in a queue or playlist. The playback control area 133d can include selectable (e.g., via touch input and / or via a cursor or another suitable selector) icons for causing one or more playback devices in a selected playback zone or zone group to perform playback actions, such as play or pause, fast forward, rewind, skip next, skip previous, enter / exit shuffle mode, enter / exit repeat mode, enter / exit crossfade mode, etc. Playback control area 133d may also include selectable icons for changing equalization settings, playback volume, and / or other suitable playback behavior. In the illustrated embodiment, user interface 133 comprises a display presented on a touchscreen interface of a smartphone (e.g., iPhone®, Android phone). However, in some embodiments, user interfaces of various formats, styles, and interactive sequences may alternatively be implemented on one or more network devices to provide equivalent control access to the media playback system.

[0054] One or more speakers 134 (e.g., one or more transducers) may be configured to output sounds to a user of control device 130a. In some embodiments, one or more speakers comprise individual transducers configured to correspondingly output low, mid, and / or high frequencies. In some aspects, for example, control device 130a is configured as a playback device (e.g., one of playback devices 110). Similarly, in some embodiments, control device 130a is configured as an NMD (e.g., one of NMDs 120) that receives voice commands and other sounds via one or more microphones 135.

[0055] The one or more microphones 135 may include, for example, one or more condenser microphones, electret condenser microphones, dynamic microphones, and / or other suitable types of microphones or transducers. In some embodiments, two or more microphones 135 are positioned to capture location information of an audio source (e.g., voice, audible sound) and / or configured to facilitate filtering of background noise. Furthermore, in certain embodiments, the control device 130a is configured to operate as a playback device and an NMD. However, in other embodiments, the control device 130a omits one or more speakers 134 and / or one or more microphones 135. For example, the control device 130a may comprise a device (e.g., a thermostat, IoT device, network device) that includes a portion of the electronics 132 and a user interface 133 (e.g., a touchscreen) without a speaker or microphone. Additional control device embodiments are described in further detail below with respect to FIGS. 4A-4D and 5.

[0056] e. Proper playback device configuration 1I-1M show exemplary configurations of playback devices in zones and zone groups. Referring first to FIG. 1M, in one example, a single playback device can belong to a zone. For example, playback device 110g in second bedroom 101c (FIG. 1A) may belong to Zone C. In some implementations described below, multiple playback devices can be "combined" to form a "combined pair," which together form a single zone. For example, playback device 110l (e.g., the left playback device) can be combined with playback device 110j (e.g., the right playback device) to form Zone A. Combined playback devices may have different playback responsibilities (e.g., channel responsibilities). In another implementation described below, multiple playback devices can be merged to form a single zone. For example, playback device 110h (e.g., the front playback device) can be merged with playback device 110i (e.g., a subwoofer) and playback devices 110j and 110k (e.g., left and right surround speakers, respectively) to form a single Zone D. In another example, playback devices 110g and 110h can be merged to form merged group or zone group 108b. Merged playback devices 110g and 110h may not be specifically assigned different playback responsibilities. That is, merged playback devices 110h and 110i can each play audio content as if they were not merged, apart from playing audio content synchronously.

[0057] Each zone in media playback system 100 may be provided for control as a single user interface (UI) entity. For example, zone A may be provided as a single entity called the master bathroom, zone B may be provided as a single entity called the master bedroom, and zone C may be provided as a single entity called the second bedroom.

[0058] Combined playback devices may have different playback responsibilities, such as responsibility for specific audio channels. For example, as shown in FIG. 1-I, playback devices 110l and 110m may be combined to create or enhance a stereo effect for audio content. In this example, playback device 110l may be configured to play the left channel audio component, while playback device 110k may be configured to play the right channel audio component. In some implementations, such stereo combining may be referred to as "pairing."

[0059] Furthermore, combined playback devices may have additional and / or different respective speaker drivers. As shown in FIG. 1J, a playback device 110h labeled Front may be combined with a playback device 110i labeled Sub. The Front device 110h may be configured to render a mid- to high-frequency range, and the Sub device 110i may be configured to render low frequencies. However, when not combined, the Front device 110h may be configured to render a full range of frequencies. As another example, FIG. 1K shows the Front device 110h and the Sub device 110i further combined with the Left playback device 110j and the Right playback device 110k, respectively. In some implementations, the Right device 110j and the Left device 110k may be configured to form surround or "satellite" channels of a home theater system. The combined playback devices 110h, 110i, 110j, and 110k may form a single Zone D (FIG. 1M).

[0060] Merged playback devices may not have assigned playback responsibilities and each may be capable of rendering the full range of audio content for which the respective playback device is capable. Nevertheless, merged devices may be represented as a single UI entity (i.e., a zone, as described above). For example, playback devices 110a and 110n in the master bathroom have a single UI entity for Zone A. In one embodiment, playback devices 110a and 110n can each output the full range of audio content for which each playback device 110a and 110n is capable in sync.

[0061] In some embodiments, an NMD is combined or merged with another device to form a zone. For example, NMD 120b may be combined with playback device 110e, which together form zone F, referred to as the living room. In other embodiments, a standalone network microphone device may itself be within a zone. However, in other embodiments, a standalone network microphone device may not be associated with a zone. Further details regarding associating network microphone devices and playback devices as designated or default devices can be found, for example, in the above-referenced U.S. Patent Application Publication No. 15 / 438,749.

[0062] Zones of individual, combined, and / or merged devices may be grouped to form zone groups. For example, referring to FIG. 1M, zone A may be grouped with zone B to form zone group 108a containing the two zones. Similarly, zone G may be grouped with zone H to form zone group 108b. As another example, zone A may be grouped with one or more other zones C1. Zones A-I may be grouped and ungrouped in numerous ways. For example, three, four, five, or more (e.g., all) of zones A-I may be grouped. Once grouped, zones of individual and / or combined playback devices may play audio in synchronization with one another, as described in the previously referenced U.S. Pat. No. 8,234,395. Playback devices may also be dynamically grouped and ungrouped to form new or different groups that play audio content in synchronization.

[0063] In various implementations, a zone within an environment may be a combination of the default names of the zones within the group or the names of the zones within the zone group. For example, zone group 108b may be assigned a name such as "dining + kitchen," as shown in FIG. 1M. In some embodiments, a zone group may be given a unique name selected by the user.

[0064] Certain data may be stored in the memory of the playback device (e.g., memory 112b of FIG. 1C) as one or more state variables that are periodically updated and used to describe the state of the playback zone, playback device, and / or its associated zone group. The memory may also contain data that is associated with the state of other devices in the media system and that is shared from time to time between devices so that one or more of the devices have the most current data associated with the system.

[0065] In some embodiments, the memory can store instances of various variable types associated with states. The variable instances can be stored with an identifier (e.g., a tag) corresponding to the type. For example, a particular identifier can be a first type "a1" to identify a playback device in a zone, a second type "b1" to identify playback devices that can be combined within the zone, and a third type "c1" to identify a zone group to which the zone can belong. As a related example, an identifier associated with the second bedroom 101c can indicate that the playback device is the only playback device in zone C and not within a zone group. An identifier associated with the den can indicate that the den is not grouped with other zones but includes combined playback devices 110h-110k. An identifier associated with the dining room can indicate that the dining room is part of the dining + kitchen zone group 108b and that devices 110b and 110d are grouped together (FIG. 1L). An identifier associated with the kitchen can indicate the same or similar information by the kitchen being part of the dining + kitchen zone group 108b. Other exemplary zone variables and identifiers are described below.

[0066] In yet another example, media playback system 100 can store variables or identifiers representing other associations of zones and zone groups, such as identifiers associated with areas, as shown in FIG. 1M. Areas can include clusters of zone groups and / or zones not within a zone group. For example, FIG. 1M shows upper area 109a including zones A-D and lower area 109b including zones E-I. In one aspect, an area can be used to refer to a cluster of zone groups and / or zones that share one or more zones and / or zone groups of another cluster. In another aspect, this is different from a zone group that does not share a zone with another zone group. Further examples of techniques for implementing areas can be found, for example, in U.S. Patent Application Publication No. 15 / 682,506, filed August 21, 2017, entitled "Room Association Based on Name," and U.S. Patent Application Publication No. 8,483,853, filed September 11, 2007, entitled "Controlling and Manipulating Groupings in a Multi-Zone Media System." Each of these applications is incorporated herein by reference in its entirety. In some embodiments, media playback system 100 may not implement areas, in which case the system may not store variables associated with areas.

[0067] III. Exemplary Systems and Devices FIG. 2A is a front isometric view of a playback device 210 configured in accordance with an embodiment of the disclosed technology. FIG. 2B is a front isometric view of the playback device 210 without the grill 216e. FIG. 2C is an exploded view of the playback device 210. Referring together to FIGS. 2A-2C, the playback device 210 includes a housing 216 including an upper portion 216a, a right or first side 216b, a lower portion 216c, a left or second side 216d, a grill 216e, and a rear portion 216f. A plurality of fasteners 216g (e.g., one or more screws, rivets, clips) attach a frame 216h to the housing 216. A cavity 216j (FIG. 2C) within the housing 216 is configured to receive the frame 216h and the electronic device 212. Frame 216h is configured to carry a plurality of transducers 214 (individually identified in FIG. 2B as transducers 214a-f). Electronics 212 (e.g., electronics 112 of FIG. 1C) is configured to receive audio content from an audio source and transmit electrical signals corresponding to the audio content to transducers 214 for playback.

[0068] The transducers 214 are configured to receive electrical signals from the electronics 112 and are further configured to convert the received electrical signals into audible sounds during playback. For example, the transducers 214a-214c (e.g., tweeters) can be configured to output high-frequency sounds (e.g., sound waves having frequencies above approximately 2 kHz). The transducers 214d-214f (e.g., mid-woofers, woofers, mid-range speakers) can be configured to output sounds at lower frequencies than the transducers 214a-214c (e.g., sound waves having frequencies below approximately 2 kHz). In some embodiments, the playback device 210 includes several transducers different from those shown in FIGS. 2A-2C. For example, as described in further detail below with respect to FIGS. 3A-3C, the playback device 210 can include fewer than six transducers (e.g., 1, 2, 3). However, in other embodiments, the playback device 210 includes more than six transducers (e.g., 9, 10). Additionally, in some embodiments, all or some of the transducers 214 are configured to operate as a phased array to desirably adjust (e.g., narrow or wide) the radiation pattern of the transducers 214, thereby altering the user's perception of the sound emanating from the playback device 210.

[0069] 2A-2C, filter 216i is axially aligned with transducer 214b. Filter 216i can be configured to desirably attenuate a predetermined frequency range output by transducer 214b to improve the sound quality and perceived sound stage collectively output by transducers 214. However, in some embodiments, playback device 210 omits filter 216i. In other embodiments, playback device 210 includes one or more additional filters aligned with transducer 214b and / or at least another of transducers 214.

[0070] In some examples, the playback device 210 can be configured as a portable playback device, such as an ultra-portable playback device with an internal power source. FIG. 2D shows an example of a housing 241 of such a portable playback device. As shown, the portable playback device housing 241 includes a user interface in the form of a control area 242 on a top 244 of the housing 241. The control area 242 can include a capacitive touch sensor for controlling audio playback, volume level, and other functions. The portable playback device housing 241 can be configured to mate with a dock 246 that connects to an external power source via a cable 248. The dock 246 can be configured to provide power to the portable playback device and recharge its internal battery. In some embodiments, the dock 246 can be configured with a set of one or more conductive contacts (not shown) located on the top of the dock 246 that mate with conductive contacts (not shown) on the bottom of the housing 241. In other examples, the dock 246 can provide power to the portable playback device from the cable 248 without using conductive contacts. For example, the dock 246 may wirelessly charge the portable playback device via one or more induction coils integrated into the dock 246 and the portable playback device, respectively.

[0071] In some examples, the playback device 210 can take the form of wired and / or wireless headphones (e.g., over-ear headphones, on-ear headphones, or in-ear headphones). For example, FIG. 2E shows an exemplary housing 250 for such an embodiment of the playback device 210. As shown, the housing 250 includes a headband 252 that couples a first earbud 254a to a second earbud 254b. Each of the earpieces 254a and 254b can house any portion of the electronic components within the playback device, such as one or more speakers and one or more microphones. In some embodiments, the housing 250 can enclose or carry one or more microphones. Additionally, one or more of the earpieces 254a and 254b can include a control area 258 for controlling audio playback, volume level, and other functions. The control area 258 can be comprised of any combination of capacitive touch sensors, buttons, switches, and dials. 2D , housing 250 can further include ear cushions 256 a and 256 b coupled to earpieces 254 a and 254 b, respectively. Ear cushions 256 a and 256 b can provide a soft barrier between a user's head and earpieces 254 a and 254 b, respectively, to improve user comfort and / or provide acoustic isolation from the environment (e.g., passive noise reduction (PNR)). In some implementations, wired and / or wireless headphones can be powered by an internal energy source and can be ultra-portable playback devices weighing 50 ounces (1417 g) or less.

[0072] In some examples, the playback device 210 can take the form of an in-ear headphone device. Apart from headphones, the playback device 210 may also take the form of other wearable devices. Wearable devices include devices configured to be worn on a part of the subject (e.g., the head, neck, torso, arm, wrist, finger, leg, ankle, etc.). For example, the playback device 210 can take the form of eyeglasses including a frame front (e.g., configured to hold one or more lenses), a first temple rotatably coupled to the frame front, and a second temple rotatably coupled to the frame front. In this example, the eyeglasses can include one or more transducers integrated into at least one of the first and second temples and configured to project sound toward the subject's ears.

[0073] While specific implementations of playback microphone devices and network microphone devices have been described herein, numerous configurations of devices exist, including, but not limited to, those without a UI, microphones in different locations, multiple microphone arrays arranged in different configurations, and / or other configurations appropriate to the requirements of a given application. For example, the UI and / or microphone arrays may be implemented in other playback devices and / or computing devices other than those described herein. Furthermore, while specific examples of playback device 210 have been described with reference to MPS 100, those skilled in the art will recognize that the playback devices described herein can be used in a variety of different environments, including, but not limited to, environments with more and / or fewer elements, without departing from the invention. Similarly, the MPS described herein can be used with a variety of different playback devices.

[0074] 3A and 3B are front and right isometric side views, respectively, of an NMD 320 configured in accordance with an embodiment of the disclosed technology. FIG. 3C is an exploded view of the NMD 320. FIG. 3D is an enlarged view of a portion of FIG. 3B including a user interface 313 of the NMD 320. Referring initially to FIGS. 3A-3C, the NMD 320 includes a housing 316 having an upper portion 316a, a lower portion 316b, and a middle portion 316c (e.g., a grille). A plurality of ports, holes, or openings 316d in the upper portion 316a allow sound to pass to one or more microphones 315 (FIG. 3C) disposed within the housing 316. The one or more microphones 316 are configured to receive sound via the openings 316d and generate electrical signals based on the received sound. In the illustrated embodiment, frame 316e of housing 316 (FIG. 3C) encloses cavities 316f and 316g configured to house first transducer 314a (e.g., a tweeter) and second transducer 314b (e.g., a mid-woofer, mid-range speaker, or woofer), respectively. However, in other embodiments, NMD 320 includes a single transducer, or three or more (e.g., two, five, or six) transducers. In certain embodiments, NMD 320 omits transducers 314a and 314b entirely.

[0075] Electronics 312 (FIG. 3C) includes components configured to drive transducers 314a and 314b and further configured to analyze audio information corresponding to electrical signals generated by one or more microphones 315. In some embodiments, for example, electronics 312 includes many or all of the components of electronics 112 described above with respect to FIG. 1C. In particular embodiments, electronics 312 includes the components described above with respect to FIG. 1F, such as, for example, one or more processors 112a, memory 112b, software components 112c, network interface 112d, etc. In some embodiments, electronics 312 includes additional suitable components (e.g., proximity or other sensors).

[0076] Referring to FIG. 3D , user interface 313 includes multiple control surfaces (e.g., buttons, knobs, capacitive surfaces) including first control surface 313a (e.g., previous control), second control surface 313b (e.g., next control), and third control surface 313c (e.g., play and / or pause control). Fourth control surface 313d is configured to receive touch input corresponding to activation and deactivation of one or more microphones 315. First indicator 313e (e.g., one or more light-emitting diodes (LEDs) or another suitable lighting device) may be configured to illuminate only when one or more microphones 315 are activated. Second indicator 313f (e.g., one or more LEDs) may remain illuminated during normal operation and may be configured to flash or otherwise change from illuminated to indicate detection of voice activity. In some embodiments, user interface 313 includes additional or fewer control surfaces and lighting devices. In one embodiment, for example, user interface 313 includes first indicator 313e without second indicator 313f. Additionally, in certain embodiments, NMD 320 comprises a playback device and a control device, and user interface 313 comprises a user interface of the control device.

[0077] 3A-3D together, the NMD 320 is configured to receive voice commands from one or more nearby users via one or more microphones 315. As described above with respect to FIG. 1B, the one or more microphones 315 can acquire, capture, or record sounds in the vicinity (e.g., an area within 10 meters of the NMD 320) and transmit electrical signals corresponding to the recorded sounds to the electronics 312. The electronics 312 can process the electrical signals and analyze the resulting audio data to determine the presence of one or more voice commands (e.g., one or more activation words). In some embodiments, for example, after detecting one or more appropriate voice commands, the NMD 320 is configured to transmit a portion of the recorded audio data to another device and / or a remote server (e.g., one or more of the computing devices 106 of FIG. 1B) for further analysis. The remote server can analyze the audio data, determine an appropriate action based on the voice command, and send a message to the NMD 320 to perform the appropriate action. For example, a user can utter, "Sonos, play Michael Jackson." The NMD 320 can record the user's voice utterances via one or more microphones 315, determine the presence of a voice command, and transmit audio data having the voice command to a remote server (e.g., one or more of the remote computing devices 106 of FIG. 1B, one or more servers of a VAS, and / or another suitable service). The remote server can analyze the audio data and determine an action corresponding to the command. The remote server can then transmit a command to the NMD 320 to perform the determined action (e.g., play audio content related to Michael Jackson). The NMD 320 can receive this command and play audio content related to Michael Jackson from a media content source.1B, suitable content sources may include devices or storage communicatively coupled to the NMD 320 via a LAN (e.g., network 104 of FIG. 1B), a remote server (e.g., one or more of the remote computing devices 106 of FIG. 1B), etc. However, in certain embodiments, the NMD 320 determines and / or performs one or more actions corresponding to one or more voice commands without the intervention or involvement of an external device, computer, or server.

[0078] 3E is a functional block diagram illustrating further features of an NMD 320 according to an aspect of the present disclosure. The NMD 320 includes components configured to facilitate voice command capture, including a voice activity detector component 312k, a beamformer component 312l, an acoustic echo cancellation (AEC) and / or self-sound suppression component 312m, a hot word detector component 312n, and a voice / speech conversion component 312o (e.g., voice-to-text and text-to-voice). In the illustrated embodiment of FIG. 3E, the aforementioned components 312k-312o are shown as separate components. However, in some embodiments, one or more of the components 312k-312o are subcomponents of the processor 112a.

[0079] The beamforming and self-sound suppression components 312l and 312m are configured to detect audio signals and determine aspects of the voice input represented in the detected audio signals, such as direction, amplitude, and frequency spectrum. The voice activity detector activity component 312k is operatively coupled to the beamforming and AEC components 312l and 312m and configured to determine one or more directions from which voice activity is likely occurring in the detected audio signals. Potential speech directions can be identified by monitoring metrics that distinguish speech from other sounds. Such metrics can include, for example, entropy in the speech band, which is a measure of the energy and spectral structure in the speech band relative to background noise. As will be appreciated by those skilled in the art, speech generally has lower entropy than most common background noises. The hotword detector component 312n is configured to monitor and analyze the received audio to determine whether any hotwords (e.g., wake words) are present in the received audio. The hotword detection component 312n can analyze the received audio using a hotword detection algorithm. If the hotword detector 312n detects a hotword, the NMD 320 can process the voice input included in the received audio. An example hotword detection algorithm accepts audio as input and provides an indication of whether a hotword is present in the audio. Many first-party and third-party hotword detection algorithms are known and commercially available. For example, a voice service operator may make an algorithm available for use with third-party devices. Alternatively, an algorithm may be trained to detect a specific hotword. In some embodiments, the hotword detector 312n runs multiple hotword detection algorithms simultaneously (or substantially simultaneously) on the received audio. As previously mentioned, different voice services (e.g., AMAZON'S ALEXA®, APPLE'S SIRI®, or MICROSOFT'S CORTANA®) may each use different hotwords to invoke their respective voice services. To support multiple services, the hotword detector 312n may run the received audio through a hotword detection algorithm for each supported voice service in parallel.

[0080] The speech-to-text component 312o can facilitate processing by converting speech in the voice input into text. In some embodiments, the electronic device 312 can include voice recognition software that is trained for a particular user or a particular set of users associated with the household. Such voice recognition software can implement voice-processing algorithms that are tailored to a particular voice profile. Tailoring to a particular voice profile may require less computationally intensive algorithms than traditional voice activity services that sample from a variety of requests that generally do not target a broad base of users and media playback systems.

[0081] 3F is a schematic diagram of an example of an audio input 328 captured by an NMD 320 according to an aspect of the present disclosure. The audio input 328 may include a hotword portion 328a and a voice utterance portion 328b. In some embodiments, the hotword 557a may be a known hotword, such as "Alexa," associated with AMAZON'S ALEXA®. However, in other embodiments, the audio input 328 may not include a hotword. In some embodiments, the network microphone device may output an audible and / or visible response upon detection of the hotword portion 328a. Additionally or alternatively, the NMD may output an audible and / or visible response after processing the audio input and / or a series of audio inputs.

[0082] Audio utterance portion 328b may include, for example, one or more spoken commands (individually identified as first command 328c and second command 328e) and one or more spoken keywords (individually identified as first keyword 328d and second keyword 328f). In one example, first command 328c may be a command to play music, such as a particular song, album, playlist, etc. In this example, the keywords may be one or more words identifying one or more zones in which music is to be played, such as the living room and dining room shown in FIG. 1A. In some examples, audio utterance portion 328b may include other information, such as detected pauses (e.g., periods of non-speech) between words spoken by the user, as shown in FIG. 3F. The pauses may define the location of distinct commands, keywords, or other information spoken by the user within audio utterance portion 328b.

[0083] In some embodiments, the media playback system 100 is configured to temporarily reduce the volume of the audio content being played while detecting the hot word portion 557a. The media playback system 100 can restore the volume after processing the audio input 328, as shown in FIG. 3F. Such a process can be referred to as ducking, examples of which are disclosed in U.S. Patent Application No. 15 / 438,749, which is incorporated herein by reference in its entirety.

[0084] 4A-4D are schematic diagrams of a control device 430 (e.g., control device 130a of FIG. 1H, a smartphone, a tablet, a dedicated control device, an IoT device, and / or another suitable device) showing corresponding user interface displays in various operating states. First user interface display 431a (FIG. 4A) includes a display name 433a (i.e., "Room"). Selected group area 433b displays audio content information (e.g., artist name, track name, album art) for audio content being played in the selected group and / or zone. Group areas 433c and 433d display the corresponding group and / or zone name, as well as audio content information and audio content playing or next to be played in the play queue for the respective group or zone. Audio content area 433e includes information about the audio content in the selected group and / or zone (i.e., the group and / or zone shown in selected group area 433b). Lower display area 433f is configured to receive touch input and display one or more other user interface displays. For example, if the user selects "Browse" in lower display area 433f, control device 430 can be configured to output a second user interface display 431b (FIG. 4B) that includes multiple music services 433g (e.g., Spotify, Radio by Tune In, Apple Music, Pandora, Amazon, TV, Local Music, Line In), from which the user can browse for and select media content for playback via one or more playback devices (e.g., one of playback devices 110 of FIG. 1A). Alternatively, if the user selects "My Songs" in lower display area 433f, control device 430 can be configured to output a third user interface display 431c (FIG. 4C).First media content region 433h can include a graphical representation (e.g., album art) corresponding to an individual album, station, or playlist. Second media content region 433i can include a graphical representation (e.g., album art) corresponding to an individual song, track, or other media content. When a user selects graphical representation 433j (FIG. 4C), control device 430 can be configured to begin playing audio content corresponding to graphical representation 433j and output fourth user interface display 431d including an enlarged version of graphical representation 433j, media content information 433k (e.g., track name, artist, album), transport controls 433m (e.g., play, rewind, fast forward, pause, volume), and a display 433n of the currently selected group and / or zone name.

[0085] 5 is a schematic diagram of a control device 530 (e.g., a laptop computer, a desktop computer). The control device 530 includes a transducer 534, a microphone 535, and a camera 536. The user interface 531 includes a transport control area 533a, a playback status area 533b, a playback zone area 533c, a playback queue area 533d, and a media content source area 533e. The transport control area includes one or more controls for controlling media playback, including, for example, volume, previous, play / pause, next, repeat, shuffle, track position, crossfade, equalization, etc. The audio content source area 533e includes a list of one or more media content sources from which the user can select media items for playback and / or addition to the playback queue.

[0086] The playback zones area 533b may include representations of playback zones within the media playback system 100 (FIGS. 1A and 1B). In some embodiments, the graphical representations of the playback zones may be selectable to display additional selectable icons for managing or configuring the playback zones in the media playback system, such as creating combined zones, creating zone groups, separating zone groups, and renaming zone groups. In the illustrated embodiment, a “group” icon is provided within each of the graphical representations of the playback zones. The “group” icon provided within the graphical representation of a particular zone may be selectable to display options for selecting one or more other zones within the media playback system to be grouped with the particular zone. Once grouped, playback devices within a zone grouped with the particular zone can be configured to play audio content in synchronization with the playback devices in the particular zone. Similarly, a “group” icon may be provided within the graphical representation of a zone group. In the illustrated embodiment, the “group” icon may be selectable to display options for deselecting one or more zones within the zone group to be removed from the zone group. In some embodiments, the control device 530 includes other interactions and implementations for grouping and ungrouping zones via the user interface 531. In certain embodiments, the representation of the play zones in play zone region 533b may be dynamically updated as the play zone or zone group configuration changes.

[0087] Playback status area 533c includes a graphical representation of audio content currently playing, previously playing, or next scheduled to play in the selected playback zone or zone group. The selected playback zone or zone group may be visually distinguished in the user interface, such as in playback zone area 533b and / or play queue area 533d. The graphical representation may include track title, artist name, album name, album year, track length, and other relevant information that may be useful for a user to know when controlling media playback system 100 via user interface 531.

[0088] The play queue area 533d includes a graphical representation of the audio content in the play queue associated with the selected playback zone or zone group. In some embodiments, each playback zone or zone group may be associated with a play queue that includes information corresponding to zero or more audio items for playback by the playback zone or zone group. For example, each audio item in the play queue may comprise a uniform resource identifier (URI), a uniform resource locator (URL), or some other identifier that can be used by a playback device in the playback zone or zone group to find and / or retrieve the audio item from local or networked audio content sources, as the case may be, for playback by the playback device. In some embodiments, for example, a playlist may be added to the play queue, and information corresponding to each audio item in the playlist may be added to the play queue. In some embodiments, the audio items in the play queue may be saved as a playlist. In certain embodiments, the play queue may be empty or pre-populated but "unused" when the playback zone or zone group is continuously playing streaming audio content, such as Internet radio, that can otherwise continue to play until stopped, rather than individual audio items with playback durations. In some embodiments, the playback queue may include internet radio and / or other streaming audio content items and may be "in use" when a playback zone or zone group is playing those items.

[0089] When playback zones or zone groups are "grouped" or "ungrouped," the playback queues associated with the affected playback zones or zone groups can be cleared or reassociated. For example, if a first playback zone containing a first playback queue is grouped with a second playback zone containing a second playback queue, the established zone group can initially have playback queues that are empty, contain audio items from the first playback queue (e.g., if the second playback zone is added to the first playback zone), contain audio items from the second playback queue (e.g., if the first playback zone is added to the second playback zone), or are associated with a combination of audio items from both the first and second playback queues. If the established zone group is subsequently ungrouped, the resulting first playback zone may be reassociated with the previous first playback queue, or may be associated with a new playback queue that is empty or contains audio items from the playback queues associated with the established zone group before the established zone group was ungrouped. Similarly, the resulting second playback zone may be reassociated with the previous second playback queue, or may be associated with a new playback queue that is empty or contains audio items from the playback queue associated with the established zone group before the established zone group was ungrouped.

[0090] FIG. 6 is a message flow diagram illustrating data exchange between devices in media playback system 100 (FIGS. 1A-1M).

[0091] At step 650a, media playback system 100 receives, via control device 130a, an indication of selected media content (e.g., one or more songs, albums, playlists, podcasts, videos, stations). The selected media content may include, for example, media items stored locally on one or more devices connected to the media playback system (e.g., audio source 105 of FIG. 1C) and / or media items stored on one or more media service servers (e.g., one or more of remote computing devices 106 of FIG. 1B). In response to receiving the indication of the selected media content, control device 130a sends message 651a to playback device 110a (FIGS. 1A-1C) to add the selected media content to a playback queue of playback device 110a.

[0092] In step 650b, playback device 110a receives message 651a and adds the selected media content to a playback queue for playback.

[0093] In step 650c, the control device 130a receives an input corresponding to a command to play the selected media content. In response to receiving the input corresponding to the command to play the selected media content, the control device 130a sends a message 651b to the playback device 110a, causing the playback device 110a to play the selected media content. In response to receiving message 651b, the playback device 110a sends a message 651c to the first computing device 106a requesting the selected media content. In response to receiving message 651c, the first computing device 106a sends a message 651d including data (e.g., audio data, video data, a URL, a URI) corresponding to the requested media content.

[0094] In step 650d, playback device 110a receives message 651d with data corresponding to the requested media content and plays the associated media content.

[0095] In step 650e, playback device 110a optionally causes one or more other devices to play the selected media content. In one example, playback device 110a is one of a combined zone of two or more players (FIG. 1M). Playback device 110a can receive the selected media content and transmit all or part of the media content to other devices in the combined zone. In another example, playback device 110a is a group coordinator and is configured to send and receive timing information from one or more other devices in the group. One or more other devices in the group can receive the selected media content from first computing device 106a and begin playing the selected media content in response to a message from playback device 110a, such that all devices in the group play the selected media content synchronously.

[0096] IV. WIRELESS POWER TRANSFER DEVICE, RELATED SYSTEM, AND METHODS Wirelessly powered audio playback devices offer several distinct advantages over traditional wired devices. For example, there is no need to unsightly hide power cords in walls or under furniture. Wireless power also allows users to more easily rearrange devices within a home or room without disconnecting or rewiring power cords. To enable this functionality, one or more wireless power transmitting devices can be provided in proximity to an audio playback device that has a wireless power receiver within it. Such transmitting devices can include another playback device (e.g., a soundbar, subwoofer, or any playback device with a wired power connection) or a non-playback device (e.g., a power hub that provides wireless power to a playback device without driving its own audio output). In some examples, one or more playback devices can include both a wireless power receiver and a wireless power transmitter, and these devices can be used in either configuration, and in some cases simultaneously (e.g., as a “relay,” where the device receives wireless power from an external transmitting device and transmits wireless power to an external receiving device). In one embodiment, multiple such playback devices can transfer wireless power to each other in a mesh configuration, with the particular inter-device transfer selected to provide the desired power levels, device performance, and user experience.

[0097] As used herein, a "wireless power transmitter" or "transmitter device" includes any device (or component of a device) capable of transmitting wireless power that can be received and collected by an appropriate receiver device. Similarly, a "wireless power receiver" or "receiver" includes any device (or component of a device) capable of receiving wireless power from a remote transmitter and utilizing that power to operate one or more components of the receiver (e.g., powering at least one amplifier of a playback device). In various embodiments, a single playback device (or other apparatus) can be both a wireless power transmitter and a wireless power receiver, while in other embodiments, a particular apparatus can be only a transmitter or only a receiver.

[0098] In various examples disclosed herein, such wireless power transmission may include medium-range or long-range wireless power transmission. As used herein, medium-range and long-range wireless power transmission includes wireless power transmission at distances greater than about 10 cm, and in some examples, greater than about 50 cm, or greater than about 1 meter. For example, the wireless power transmitter and wireless power receiver may be separated from each other by at least about 10 cm, at least about 50 cm, or at least about 1 meter during wireless power transmission.

[0099] As noted elsewhere herein, such medium- or long-range wireless power transmission technologies include radiative technologies (e.g., laser, radio wave, microwave, or electromagnetic radiation propagating from a transmitter to a receiver, etc.). In various examples, the wireless power receiver in such examples may include a photovoltaic cell, a diode, an antenna (e.g., a rectenna), or other suitable hardware capable of converting electromagnetic radiation into electrical energy. Similarly, the wireless power transmitter in such cases may include a light source such as a laser, a microwave source, an antenna (e.g., a directional antenna, a phased array antenna, etc.), or other suitable electromagnetic radiation source.

[0100] Additionally or alternatively, such medium- or long-range wireless power transmission may include non-radiative transmission, such as electromagnetic coupling (e.g., inductive coupling, resonant inductive coupling, capacitive coupling, resonant capacitive coupling, magnetodynamic coupling, etc.). In such examples, both the wireless power transmitter and the wireless power receiver may include a conductive coil (e.g., in the case of inductive coupling), an electrode (e.g., in the case of capacitive coupling), or a rotating armature having a magnet thereon (e.g., in the case of magnetodynamic coupling). a. Components of an appropriate wireless power transmission device

[0101] 7 is a schematic block diagram of a wireless power transmission (WPT) apparatus 700. In some examples, the wireless power transmission apparatus 700 may be coupled to, integrated with, or included within a playback device (e.g., playback device 110a in FIG. 1C), an NMD (e.g., NMD 120a in FIG. 1F), or other suitable device.

[0102] 7, a wireless power transmission apparatus 700 includes one or more processors 702, a network interface 704, and a memory 706, which may be similar to or identical to and include the processor 112a, the network interface 112d, and the memory 112b described above with respect to FIGS. 1C and 1F. In various embodiments, the wireless power transmission apparatus 700 may include any or all of the features of the playback device 110a or the NMD 120a described previously herein. In some examples, the network interface 704 may include one or more transceivers configured to communicate over at least one WIFI network and / or at least one BLUETOOTH network.

[0103] The wireless power transmission apparatus 700 optionally includes a wired power input port 708 configured to be electrically coupled to a wired power source 710 (e.g., via a 110 / 220V wall power source, a USB-C charger, etc.), such as an AC power port or a USB port (e.g., a USB-TYPE-A port, a USB-TYPE-B port, a USB-TYPE-C port, etc.). The power input port 708 can be directly coupled to a household power outlet (e.g., via a cable) (e.g., to receive alternating current (AC) power) or indirectly coupled via a power adapter (e.g., a device that converts AC power from a household power outlet to direct current (DC) power). In some examples, the wired power input port 708 is omitted, and the wireless power transmission apparatus 700 operates solely based on power received wirelessly from external transmitting device(s) and / or energy 716 generated via energy harvester(s).

[0104] The wireless power transmission device 700 further includes an energy storage component 712, which may take the form of a rechargeable battery, a capacitor, a supercapacitor, or any other suitable component capable of storing energy. The energy storage component 712 may be configured to store energy and facilitate operation of the device (e.g., powering one or more amplifiers of a playback device). In this regard, the energy storage component 712 may be a battery having a chemistry that facilitates battery recharging, such as lithium-ion (Li-ion), nickel-metal hydride (NiMH), or nickel-cadmium (NiCd). The battery may be sized to enable the processor 702 and other components of the wireless power transmission device 700 to operate solely on battery power for extended periods of time without the need to recharge the battery. For example, the battery may have a capacity of 20 watt-hours (Wh) and provide at least four hours of continuous audio playback on battery power alone. The battery can be charged using power from one or more other components within the wireless power transmitter 700 (e.g., the wired power input port 708, the wireless power transmitter 720, the energy harvester 716, etc.).

[0105] As mentioned above, in some examples, wireless power transmission apparatus 700 can include audio reproduction components 714 (e.g., one or more transducers, audio processing circuitry, microphones, voice processing circuitry, etc.), and as such, wireless power transmission apparatus 700 can include or be part of an audio reproduction device or networked microphone device as described elsewhere herein. In various examples, such an audio reproduction device can be a sound bar, a subwoofer, a headphone device, a hearable device, a portable audio reproduction device, an architectural reproduction device, or a video reproduction device.

[0106] The wireless power transmission apparatus 700 optionally includes one or more energy harvesters 716. The energy harvesters 716 may include devices configured to obtain power from energy sources in the environment (e.g., solar energy, thermal energy, wind energy, salinity gradients, kinetic energy, sound energy, etc.). For example, the energy harvesters 716 may include one or more photovoltaic cells configured to convert received light into voltage. Any of a variety of energy harvesters 716 may be included in the wireless power transmitter 700. Examples of such energy harvesters include photovoltaic cells, thermoelectric generators, micro-wind turbines, piezoelectric crystals, electro-acoustic transducers, kinetic energy harvesters, etc.

[0107] The wireless power transmission apparatus 700 further includes a wireless power transmitter 718, a wireless power receiver 720, and a power supply circuit 722. In operation, the wireless power transmission apparatus 700 can receive wireless power from an external transmitting device via the receiver 720 and can transmit wireless power to an external receiving device via the transmitter 718, with the power supply circuit 722 controlling some or all of the functions related to these operations.

[0108] The wireless power transmitter 718 can include any component or combination of components capable of transmitting wireless power to an external wireless power receiver. Such wireless power transmission can include medium-range or long-range wireless power transmission, for example, configured to provide effective power transmission when the transmitter and receiver are separated by a distance of more than about 10 cm, and in some examples, more than about 50 cm, or more than about 1 meter. In various examples, the wireless power transmitter 718 can transmit power by a radiation technique, such as using a laser, radio wave, microwave, or other such technique involving the propagation of electromagnetic radiation from a transmitter to a receiver. In various embodiments, such electromagnetic radiation can be directional (e.g., directed toward one or more receivers) or omnidirectional (e.g., radiated in substantially all directions from the wireless power transmitter 718). In various examples, the wireless power transmitter 718 in such examples can include a light source such as a laser, a microwave source, an antenna (e.g., a directional antenna, a phased array antenna, etc.), or any other source of electromagnetic radiation. In some embodiments, the wireless power transmitter 718 may include one or more steering components configured to direct, focus, or steer the wireless power. Such steering components may include, for example, one or more lenses, mirrors, directional antennas, or other suitable components.

[0109] Additionally or alternatively, the wireless power transmitter 718 may be configured to transmit wireless power using a non-radiative technique, such as electromagnetic coupling (e.g., inductive coupling, resonant inductive coupling, capacitive coupling, resonant capacitive coupling, magneto-dynamic coupling, etc.). In such examples, the wireless power transmitter 718 may include a conductive coil (e.g., in the case of inductive coupling), an electrode (e.g., in the case of capacitive coupling), a rotating armature carrying a magnet thereon (e.g., in the case of magneto-dynamic coupling), or any other suitable structure capable of receiving power wirelessly via electromagnetic coupling.

[0110] The wireless power receiver 720 may include any component or structure configured to receive power wirelessly (e.g., via inductance, resonance, radiation, etc.) from an external wireless transmitter. As previously described, such wireless power transmission may include medium- or long-range wireless power transmission, for example, configured to provide effective power transmission while the transmitter and receiver are separated from each other by a distance of more than about 10 cm, and in some examples, more than about 50 cm, or more than about 1 meter. In various embodiments, the wireless power receiver 720 may receive power via a radiation technique such as laser, radio wave, microwave, or other such technique involving the propagation of electromagnetic radiation from a transmitter to a receiver. The wireless power receiver 720 in such cases may include an optical receiver such as a diode, a photovoltaic cell, an antenna (e.g., a rectenna), or other suitable hardware capable of converting electromagnetic radiation into electrical energy.

[0111] Additionally or alternatively, the wireless power receiver 720 may be configured to receive wireless power using a non-radiative technique, such as electromagnetic coupling (e.g., inductive coupling, resonant inductive coupling, capacitive coupling, resonant capacitive coupling, magnetodynamic coupling, etc.). In such examples, the wireless power receiver 720 may include a conductive coil (e.g., in the case of inductive coupling), an electrode (e.g., in the case of capacitive coupling), a rotating armature carrying a magnet thereon (e.g., in the case of magnetodynamic coupling), or any other suitable structure capable of receiving power wirelessly via electromagnetic coupling.

[0112] 7 , the wireless power transmission device 700 may include a power supply circuit 722 configured to receive power from the energy storage component (capacitor) 712, the wired power input 708, and / or the wireless power receiver 720 and use the resulting power to drive an amplifier and / or electro-acoustic transducer having an audio output based on the source audio. The power supply circuit 722 may be configured to perform any of a variety of power-related tasks, including, for example, one or more of the following: (1) power conversion (e.g., AC-AC conversion, AC-DC conversion, DC-AC conversion, and / or DC-DC conversion), (2) power conditioning, (3) battery charging, and / or (4) power monitoring (e.g., battery monitoring). Examples of electrical components that may be integrated into the power supply circuit 722 include a transformer, a rectifier, an inverter, a converter, a regulator, a battery charger, and / or a power management integrated circuit (PMIC). In some examples, such a power supply circuit 722 may be integrated into either or both of the wireless power transmitter 718 and the wireless power receiver 720.

[0113] In some examples, the power supply circuitry 722 may include a battery circuit that facilitates monitoring the status of the battery. In these examples, the battery circuitry may determine battery status information including information regarding one or more of the following battery conditions: state of charge (SoC), temperature, age, and / or internal impedance. The battery circuitry may communicate the battery status information to, for example, the processor 702.

[0114] The power supply circuit 722 may include a regulation circuit that facilitates converting a variable amount of voltage (e.g., a variable voltage from a battery, a variable voltage from an energy harvester, etc.) into a stable DC voltage. For example, the regulation circuit may include a switching regulator circuit, such as a buck, boost, buck-boost, flyback, resonant, etc. The regulation circuit may include one or more linear voltage regulators, such as a low dropout (LDO) regulator. The regulation circuit may be configured to output one or more fixed DC voltages (e.g., ±5 V, ±12 V) or an AC voltage. b. Wireless Power Group Example

[0115] FIG. 8 illustrates interactions between power groups including multiple WPT (wireless power transmission) devices that can transmit power and / or data to one another. In the example shown in FIG. 8, the group includes a power group coordinator 800 and first and second power group members 850a, 850b. The power group coordinator 800 and the power group members 850a, 850b can each include some or all of the components described above with respect to the wireless power transmission device 700 of FIG. 7. In some examples, some or all of these devices include or can be audio playback devices. While the illustrated group includes three devices, in various embodiments, there could be one, two, four, five, or more power group members (not shown).

[0116] As used herein, a "power group" can include two or more devices configured to wirelessly transmit power therebetween. In the illustrated example, the coordinator 800 transmits wireless power to each of the first power group member 850a and the second power group member 850b (e.g., via the wireless power transmitter 718). Additionally, the first group member 850a wirelessly transmits power to the second power group member 850b. In alternative examples, the power group coordinator 800 can enable each device in the group to wirelessly receive or transmit power to at least one other device in the group, thereby allowing one or more group members 850 to transmit power to other group members 850 or to wirelessly transmit power to fewer than all members of the wireless power group.

[0117] In the illustrated example, the power group coordinator 800 does not include a wireless power receiver 720 and is connected to a wired power source 710. However, in other embodiments, the power group coordinator 800 does not have a connection to a wired power source 710 and is itself powered solely via wireless power transmission and / or energy harvesting. In some examples, one or more of the power group members 850 may be connected to a wired power source instead of, or in addition to, receiving power wirelessly from other group members.

[0118] As used herein, a “power group coordinator” may include a wireless power transmission device configured to send instructions to one or more power group members to start, stop, or modulate wireless power transmission therebetween. For example, the power group coordinator may cause a first power group member 850a to start wireless power transmission to a second power group member 850b. As described in more detail elsewhere herein, in some examples, wireless power transmission may be started, stopped, or modified based on a number of parameters (e.g., device battery level, level or rate or wireless power received at the device, audio playback level, etc.). In some examples, such parameters may be determined by or transmitted to the power group coordinator 800, which may then determine any appropriate modifications to wireless power transmission within the group and transmit instructions to the group members accordingly.

[0119] In at least some instances, there is no power coordinator, and in such cases, each wireless power transmitter can independently decide whether, how, and when to transmit or receive power wirelessly from an external transmitting and receiving device.

[0120] As mentioned above, in some examples, multiple audio-playing devices may be grouped together for synchronized audio playback (e.g., as a combined zone). In such cases, one of the playback devices may act as a coordinator for the group and may send and receive timing information from one or more other devices in the group. In various examples, a power group may be the same as an audio-playing group. Alternatively, a power group may be at least partially distinct from any audio-playing group. In at least some examples, the power group coordinator 800 may also serve as the audio-playing group coordinator. In such cases, the power group coordinator 800 may transmit timing data or other information to group members via a wireless network and / or via data embedded in a wireless power signal, as described in more detail elsewhere herein. Alternatively, the power group coordinator 800 and the audio-playing group coordinator may be different devices. In still other examples, a power group may be formed without audio-playing grouping, in which case an audio-playing group coordinator may not be present. V. Example Systems and Methods for Charging a Battery in a Reproduction Device

[0121] Systems and methods are disclosed for charging power storage, such as batteries, of playback devices associated with a media playback system. Using the disclosed systems and methods, the media playback system can employ one or more charging schemes for each battery of one or more playback devices that reduce battery degradation and extend battery life compared to conventional approaches. The media playback system can be comprised of one or more playback devices, including at least one playback device (e.g., a portable device) having its own power storage (e.g., a battery) and an associated power source, such as a portable USB charger plugged into an electrical outlet, a wireless charging cradle, or a wireless power transmission system configured to wirelessly charge one or more devices, configured to charge the power storage according to one or more charging schemes. For example, in conventional systems, each power storage is charged to its maximum charging capacity as quickly as the hardware and power source allow. The disclosed media playback system provides an alternative charging scheme configured to reduce degradation of the power storage and extend its useful life. For example, after receiving an instruction to form a group of two or more playback devices for synchronized audio playback, the media playback system may obtain power parameters associated with one or more of the playback devices, such as the power level, lifespan, and / or temperature of each of their power storages, the power charging rate associated with their current charging scheme(s), the playback responsibility of each playback device in the group, and the capabilities of each playback device in the group (e.g., peak power capability, ability to play low-frequency content). If the playback device includes one or more energy harvesters, the power parameters may include an indication of power received via the one or more energy harvesters, the rate at which the one or more energy harvesters are able to harvest energy, etc. These power parameters may be transmitted by the playback device itself to one or more other playback devices via one or more network interfaces.In another example, the power parameters are obtained via another computing device, such as a server that stores or otherwise maintains information about the power parameters of the playback devices, a controller device (e.g., a remote control, smartphone, tablet, etc.), an IoT device, a power source, etc. Based on one or more of these power parameters, the media playback system can identify one or more other charging schemes for each of the devices and configure the playback devices to charge according to the corresponding charging schemes. For example, one charging scheme may reduce the target charge level of one of the storage batteries to a charge level below its maximum charge capacity. As another example, one charging scheme may charge different power stores at different charge rates so that playback devices with lower power storage levels are charged faster than playback devices with higher power storage levels and / or so that the power storage levels of each of the playback devices reach corresponding threshold charge levels substantially simultaneously. After one or more charging schemes are identified, the media playback system can employ the identified charging schemes, for example, by changing the current charging scheme of the playback devices, replacing one charging scheme with another, combining and / or scheduling multiple charging schemes, etc. The media playback system may then revert from one charging scheme to a previous charging scheme, e.g., by modifying or replacing the charging scheme. For example, after receiving an instruction to ungroup one or more playback devices, the media playback system may revert the charging scheme of one or more playback devices to a previous charging scheme, such as a charging scheme that was previously replaced, changed, etc.

[0122] In one charging scheme, a battery is charged at a fixed charging rate to a threshold or target charge level (e.g., a predetermined percentage of capacity, such as 30%, 50%, 75%, 90%, 95%, 100%, etc.). The fixed charging rate may be a predetermined charging rate based on the battery itself, such as a recommended charging rate provided by the battery and / or playback device manufacturer, a charging rate provided by a testing or rating agency, or a charging rate governed by the hardware capacity of the corresponding device and charger. The recommended charging rate provided by the manufacturer, testing agency, etc. may be included as part of a “recommended charging rate range” corresponding to a range of charging rates likely to minimize battery performance degradation. In some cases, the media playback system may query the playback device for a recommended charging rate or a recommended charging rate range. In some examples, the media playback system may query one or more remote computing devices to request a recommended charging rate or a recommended charging rate range. In certain examples, the recommended charging rate or a recommended charging rate range is adjusted or changed based on the battery's lifespan, charging cycles, etc.

[0123] When the battery reaches a threshold, the charging scheme may cause the media playback system to adjust the charging rate to a slower or trickle charge rate to maintain the charge level at the threshold. In some cases, the charging scheme includes a minimum charge level for the battery, and the battery is only charged when it falls below the minimum charge level. In this charging scheme, the battery's charge is set to be below a certain threshold that could damage the battery and accelerate battery degradation. Therefore, this charging scheme reduces battery degradation compared to conventional charging schemes. In some cases, when a predetermined charge capacity percentage is below a certain threshold (e.g., 40%, 60%, etc.), the media playback system may notify one or more users that the corresponding device is only charged up to the certain threshold, allowing the user to select a different charging scheme, for example, if the user plans to use the playback device without a charger (i.e., while the playback device is not plugged in).

[0124] In another charging scheme, the playback device's battery is charged based on the playback device's usage patterns (e.g., when the playback device is used, how the playback device is used, the type of content played by the playback device, when and how often the playback device is connected to a charger, etc.). In this way, the media playback system can be configured to predict the playback device's battery needs and charge the battery accordingly. The media playback system can track playback device usage statistics to determine when and how the playback device is used and use that information to build and / or select a playback device charging scheme. For example, assume that a playback device is regularly used every weekday from a start time of 6:00 PM to an end time of 8:00 PM, consuming an average of 950 milliampere hours (mAh) of charge from its corresponding battery during that time. In this case, the media playback system can predict that the playback device's battery will require approximately 950 mAh at 6:00 PM on weekdays and allow the playback device to be used during the two-hour window. Thus, the media playback system may develop and employ a charging scheme that charges the playback device's battery to, for example, the lesser of: a) a predetermined percentage (e.g., 110%, 120%, 150%) of the playback device's average consumption during a usage window (i.e., in this example, 6:00 PM to 8:00 PM), or b) a predetermined threshold of the battery's maximum capacity, before switching to a charging rate (e.g., a low recommended charging rate or a trickle charging rate) sufficient to maintain this target charge level. In some cases, the predetermined percentage of the playback device's average consumption is determined by analyzing usage statistics (e.g., over the past week, month, year, etc.), constructing one or more distributions (e.g., normal distributions) of, for example, start time and duration based on the usage statistics, and calculating a target charge level based on the distribution parameters (e.g., mean, variance, standard deviation, etc.). For example, constructing one or more distributions (e.g., normal distributions) of start time and duration based on the usage statistics, and calculating a target charge level, such as 1.5 standard deviations above the average consumption value (e.g., 950 mAh) for a particular start time based on the distribution parameters (e.g., mean, variance, standard deviation, etc.).In some cases, the media playback system uses machine learning techniques to build predictive models (e.g., forecasting models, time series models, etc.) that predict, for example, when and for how long a playback device will be used, how much charging that usage will require, etc. Based on this information, the media playback system can build and / or adopt a charging scheme that provides sufficient charging for the predicted usage window. Additionally, the media playback system can monitor the performance of the predictive model and feed this information back into the predictive model to improve the predictive model's performance over time. For example, the media playback system can periodically update the model's training set with usage information, along with an indication of whether the charging provided for the predicted usage window was insufficient, sufficient, excessive, etc. For example, if the media playback system determines that the playback device is periodically returned to the charger (e.g., plugged in) before the end of the predicted usage window with a charge level at or near some predetermined threshold (e.g., 0%, 5%, 15%), the media playback system can provide data to the predictive model indicating that the predicted charge level was insufficient. The predictive model can be updated (e.g., retrained) to reflect this new information. This charging scheme keeps the battery charge relatively low, but provides enough charge to power the device for the expected usage window, and therefore causes less battery degradation than traditional charging schemes.

[0125] In some cases, a media playback system includes a group of devices configured to operate in synchronized playback of the same media content. Users who plan to use these playback devices at an event may want to charge each device in anticipation of the event. However, each device may have a different charge level and require different times to charge using conventional charging technologies. Alternatively, the devices may have the same or substantially the same charge level, but one of the devices may have a battery with a substantially different battery state, such that at least one device charges at a significantly different rate than one or more other devices.

[0126] In this arrangement, the media playback system can employ a charging scheme based on the playback devices and their corresponding batteries in the group. For example, if two or more playback devices are grouped, the media playback system can employ a respective charging scheme configured to bring the battery of each playback device to a target charge level by a target time. In some examples, the media playback system can query each playback device about its current battery status (e.g., current charge, current charge rate, maximum charge rate, safe or recommended charge rate range, maximum capacity, temperature, battery life, lifetime battery charge cycles, etc.) and determine the time it takes for each playback device's battery to charge at or near its highest recommended charge rate (e.g., to reach the target charge level). After this is determined, the media playback system can identify the playback device whose battery takes the longest time to charge, determine the time for that battery to reach the target charge level, and then employ a charging scheme for each playback device so that the batteries of each playback device finish charging (e.g., reach the target charge level) at substantially the same time. In this charging scheme, the batteries of playback devices in the group are not charged to a target charge level at a potentially damaging charging rate while waiting for the batteries of other playback devices in the group to charge to the target charge level. Therefore, this charging scheme can reduce battery degradation for the group as a whole compared to traditional charging schemes. The media playback system can periodically poll the playback devices and update the charging scheme to actively or dynamically respond to changes in the status of the playback devices in the group. In some cases, the media playback system allows a user to override the charging scheme of one or more playback devices to charge their batteries more quickly, for example, by selecting a different charging scheme, such as the charging scheme described herein or a traditional charging scheme. In this manner, the batteries of grouped playback devices can be configured to charge according to the same or different charging schemes.

[0127] In some examples, the regeneration device may include a system or mechanism for harvesting or otherwise receiving energy from alternative sources, such as electromagnetic energy harvesting (e.g., solar, radio frequency (RF), induction, etc.), mechanical energy harvesting (e.g., piezoelectric, vibration, torsion, etc.), and thermodynamic energy harvesting (e.g., heat, chemical reaction, etc.). In some examples, the alternative power source may include one or more wireless power sources, such as one or more examples described above with respect to FIGS. 7 and 8. Charging schemes may utilize these energy harvesting systems by charging the battery to a threshold or target charge level (e.g., a predetermined percentage of capacity, such as 30%, 45%, 50%, 85%, etc.) and allowing the remaining capacity to be charged via an energy harvesting source (e.g., solar panel(s)), a wireless charging device, etc.). As described above, the media playback system can track device usage statistics, including when the alternative energy harvesting system is available to harvest energy (e.g., during the day for solar panels, or during the user's regular commute or exercise routine for kinetic systems), and charge the corresponding battery to a target charge level before the alternative energy harvesting period, for example, based on the average amount of energy the harvesting system is able to harvest during this period. This charging scheme allows the playback device's battery to utilize slower and / or safer alternative energy sources, thereby extending the battery's lifespan and reducing the cost of charging the battery compared to traditional charging schemes. Similarly, the media playback system can employ a charging scheme based on time-of-day or time-of-use electricity rates by scheduling the battery to be charged when electricity rates are low, for example, as determined based on a pricing schedule provided by a utility company or service.

[0128] In some cases, the media playback system extends the battery life of a playback device by changing one or more playback responsibilities of the playback device. For example, if the battery power of a playback device is low (e.g., below a predetermined charge level threshold), the media playback system can determine whether the playback responsibilities of that device can be offloaded (some processing transferred to another device) or adjusted (e.g., turned off, reduced, reconfigured, etc.). To reduce power consumption by the playback device, the media playback system can, for example, reduce playback of audio content including frequencies below a predetermined threshold frequency (e.g., 100 Hz, 300 Hz) by sending instructions to the playback device to reduce playback of frequencies below the predetermined threshold frequency. As will be appreciated by those skilled in the art, frequencies associated with the low-frequency range (below approximately 250 Hz) and low-midrange (e.g., between approximately 250 Hz and approximately 500 Hz) generally consume more power to play than frequencies in other ranges (e.g., above approximately 500 Hz). To conserve battery charge, the media playback system and / or playback device may adjust the playback device's auto-tuning features, dynamic equalization, sampling rate to analyze playback or sound quality, etc. As another example, a microphone associated with the playback device may be disabled or periodically turned on and off to conserve power.

[0129] As another example, a playback device may switch communication technologies from one requiring more power to one requiring less power (e.g., from WiFi to Bluetooth) to extend battery life. In some cases, the media playback system may offload these functions or responsibilities (or portions thereof) to another device (or devices), such as a playback device with a higher charge level that is currently charging. For example, when a headphone battery drops below a certain threshold, the media playback system may transition playback from the headphones to another device. The media playback system may warn the user before this transition to avoid playback from the headphones transitioning to a quiet room or playback from party speakers transitioning to the headphones. The playback device may be configured to make these adjustments automatically when its battery reaches a predetermined charge threshold. In this way, the disclosed media playback system reduces power consumption of the playback device(s) with the least remaining charge and / or playback time compared to conventional approaches, thereby extending the playback time of these playback devices and extending the user's enjoyment of the media playback system. In certain examples, the portable playback device can identify a corded playback device (or perhaps another battery-powered device with a higher charge level) in the same zone or room, or in an adjacent zone or room, and automatically switch playback to that device based on the charge level of the portable playback device.

[0130] 9-11 illustrate exemplary methods in accordance with the present technology. Methods 900, 1000, and 1100 may be performed by any of the devices described herein or other devices now known or later developed. Various embodiments of methods 900, 1000, and 1100 include one or more operations, functions, or acts illustrated by blocks. While the blocks are illustrated in processing order, these blocks may also be performed in parallel and / or in a different order than disclosed and described herein. Additionally, various blocks may be combined into fewer blocks, divided into additional blocks, or eliminated based on the desired implementation.

[0131] Furthermore, for methods 900, 1000, and 1100, as well as other processes and methods disclosed herein, flowcharts illustrate the functionality and operation of possible implementations of some embodiments. In this regard, each block may represent a component, module, segment, or portion of program code, and includes one or more instructions executable by one or more processors to implement specific logical functions or steps in the process. The program code may be stored on any type of computer-readable medium, such as storage devices including disks and hard drives. Computer-readable media may include tangible, non-transitory computer-readable media for storing short-term data, such as register memory, processor cache, and random access memory (RAM). Computer-readable media may also include non-transitory media, such as secondary or persistent long-term storage devices, such as read-only memory (ROM), optical or magnetic disks, and compact disc read-only memory (CD-ROM). Computer-readable media may also be other volatile or non-volatile storage systems. Computer-readable media may be considered, for example, a computer-readable storage medium or a tangible storage device. Furthermore, for the methods disclosed herein and other processes and methods, each block in FIGS. 9-11 may represent circuitry wired to perform a particular logical function in the process.

[0132] 9 shows an example method 900 for updating a charging scheme for one or more playback devices in accordance with some embodiments of the disclosed technology. Referring to FIG. 9, method 900 begins at block 905 with identifying a device. As another example, the playback system may identify a playback device in proximity to media playback based on a determination that the media playback system and the playback device are communicatively coupled via a common local area network, based on a determination that they are in direct wireless communication (e.g., Bluetooth, NFC, Ultra Wideband (UWB), etc.), based on a received signal strength indicator (RSSI), based on an audible chirp emitted by one device and detection via one or more microphones of another device, or based on any other suitable approach.

[0133] In blocks 910-925, the media playback system loops through each identified device to determine an appropriate charging scheme for the device and configures the device to charge according to the charging scheme. In block 915, the media playback system determines a charging scheme for the currently selected device. The charging scheme may be a conventional charging scheme, a charging scheme described herein, or a charging scheme selected by a user in response to a prompt, for example, via a controller device. In some cases, the charging scheme may be automatically determined based on parameters of the currently selected device, the device's usage history, etc. For example, if the charge level of the battery of the currently selected device is below one or more charging thresholds, the media playback system may select a charging scheme that charges the battery of the currently selected device at a predetermined charge rate associated with the corresponding charging thresholds. As another example, a charging scheme may be selected that attempts to charge the battery of the currently selected device to a predetermined percentage of capacity (e.g., 55%, 80%, 90%, 95%, etc.) within a predetermined period (e.g., 30 minutes, 1 hour, 4 hours, etc.), and then charge the device at a predetermined charge rate, such as a low recommended charge rate or a trace charge rate. As another example, a charging scheme may be selected that charges the battery of the currently selected device as slowly as possible. In block 920, the media playback system configures the currently selected device to be charged in accordance with the selected charging scheme, for example, by sending an indication of the selected charging scheme to the device, periodically sending charging instructions to the device according to a charging schedule or itinerary associated with the charging scheme, etc. In block 925, if identified devices remain, the media playback system loops back to block 910 to select the next device; otherwise, the media playback system proceeds to block 930.

[0134] In block 930, the media playback system receives an instruction to form a group of playback devices. This instruction may come from a user, from a playback device, or may be automatically generated by the media playback system itself when it determines that two or more playback devices are in close proximity (e.g., connected to the same network, in the same room, etc.). In block 935, the media playback system invokes a device enumeration (forward-forward) component of the media playback system, such as method 1000 described below with reference to FIG. 10, to obtain a list of devices in the group and ascertain various attributes about those devices, such as the charge level or other parameters associated with each device. In blocks 940-955, the media playback system loops through each enumerated device and updates each device's charging scheme as needed. If, in decision block 945, the charging scheme of the currently selected enumerated device needs to be modified or changed, the media playback system proceeds to block 950; otherwise, the media playback device proceeds to block 955. For example, if the instruction to form a group includes a time parameter (e.g., date, time, etc.), the media playback system may select a charging scheme for each device that will bring the device to a predetermined charge level by the time specified by the time parameter or by a time determined from the time parameter. As another example, and as described above, the media playback system may identify the device in the group whose battery is last to be charged (i.e., to a predetermined charge level) and charge the battery of each of the other devices so that each playback device is charged substantially simultaneously. In block 950, the media playback system configures the currently selected device to charge according to the newly selected or changed charging scheme. In block 955, if enumerated devices remain, the media playback device loops back to block 940 to select the next enumerated device; otherwise, method 900 is complete.Those skilled in the art will recognize that any number of events may prompt a media playback system or device to update or modify its charging scheme, such as a warning from the device that the battery charge level is below or about to fall below a particular charging threshold, a manual request from a user, notification that a device has been added or removed from a group or region of devices, etc. Similarly, a media playback system may periodically (e.g., hourly, daily, etc.) check the status of the playback device and determine whether a change in its charging scheme is warranted.

[0135] FIG. 10 illustrates an example method 1000 for enumerating devices in a media playback system by identifying those devices and checking various attributes of those devices, in accordance with some embodiments of the disclosed technology. Referring to FIG. 10, method 1000 begins at block 1010 with identifying a device. For example, the media playback system may access a device directory or manifest associated with a group of playback devices to identify the device. As another example, the playback system may identify playback devices in proximity to the media playback system. In blocks 1020-1060, the media playback system loops through each of the enumerated devices and checks various attributes of the enumerated devices. In block 1030, the media playback system determines the charge level of the device, for example, by querying the playback device or its battery for its charge level (and / or charge capacity). In block 1040, the component determines device parameters, such as a recommended charging rate or range associated with the device, a list of features the device possesses (e.g., hardware features, software features, audio features, etc.), an indication of whether and / or to what extent the device can fulfill certain responsibilities during synchronized playback (e.g., broadcast audio to the room versus headphones, bass response, communication with a control device, etc.), and performance metrics associated with the device. In block 1050, the media playback system determines the device's location, such as its geographic location, an indication of the room or playback zone in which the device is located, and the device's proximity to one or more other devices. In some cases, the media playback system uses UWB and / or acoustic technology to determine the device's relative location (e.g., distance and direction) and / or orientation. The location of the device can affect playback responsibilities, power requirements, etc. For example, a satellite further back may require less low-frequency content. Similarly, the relative location and / or orientation can affect acoustic output with respect to beamforming, speaker directional strategy, bass cutoff strategy, etc.In block 1060, if identified devices remain, the media playback system loops back to block 1020 to select the next device; otherwise, method 1000 returns a list of identified devices and their corresponding attributes. In some examples, the media playback system may cache or otherwise store the list of enumerated devices (and their corresponding attributes) and invoke the enumerate devices component only if they have not been enumerated within a previous predetermined period (e.g., last five minutes, last hour, last day, etc.).

[0136] FIG. 11 illustrates an exemplary method 1100 for shifting device responsibilities in a media playback system from one device to another, in accordance with some embodiments of the disclosed technology. Method 1100 may be invoked by the media playback system, e.g., via a playback device, a controller device, etc., in response to determining that an identified device is low on power, disconnected from a charging source, disconnected from a group of synchronized devices, responding to a request from a user, etc. Referring to FIG. 11, method 1100 begins at block 1105 by invoking a device enumeration component of the media playback system to identify available candidate devices to take over the responsibilities of the identified device and verifying various attributes of those identified devices, as in method 1000 described above with reference to FIG. 10. In block 1110, the media playback system identifies features (or player features) of the identified device that can be offloaded, e.g., by querying the identified device for a list of these features, comparing the identified device's features to a list of features that can be offloaded or shifted to another device, etc. In some cases, this list is maintained by the media playback system and / or provided by the device manufacturer, a third party, etc.

[0137] In blocks 1115-1155, the media playback system loops through each of the identified features (or player features) of the identified device and attempts to adjust those features or offload responsibility for those features to another device. In blocks 1120-1145, the media playback system loops through each enumerated device. In some cases, the media playback system first ranks the enumerated devices based on, for example, charge level, ability to perform or execute the currently selected feature (e.g., based on performance metric attributes identified via the enumerate device component), etc., and then loops through the enumerated devices in ranked order. If, in decision block 1125, the media playback system determines that the currently selected feature of the identified device can be offloaded to the currently selected enumerated device, the media playback system proceeds to block 1130; otherwise, the media playback system proceeds to block 1145. This determination may be made, for example, by querying the currently selected enumerated device to determine whether it can perform the currently selected function, checking a list provided by the enumerated device component to determine whether the currently selected function is supported by the currently selected enumerated device, determining whether synchronized playback and / or the currently selected function are location-sensitive, and if so, determining whether the currently selected enumerated device is in an appropriate location to perform the currently selected function, etc. In block 1130, the media playback system sends a request to the currently selected enumerated device to take over responsibility for the currently selected function. In some examples, the media playback system also sends a notification to the user indicating that responsibility for the currently selected function will be transferred from the identified device to the currently selected enumerated device, which the user can accept or decline.At decision block 1135, if the request is accepted, the media playback system proceeds to block 1140; otherwise, the media playback system proceeds to block 1145. At block 1140, the media playback system offloads the currently selected function to the currently selected enumerated device by, for example, enabling the function at the currently selected enumerated device, disabling the function at the identified device, streaming any communications, messages, or signals related to the function to the currently selected enumerated device, notifying other devices of the change in responsibility, etc., and then proceeds to select another function at block 1155. In some cases, rather than immediately offloading or transferring responsibility, the media playback system may transfer responsibility over a predetermined period of time (e.g., 30 seconds, 5 minutes, etc.). For example, the media playback system may increase the volume and / or bass output of the currently selected enumerated device while gradually decreasing the volume and / or bass output of the identified device. In some cases, rather than offloading responsibility for a function from the identified device to one of the enumerated devices, the media playback system may offload responsibility to multiple devices. In block 1145, if enumerated devices remain, the media playback system loops back to block 1120 to select the next enumerated device. In block 1150, if the identified device was unable to offload responsibility for the currently selected function (e.g., because none of the enumerated devices had the capability or would accept the request, because the user denied the request, etc.), the media playback system attempts to adjust the currently selected function by, for example, turning off the function, reducing the function, etc. In some cases, the media playback system may inform the user that the function could not be offloaded and prompt the user to select how to adjust the function.In block 1155, if there are remaining features, media playback loops back to block 1115 to select the next feature, otherwise method 1100 is complete. In some cases, the media playback system periodically analyzes available playback devices to determine when, under current conditions, the batteries of one or more of the playback devices will reach a predetermined threshold level and attempts to shift responsibility for the device in advance of that time.

[0138] 12A-12D show examples of device charging schemes according to the disclosed technology. Referring together to FIGS. 12A-12D, a first playback device 1210a (e.g., a portable playback device such as a Sonos Roam) has a first state according to a set of one or more first parameters (e.g., device parameters, playback responsibilities, environmental / context parameters, player capability parameters, and / or battery parameters such as current charge, current charge rate, maximum charge rate, safe or recommended charge rate range, maximum capacity, temperature, battery age, life battery charge cycles, etc.). The battery of the first playback device 1210a receives power according to a first charging scheme 1280a from a power source (e.g., a power cord / cable plugged into an outlet, a vehicle power receptacle, Power over Ethernet (POE), another battery, one or more other playback devices, an energy harvester, a wireless power source, etc.). The second playback device 1210b has a second state according to one or more second sets of parameters and receives power from a power source (either the same power source as the first playback device, a different power source, and / or a combination thereof) according to a second charging scheme 1280b. In the illustrated example of FIG. 12A, the first playback device 1210a and the second playback device 1210b may be operating in an ungrouped state. Alternatively, for example, one or both devices may be members (or coordinators) of different groups and / or combined zones.

[0139] In some examples, the media playback system can receive an instruction (e.g., via the control device or via one of the playback devices) to form a new group or combined zone consisting of the first playback device 1210a and the second playback device 1210b, or to join an existing group or combined zone. In some examples, the first playback device 1210a and the second playback device 1210b automatically form a new group or combined zone (or join an existing group or combined zone) in response to a trigger (e.g., detection of proximity of one device to the other device, detection of proximity of both devices to a third device, detection of a listener, time of day, detection of multi-channel audio, detection of a line input on a display device such as a television, etc.).

[0140] 12B illustrates a first playback device 1210a and a second playback device 1210b as part of a group and / or combined zone, where the two devices are configured to output the same media content (or individual channels of the same media content) synchronously or substantially synchronously. FIG. 12B illustrates that the first playback device 1210a is configured to charge according to a charging scheme 1280c, and the second playback device 1210b is configured to charge according to a charging scheme 1280d. In some examples, charging schemes 1280a and 1280c are the same, and charging schemes 1280b and 1280d are the same. However, in other examples, charging scheme 1280c differs from charging scheme 1280a based on one or more parameters of the first playback device 1210a and / or the second playback device 1210b.

[0141] For example, according to charging scheme 1280a, the first playback device 1210a may be charged to a first target threshold (e.g., 90%) at a first charge rate. Similarly, according to charging scheme 1280b, the second playback device may be charged to a second target threshold (e.g., 95%) at the first charge rate or another charge rate. Upon joining a group (or joining zone), charging scheme 1280c may be adjusted to match the second target threshold. In some examples, as described above, charging schemes 1280c and 1280d are updated to reflect different charge levels between the batteries of the first playback device 1210a and the second playback device 1210b. For example, the first playback device 1210a may have a first charge level (e.g., 70%), and the second playback device 1210b may have a second charge level (e.g., 30%). In this scenario, charging according to charging scheme 1280c (rather than charging scheme 1280a) may consist of adjusting the rate at which the battery of the first playback device 1210a is charged at a slower rate so that the first and second playback devices 1210a and 1210b reach their target thresholds substantially simultaneously.

[0142] In some examples, the charging scheme 1280c is adjusted to reflect differences in playback (or other) responsibilities between the ungrouped and grouped states of either the first playback device 1210a or the second playback device 1210b. For example, the first and second charging schemes 1280a and 1280b may have the same (or substantially the same) target charging threshold (e.g., 90%, 95%, 98%). However, after grouping, the second playback device 1210b may be assigned specific playback responsibilities such that, while grouped or combined, the second playback device 1210b is expected to consume a different amount of power than the first playback device 1210a, even if the devices are of similar age and have similar batteries. For example, in some examples, after the devices are grouped, the second playback device 1210b may be assigned responsibility for voice commands such that its onboard voice engine is activated. In these scenarios, operating a voice engine on both devices may be redundant, so the voice engine on the first playback device 1210a may be correspondingly deactivated. Thus, charging scheme 1280c may have a first target charge level (e.g., 70%, 80%, 90%) that differs from charging scheme 1280d's second target charge level (e.g., 90%, 95%, 100%) by an offset (e.g., 10%, 20%, 30%) indicating the delta between the power consumption of the portable device with an active voice engine (e.g., the second playback device 1210b) and the portable device with an inactive voice engine (e.g., the first playback device 1210a). In some examples, the first and second playback devices 1210a and 1210b may instead periodically alternate active voice engine responsibilities so that no single one of the devices needs to have an excessively high target charge level (e.g., greater than 95%, 98%, or 99%). In some examples, the charge rate of the charging scheme 1280c is based, at least in part, on an offset between the first and second target charge levels.

[0143] In some examples, one or more other parameters of either the first or second playback device 1210a and 1210b can cause adjustment of the charging schemes 1280c and / or 1280d. For example, when entering grouping mode, if the second playback device 1210b is designated as the group coordinator and the first playback device 1210a is designated as a group member, the charging schemes 1280c and 1280d can be adjusted to reflect an offset between the first and second target charge levels that indicates the difference in expected power consumption between the group coordinator and the group member(s).

[0144] In some examples, the first playback device 1210a is grouped (or coupled) with a third playback device 1210c (FIG. 12C) having a battery that is charged according to a charging scheme 1280c. In some examples, the third playback device 1210c has a battery with a different charge capacity than the battery of the first playback device 1210a. For example, the battery of the first playback device 1210a may have a storage capacity (or alternatively, a target charge level) that is a first percentage (e.g., 10%, 25%, 33%, 50%, 60%, 75%, 80%, 90%, etc.) of the storage capacity of the third playback device 1210c (or vice versa). However, because the devices are configured for group playback, the devices may be configured to play audio while both devices have sufficient battery power remaining. Thus, when the devices are grouped together, the charging scheme 1280c can be adjusted so that the target charge level of the third playback device 1210c is approximately a first percentage of the total storage capacity of the third playback device's 1210c battery. In some examples, the charging scheme 1280c is updated to charge the battery of the third playback device 1210c based on a predictive model of power consumption so that the batteries of both devices reach a minimum threshold charge (e.g., 0% remaining, 1% remaining, 5% remaining, 10% remaining, 15% remaining, etc.) substantially simultaneously during playback. In some examples, the individual charging schemes 1280a and 1280c are also adjusted to account for differences in standby power consumption between the devices. Adjusting the charging scheme 1280c as described above can allow for a lower target charge level than would be typical if the third playback device 1210c were not grouped, which may beneficially result in a slower charging rate and therefore potentially greater battery life. In some examples, when the devices are ungrouped, the charging scheme 1280c may revert to more typical charging target levels and patterns.

[0145] In some examples, the first playback device 1210a and the second playback device 1210b are grouped with a third playback device 1210c (FIG. 12D). In one scenario, for example, the battery of the third playback device 1210c has a first percentage (e.g., 20%, 30%, 50%, 75%, 90%, 100%, etc.) of storage capacity that is different (e.g., larger) than the batteries of the other devices. Thus, some tasks / responsibilities that typically consume a non-negligible amount of power, such as voice command detection, group coordination, audio processing and calibration (e.g., Trueplay), and algorithmic media content generation, can be shifted to the third playback device 1210c to take advantage of its larger battery storage capacity. In this scenario, the charging schemes 1280c, 1280d, and 1280f are adjusted so that the batteries of the three devices during group playback are expected to reach a predetermined minimum value substantially simultaneously.

[0146] In some examples, the charging scheme 1280f may be adjusted to compensate for the additional responsibilities. For example, assuming all three devices had the same responsibilities, the media playback system may determine the target charge levels of the first playback device 1210a and the second playback device 1210b to be approximately a first percentage (e.g., 95%) and a second percentage (e.g., 95%), respectively, and determine the target charge level of the third playback device 1210c to be approximately 30% (representing the percentage of the storage capacity of the battery of the third playback device 1210c relative to either the first playback device 1210a or the second playback device 1210b). The charging scheme 1280f may be adjusted by one or more additional offsets, including, for example, a first offset and a second offset.

[0147] In some examples, the charging scheme is adjusted by a predictive synthesis offset that considers one or more additional parameters other than simply predicted power consumption. In some cases, a “weaker” group member with less storage capacity and / or bass capability may offload processing of low-frequency content to a “more capable” group member (or group coordinator) with more storage capacity and / or bass capability. Thus, the charging scheme 1280f may be adjusted to account for (a) the additional power consumption by the more capable group member(s) and (b) the longer predicted battery operating time of the less capable group member (due to no longer needing to generate certain bass frequencies). In some examples, the first playback device 1210a and the second playback device 1210b offload processing of low-frequency signals below a crossover frequency (e.g., 100 Hz, 125 Hz, 200 Hz, 250 Hz, 300 Hz) to the third playback device 1210c, potentially extending the expected battery operating time (e.g., 15 minutes, 30 minutes, 45 minutes, 60 minutes, 120 minutes, etc.) of the first playback device 1210a and the second playback device 1210b. Thus, the charging scheme 1280c can be adjusted by a composite offset that takes into account several parameters, including (a) the expected additional power consumption required to output the low frequencies of the other devices, and (b) the expected additional operating time of the other devices. In this scenario, the charging scheme 1280c may have a first target charge level (e.g., 35%, 40%, 50%, 75%, 80%) that is adjusted by a predicted composite offset that represents the additional power consumption required (as a percentage of the total storage capacity of the battery of the third playback device 1210c) plus the additional operating time(s) of the other devices. In some examples, the predicted composite offset may be affected by the type of media content being played. For example, spoken word content (such as podcasts, talk radio, sports, social audio, etc.) is expected to have significantly less low-frequency content than audio associated with music and / or video content.

[0148] 13A-13D illustrate example device playback sessions according to the disclosed technology. Referring together to FIGS. 13A-13D, in some examples, when the remaining charge level of the battery of the first playback device 1210a (when being charged due to an external power source) falls below a predetermined minimum threshold percentage (e.g., 1%, 5%, 10%, 15%), one or more nearby playback devices can be detected and the playback session 1390a can be transitioned thereto, either automatically or via manual input. For example, the presence of a neighboring playback device 1310a (FIG. 13A) can be detected within a threshold distance (e.g., 1 m, 3 m, 5 m, 10 m), and the playback session 1390a can be transitioned or "swapped" thereto from the first playback device 1210a accordingly.

[0149] In some examples, for example, a playback device having an ongoing playback session may maintain or access playback session data that defines and / or identifies the playback session. The playback session data may include data representing the source of the audio content (e.g., a URI or URL indicating the location of the audio content) and an offset indicating the location within the audio content where playback should begin. The offset may be defined as a time (e.g., in milliseconds) or a number of samples from the beginning of the audio track, as another example. In an exemplary implementation, the offset may be set to a playback position within the audio content of the current playback position to allow time for the target device to begin buffering the audio content. The source playback device then stops playing the audio content at the offset, and the target playback device begins playing the audio content at the offset. The playback session data may include data representing the source of the audio content (e.g., a URI or URL indicating the location of the audio content) and an offset indicating the location within the audio content where playback should begin. The offset may be defined as a time (e.g., in milliseconds) or a number of samples from the beginning of the audio track, as another example. Additional details regarding swapping or transitioning playback sessions between playback devices are described, for example, in U.S. Pat. No. 11,356,777, "Playback Transitions," and U.S. Patent Application No. 16 / 805,182, "Playback Transitions," filed February 28, 2020, each of which is incorporated by reference in its entirety.

[0150] In some examples, the playback device 1310a is a corded audio playback device. In other examples, the playback device 1310a is a portable, high-volume playback device, a wearable device such as headphones or earphones, or a battery-powered portable device such as a smartphone or tablet. Automatically transferring playback from the first playback device 1210a to the playback device 1310a has the advantage of allowing audio playback to continue even if the battery of the first playback device 1210a is close to being completely discharged. In some examples, when the first playback device 1210a is connected to a power source and the battery level reaches a certain threshold percentage (e.g., 25%, 33%, 50%, 75%, 90%, 95%), the system automatically transfers the playback session 1390a back to the first playback device 1210a and stops playback on the playback device 1310a.

[0151] In some examples, rather than transferring the entire playback session to another device, the system can allocate a first portion 1390b ​​of the playback session of a first playback device 1390 to another playback device 1310b (e.g., a subwoofer), as shown in FIG. 13B. For example, the first portion 1390b ​​can include a portion of the playback session's frequency spectrum below a first crossover frequency (e.g., 100 Hz, 125 Hz, 200 Hz, 250 Hz). Allocating the first portion of the frequency spectrum to playback device 1310b so that the first playback device 1210a plays audio above the first crossover frequency can reduce the amount of power consumed during playback and therefore extend battery life due to less frequent charging and fewer charge cycles.

[0152] In some examples, a second portion 1390c (FIG. 13C) of the playback session of the first playback device 1210a is assigned to playback device 1310c for playback, and a third portion 1390d of the playback session is assigned to playback device 1310b. The second portion 1390c may include audio that is different from (e.g., lower than) the first crossover frequency and higher than a second crossover frequency (e.g., 100 Hz, 125 Hz, 200 Hz, 250 Hz), and the third portion 1390d may include audio that is lower than the second crossover frequency. In some examples, playback device 1310c comprises an out-loud device (such as a soundbar or all-in-one player) that has better bass capabilities than the first playback device 1210a and can be plugged into a wall power source (or has a larger battery capacity than the first playback device 1210a). In this scenario, a crossover frequency lower than the first crossover frequency is selected because of its higher bass capability and ability to consume more power (relative to the first playback device 1210a). In some examples, even when the first playback device 1210a is connected to a power source or has a significant amount of charge remaining (e.g., greater than 50%), the first playback device 1210a does not play itself but continues to receive audio from an audio source, e.g., via Bluetooth or other IEEE 802.15-compatible protocol, a physical line-in, etc., and transmit the audio to playback devices 1310b and 1310c (and / or other devices). By allocating the second portion 1390c and the third portion 1390d of the playback session to corded devices, the charge rate required to charge the first playback device 1210a, even while it is charging, can be minimized, potentially extending its battery life. Rather than assigning the second portion 1390c and the third portion 1390d to individual devices, in some examples (FIG. 13D), the complete playback session 1390a is assigned to one or more other devices, such as playback device 1310c, which then relinquishes the third portion 1390d (or another portion) of the playback session to playback device 1310b.In some examples, the playback device 1310c comprises a wearable device.

[0153] 14A-14C show examples of device charging schemes and / or audio data transmission / relaying according to the disclosed techniques. Referring together to FIGS. 14A-14C, in some examples, the first playback device 1210a can receive power from one or more other devices via a power transmission link and simultaneously transmit and / or receive audio data from the corresponding device(s). The power transmission link may comprise one or more wires (e.g., thin wires), cables (e.g., power cables, data transmission cables such as Ethernet cables, USB cables, etc.), and / or wireless transmission modes such as those described above with respect to FIGS. 7 and 8.

[0154] In some examples, a playback device can receive audio data (or other data, such as video data, control data, timing information, etc.) relayed through other playback devices while simultaneously receiving power from the other playback devices. For example, FIG. 14A shows an example in which a first playback device 1210a may receive audio data 1492a and power via a power transmission link 1495a from a third playback device 1210c. The playback device 1210c may be configured to relay the audio data 1492a via a transmission path (e.g., Bluetooth Low Energy (BLE) or other similar low-energy personal area network (PAN)) that requires less power at the first playback device 1210a compared to a conventional transmission path (e.g., via WiFi over a local area network (LAN)). Accordingly, the charging scheme of the first playback device 1210a may be adjusted to modify one or more parameters (e.g., charging rate, target charging level, etc.), potentially resulting in a lower charging rate and therefore extended battery life.

[0155] In some examples, one playback device may relay audio data and transmit power to multiple other playback devices. For example, FIG. 14C shows an example in which playback device 1410b relays audio data 1492c (e.g., a left rear surround channel) and audio data 1492d (e.g., a right rear surround channel) to first and second playback devices 1210a and 1210b, respectively. Playback device 1410b also transmits power to first and second playback devices 1210a and 1210b via power transmission links 1495c and 1495d, respectively. In some examples, power transmission links 1495c and 1495d are of substantially the same power transmission type (e.g., wireless power transmission, one or more cables, etc.). In other examples, power transmission links 1495c and 1495d are of different types. In particular embodiments, the first playback device 1210a receives power from the playback device 1410b, while the second playback device 1210b receives power from another source (e.g., a wall outlet, another device, energy harvesting, etc.). In some examples, the charging scheme of the first and second playback devices 1210a and 1210b is adjusted based on the coupling zone type (e.g., home theater multi-channel audio such as stereo pair, 5.1, 5.x, 7.1.2, 7.2.4, 9.2.4, 9.4.6, etc.), audio data content, power transmission type, and / or one or more other parameters described above.

[0156] In some examples, a playback device can transmit audio data to another device while simultaneously receiving power from the other device via a power transmission link. For example, FIG. 14B shows an example in which a playback device 1210a receives power from a device 1410a via a power transmission link 1495b (e.g., one or more wires, cables, wireless power transmission modalities) while simultaneously transmitting playback data 1492b to the device 1410a. In the illustrated example of FIG. 14B, the device 1410b comprises a light source. In some examples, the device 1410a comprises a playback device with or without a transducer. In some examples, the device 1410a comprises one or more displays. In some examples, the device 1410a comprises one or more IoT devices or home appliances. In some examples, the device 1410a is a component of and / or integrated into a vehicle (e.g., an automobile, boat, bus, airplane). In some examples, at least one of the first playback device 1210a and / or the device 1410a comprises a wearable device. In operation, the first playback device 1210a receives data 1492b (such as audio content, video content, game content, augmented reality (e.g., virtual, augmented, and / or mixed reality) content, timing information, control data, and / or other suitable data described above) and transmits the data 1492b to the device 1410a. The device 1410a can play the data 1492b while providing power to the first playback device 1210a. In some examples, for example, the first playback device 1210a transmits the data 1492b to the device 1410a for playback (e.g., one or more playback devices) rather than being played by the first playback device 1210a to reduce power consumption in the first playback device 1210a. In some examples, the determination of whether to receive power and / or transmit the data 1492b via the power transmission link 1495b can be based on a charging scheme of the first playback device 1210a.For example, in some examples, when the current charge level of the battery of the first playback device 1210a is around a certain percentage (e.g., 40%, 50%, 60%, 75%, 90%), the first playback device 1210a can stop receiving power over the power transmission link 1495b and / or relaying data 1492b. In some examples, the charging scheme is adjusted based on the detected distance between the first playback device 1210a and the device 1410a.

[0157] In the illustrated examples described above, the devices may be shown as audio playback devices, but in some examples, one or more of the devices may comprise other types of devices, including Internet of Things (IoT) devices such as smartphones, tablets, video display devices (e.g., televisions), sensors, cameras, microphones, thermostats, light sources, smart doorbells, and the like.

[0158] V. Conclusion The above descriptions of wirelessly powered devices, playback devices, control devices, playback zone configurations, and media / audio content sources are merely examples of some of the operating environments in which the features and methods described below may be implemented. Other operating environments and configurations of wirelessly powered systems, media playback systems, playback devices, and network devices not explicitly described herein may also be applicable and suitable for implementing the features and methods.

[0159] The above description discloses various exemplary systems, methods, apparatus, and articles of manufacture that include, among other components, firmware and / or software executing on hardware. It is understood that such examples are merely illustrative and should not be considered limiting. For example, it is intended that any or all of the firmware, hardware, and / or software aspects or components may be embodied exclusively in hardware, exclusively in software, exclusively in firmware, or in any combination of hardware, software, and / or firmware. Thus, the examples provided are not the only ways to implement such systems, methods, apparatus, and / or articles of manufacture.

[0160] Furthermore, references herein to an "embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one example embodiment of the present invention. Appearances of this term in various places throughout this specification do not necessarily all refer to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. As such, the embodiments described herein can be combined with other embodiments, as will be understood, either explicitly or implicitly, by one skilled in the art.

[0161] This specification has been presented broadly in terms of illustrative environments, systems, procedures, steps, logic blocks, processes, and other symbolic representations that directly or indirectly resemble the operation of network-connected data processing devices. These process descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. Many specific details have been set forth to provide a thorough understanding of the present disclosure. However, those skilled in the art will understand that certain embodiments of the present disclosure may be practiced without the specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail to avoid unnecessarily obscuring aspects of the embodiments. Accordingly, the scope of the present disclosure is defined by the appended claims, rather than by the description of the embodiments set forth above.

[0162] If any of the appended claims are read to cover a purely software and / or firmware implementation, then at least one of the elements in at least one example is expressly defined herein to include a tangible, non-transitory medium, such as memory, DVD, CD, Blu-ray, etc., that stores the software and / or firmware.

[0163] The present technology is exemplified, for example, according to various aspects described below. Various examples of aspects of the present technology are described as numbered examples (1, 2, 3, etc.) for convenience. These are provided as examples and are not intended to limit the present technology. It should be noted that any of the subordinate examples can be combined in any combination and arranged into their own independent examples. Other examples can be presented as well.

[0164] Example 1: A media playback system, comprising: a first regenerative device having a first capacitor; a second regenerative device with a second capacitor; one or more computer-readable media; and instructions stored on the media that, when executed by one or more processors of a media playback system, perform the following operational steps: receiving power from a first power source and charging a first capacitor according to a first charging scheme; receiving power from a second power source and charging a second capacitor according to a second charging scheme; receiving an instruction to form a synchronized audio playback group consisting of at least the first playback device and the second playback device; obtaining one or more power parameters associated with the first playback device and / or the second playback device; modifying the first charging scheme based on one or more power parameters after receiving the instruction to form the group; and receiving power from a first power source to charge a first capacitor according to a modified first charging scheme; A media playback system having:

[0165] Example 2: The power parameters are: Charge level of the first capacitor; Charge level of the second capacitor; Age of the first capacitor; Age of the second capacitor; the temperature of the first capacitor; the temperature of the second capacitor; Charging rate of the first charging method; Charging rate of the second charging method; Responsibility for the first playback device; Responsibility for regeneration of the second regeneration device; player capability parameters of the first playback device; player capability parameters of the second playback device; time parameters; 10. The media playback system of any of the preceding examples, including one or more of:

[0166] Example 3: The media playback system of any of the above examples, wherein changing the first charging method includes changing a target charge level of the first capacitor to a charge level that is lower than a maximum charge capacity of the first capacitor.

[0167] Example 4: The media playback system of any of the previous examples, wherein the first playback device includes one or more energy harvesters, and the one or more power parameters include an indication of power received via the one or more energy harvesters.

[0168] Example 5: The media playback system of any of the above examples, further comprising, as an operational step, changing the first charging scheme and / or the second charging scheme such that a playback device having a lower charge level charges at a faster rate than a playback device having a higher charge level.

[0169] Example 6: The media playback system of any of the above examples, further comprising, as an operating step, changing the first charging scheme and / or the second charging scheme such that the first capacitor and the second capacitor reach a threshold charge level substantially simultaneously.

[0170] Example 7: Furthermore, as an action step: synchronously playing audio content via the first playback device and the second playback device; and modifying the playback based on the one or more power parameters to reduce an amount of audio content played through at least the first playback device, the amount of audio content having frequencies below a predetermined threshold frequency; 10. The media playback system of any of the preceding examples, comprising:

[0171] Example 8: The media playback system of any of the above examples, further comprising a third playback device, and further comprising, as an operating step, synchronously playing back, via the third playback device, at least a portion of audio content having a frequency below a predetermined threshold frequency.

[0172] Example 9: Furthermore, as an operation process, receiving an instruction to ungroup the first playback device and the second playback device; restoring the changed first charging method to the first charging method before the change based on receiving a command to ungroup the first playback device and the second playback device; After returning the changed first charging method to the first charging method, receiving power from the first power source and charging the first capacitor according to the first charging method; 10. The media playback system of any of the preceding examples, comprising:

[0173] Example 10: The media playback system of any of the above examples, wherein the first playback device includes a first network interface, and wherein obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device via the first network interface.

[0174] Example 11: The media playback system of any of the above examples, wherein the second playback device includes a second network interface, and wherein obtaining the one or more power parameters comprises transmitting data corresponding to the one or more power parameters associated with the second playback device via a first network interface.

[0175] Example 12: The media playback system of any of the above examples, wherein obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device via a first network interface from a computing device.

[0176] Example 13: The media playback system of any of the above examples, wherein obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device from the second power source via the first network interface.

[0177] Example 14: The media playback system of any of the previous examples, wherein the first power source is the same as the second power source.

[0178] Example 15: The media playback system of any of the previous examples, wherein the first power source is different from the second power source.

[0179] Example 16: A method comprising: receiving power from a first power source and charging a first capacitor of a first playback device according to a first charging method; receiving power from a second power source and charging a second capacitor of the second playback device according to a second charging method; receiving an instruction to form a synchronized audio playback group consisting of at least the first playback device and the second playback device; obtaining one or more power parameters associated with the first playback device and / or the second playback device; modifying the first charging scheme based on one or more power parameters after receiving the instruction to form the group; and receiving power from a first power source to charge a first capacitor according to a modified first charging scheme; A method having the following.

[0180] Example 17: The power parameters are: Charge level of the first capacitor; Charge level of the second capacitor; Age of the first capacitor; Age of the second capacitor; the temperature of the first capacitor; the temperature of the second capacitor; Charging rate of the first charging method; Charging rate of the second charging method; Responsibility for the first playback device; Responsibility for regeneration of the second regeneration device; player capability parameters of the first playback device; player capability parameters of the second playback device; time parameters; The method according to any of the above examples, including one or more of:

[0181] Example 18: The method according to any of the above examples, wherein the step of changing the first charging method includes changing a target charge level of the first capacitor to a charge level that is lower than a maximum charge capacity of the first capacitor.

[0182] Example 19: The method of any of the above examples, wherein the first playback device includes one or more energy harvesters, and the one or more power parameters include an indication of power received via the one or more energy harvesters.

[0183] Example 20: The method of claim 16, further comprising, as an operating step, changing the first charging scheme and / or the second charging scheme so that a playback device having a lower charge level charges at a faster rate than a playback device having a higher charge level.

[0184] Example 21: The method of any of the above examples, further comprising, as an operating step, changing the first charging scheme and / or the second charging scheme such that the first capacitor and the second capacitor reach a threshold charge level substantially simultaneously.

[0185] Example 22: Furthermore, as an action step: synchronously playing audio content via the first playback device and the second playback device; and modifying the playback based on the one or more power parameters to reduce an amount of audio content played through at least the first playback device, the amount of audio content having frequencies below a predetermined threshold frequency; 10. The method of any of the above examples, comprising:

[0186] Example 23: The method of any of the above examples, further comprising a third playback device, and further comprising, as an operating step, synchronously playing back, via the third playback device, at least a portion of audio content having a frequency below a predetermined threshold frequency.

[0187] Example 24: Furthermore, as an operating step, receiving an instruction to ungroup the first playback device and the second playback device; restoring the changed first charging method to the first charging method before the change based on receiving a command to ungroup the first playback device and the second playback device; After returning the changed first charging method to the first charging method, receiving power from the first power source and charging the first capacitor according to the first charging method; 10. The method of any of the above examples, comprising:

[0188] Example 25: The method of any of the above examples, wherein the first playback device includes a first network interface, and wherein obtaining the one or more power parameters includes receiving, via the first network interface, data corresponding to one or more power parameters associated with the second playback device.

[0189] Example 26: The method of any of the above examples, wherein the second playback device includes a second network interface, and wherein obtaining the one or more power parameters comprises transmitting data corresponding to one or more power parameters associated with the second playback device via a first network interface.

[0190] Example 27: The method of any of the above examples, wherein obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device via a first network interface from a computing device.

[0191] Example 28: The method of any of the above examples, wherein obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device from the second power source via the first network interface.

[0192] Example 29: The method of any of the above examples, wherein the first power source is the same as the second power source.

[0193] Example 30: The method of any of the above examples, wherein the first power source is different from the second power source.

[0194] Example 31: One or more computer-readable media having instructions stored thereon that, when executed by one or more processors of a media playback system, perform the following operational steps: receiving power from a first power source and charging a first capacitor according to a first charging scheme; receiving power from a second power source and charging a second capacitor according to a second charging scheme; receiving an instruction to form a synchronized audio playback group consisting of at least a first playback device and a second playback device; obtaining one or more power parameters associated with the first playback device and / or the second playback device; modifying the first charging scheme based on one or more power parameters after receiving the instruction to form the group; and receiving power from a first power source to charge a first capacitor according to a modified first charging scheme; 1. A medium having instructions stored thereon,

[0195] Example 32: The power parameters are: Charge level of the first capacitor; Charge level of the second capacitor; Age of the first capacitor; Age of the second capacitor; the temperature of the first capacitor; the temperature of the second capacitor; Charging rate of the first charging method; Charging rate of the second charging method; Responsibility for the first playback device; Responsibility for regeneration of the second regeneration device; player capability parameters of the first playback device; player capability parameters of the second playback device; time parameters; The medium of any of the above examples, including one or more of:

[0196] Example 33: The medium described in any of the above examples, wherein the step of changing the first charging method includes changing a target charge level of the first capacitor to a charge level that is lower than a maximum charge capacity of the first capacitor.

[0197] Example 34: The medium of any of the above examples, wherein the first playback device includes one or more energy harvesters, and the one or more power parameters include an indication of power received via the one or more energy harvesters.

[0198] Example 35: The medium of any of the above examples, further comprising, as an operational step, a step of changing the first charging scheme and / or the second charging scheme so that a playback device having a lower charge level charges at a faster rate than a playback device having a higher charge level.

[0199] Example 36: The medium described in any of the above examples, further comprising, as an operating step, a step of changing the first charging scheme and / or the second charging scheme so that the first capacitor and the second capacitor reach a threshold charge level substantially simultaneously.

[0200] Example 37: Furthermore, as an action step: synchronously playing audio content via the first playback device and the second playback device; and modifying the playback based on the one or more power parameters to reduce an amount of audio content played through at least the first playback device, the amount of audio content having frequencies below a predetermined threshold frequency; 2. The medium of any of the above examples,

[0201] Example 38: A medium described in any of the above examples, further comprising a third playback device, and further comprising, as an operating step, a step of synchronously playing back at least a portion of audio content having a frequency below a predetermined threshold frequency via the third playback device.

[0202] Example 39: Furthermore, as an operating step, receiving an instruction to ungroup the first playback device and the second playback device; restoring the changed first charging method to the first charging method before the change based on receiving a command to ungroup the first playback device and the second playback device; After returning the changed first charging method to the first charging method, receiving power from the first power source and charging the first capacitor according to the first charging method; 2. The medium of any of the above examples,

[0203] Example 40: The medium of any of the above examples, wherein the first playback device includes a first network interface, and the step of obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device via the first network interface.

[0204] Example 41: The medium of any of the above examples, wherein the second playback device includes a second network interface, and the step of obtaining the one or more power parameters comprises transmitting data corresponding to the one or more power parameters associated with the second playback device via a first network interface.

[0205] Example 42: The medium of any of the above examples, wherein obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device via a first network interface from a computing device.

[0206] Example 43: The medium described in any of the above examples, wherein the step of obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device from the second power source via the first network interface.

[0207] Example 44: The medium of any of the above examples, wherein the first power source is the same as the second power source.

[0208] Example 45: The medium of any of the above examples, wherein the first power source is different from the second power source.

[0209] Example 46: A method, comprising: obtaining one or more power parameters associated with at least one of: a first playback device receiving power for charging a first capacitor of the first playback device according to a first charging scheme; and a second playback device receiving power for charging a second capacitor of the second playback device according to a second charging scheme; modifying at least the first charging scheme based on the one or more power parameters; A method comprising configuring a first playback device to receive power for charging a first capacitor of the first playback device according to a modified first charging scheme.

[0210] Example 47: The method further includes receiving an instruction to form a synchronized audio playback group consisting of at least the first playback device and the second playback device; and after receiving the instruction to form the group, causing the first playback device to receive power based on the changed first charging scheme.

[0211] Example 48: The power parameters are: Charge level of the first capacitor; Charge level of the second capacitor; Age of the first capacitor; Age of the second capacitor; the temperature of the first capacitor; the temperature of the second capacitor; Charging rate of the first charging method; Charging rate of the second charging method; Responsibility for the first playback device; Responsibility for regeneration of the second regeneration device; player capability parameters of the first playback device; player capability parameters of the second playback device; time parameters; The method according to any of the above examples, including one or more of:

[0212] Example 49: The method of any of the above examples, wherein changing the first charging scheme includes changing a target charge level of the first capacitor to a charge level that is lower than a maximum charge capacity of the first capacitor.

[0213] Example 50: A method according to any of the above examples, wherein the first playback device includes one or more energy harvesters, and the one or more power parameters include an indication of power reception via the one or more energy harvesters.

[0214] Example 51: The method of any of the above examples, further comprising changing the first charging scheme and / or the second charging scheme so that a playback device having a lower charge level charges at a faster rate than a playback device having a higher charge level.

[0215] Example 52: The method of any of the above examples, further comprising changing the first charging scheme and / or the second charging scheme such that the first capacitor and the second capacitor reach a threshold charge level substantially simultaneously.

[0216] Example 53: A method as described in any of the above examples, further comprising: synchronously playing audio content through the first playback device and the second playback device; and modifying the playback to reduce the amount of audio content having frequencies below a predetermined threshold frequency played through at least the first playback device based on the one or more power parameters.

[0217] Example 54: The method of any of the above examples, further comprising synchronously playing back at least a portion of the audio content having frequencies below the predetermined threshold frequency via a third playback device.

[0218] Example 55: A method according to any of the above examples, further comprising: receiving an instruction to ungroup the first playback device and the second playback device; and restoring the changed first charging method to the original first charging method based on the received instruction to ungroup the first playback device and the second playback device.

[0219] Example 56: A method according to any of the above examples, wherein the first playback device comprises a first network interface, and the step of obtaining the one or more power parameters includes receiving data corresponding to the one or more power parameters associated with the second playback device via the first network interface.

[0220] Example 57: A method according to any of the above examples, wherein the second playback device includes a second network interface, and the step of obtaining the one or more power parameters includes transmitting data corresponding to the one or more power parameters associated with the second playback device via the first network interface.

[0221] Example 58: A method according to any of the above examples, wherein the step of obtaining the one or more power parameters includes receiving data corresponding to the one or more power parameters associated with the second playback device from the computing device via the first network interface.

[0222] Example 59: The method of any of the above examples, wherein the first capacitor receives power from a first power source and the second capacitor receives power from a second power source.

[0223] Example 60: A method according to any of the above examples, wherein the step of obtaining the one or more power parameters comprises receiving data corresponding to the one or more power parameters associated with the second playback device from the second power source via the first network interface.

[0224] Example 61: The method of any of the above examples, wherein the first power source is the same as the second power source.

[0225] Example 62: The method of any of the above examples, wherein the first power source is different from the second power source.

[0226] Example 63: The method of any of the above examples, wherein the step of causing the capacitor to receive power includes causing the capacitor to receive power via wireless power supply.

[0227] Example 64: The method of any of the above examples, wherein modifying the at least first charging regime includes modifying the at least first charging regime based on at least one of usage history and a predictive model trained to predict required charging levels.

[0228] Example 65: A media playback system, 1. A media playback system comprising: a first playback device comprising a first capacitor; a second playback device comprising a second capacitor; and one or more computer-readable recording media having instructions stored thereon that, when executed by one or more processors of the media playback system, cause the media playback system to perform the method of any one of the above examples.

[0229] Example 66: One or more tangible, non-transitory computer-readable media storing instructions that, when executed by one or more processors of a media playback system, cause at least one device of the media playback system to perform the method of any one of the preceding examples.

Claims

1. A method of charging a capacitor in a media playback system having one or more processors for controlling the following operational steps: receiving power from a first power source and charging a first capacitor of a first playback device according to a first charging method; receiving power from a second power source and charging a second capacitor of a second playback device according to a second charging method; receiving an indication to form a synchronized audio playback group consisting of at least the first playback device and the second playback device; obtaining one or more power parameters associated with at least the first playback device; modifying the first charging scheme based on one or more power parameters after receiving the instruction to form the group; and receiving power from a first power source to charge a first capacitor according to a modified first charging scheme; and employing a first charging scheme and a second charging scheme, and making at least the first charging scheme variable, thereby improving the performance and lifespan of at least a first capacitor.

2. The power parameters are: the charge level of the first capacitor; the charge level of the second capacitor; Age of the first capacitor; Age of the second capacitor; the temperature of the first capacitor; the temperature of the second capacitor; the charging rate of the first charging method; the charging rate of the second charging method; playback responsibility of the first playback device; playback responsibility of the second playback device; player capability parameters of the first playback device; player capability parameters of the second playback device; Time parameters; The method of claim 1 , comprising one or more of:

3. 2. The method of claim 1, wherein the step of changing the first charging method includes changing a target charge level of the first capacitor to a charge level that is lower than a maximum charge capacity of the first capacitor.

4. The method of claim 1 , wherein the first playback device includes one or more energy harvesters, and the one or more power parameters include an indication of power received via the one or more energy harvesters.

5. 10. The method of claim 1, further comprising, as an operating step, modifying at least the first charging scheme so that playback devices having lower charge levels charge at a faster rate than playback devices having higher charge levels.

6. 10. The method of claim 1, further comprising, as an operating step, changing the first charging scheme and / or the second charging scheme such that the first capacitor and the second capacitor reach a threshold charge level substantially simultaneously.

7. Furthermore, the operation steps are as follows: synchronously playing audio content via the first playback device and the second playback device; and modifying the playback of audio content via at least the first playback device based on the one or more power parameters, such that playback of frequencies below a predetermined threshold frequency is reduced; 2. The method of claim 1, comprising:

8. 8. The method of claim 7, further comprising a third playback device, and further comprising, as an operating step, synchronously playing back at least a portion of the audio content having frequencies below a predetermined threshold frequency via the third playback device.

9. Furthermore, as an operation process, receiving an instruction to ungroup the first playback device and the second playback device; restoring the changed first charging method to the first charging method before the change based on receiving a command to ungroup the first playback device and the second playback device; receiving power from the first power source and charging the first capacitor according to the first charging method after returning the changed first charging method to the first charging method; 2. The method of claim 1, comprising:

10. 10. The method of claim 1, wherein the first playback device includes a first network interface, and wherein obtaining the one or more power parameters includes receiving data corresponding to one or more power parameters associated with the second playback device via the first network interface.

11. 11. The method of claim 10, wherein the second playback device includes a second network interface, and wherein obtaining the one or more power parameters comprises transmitting data corresponding to the one or more power parameters associated with the second playback device via a first network interface.

12. 11. The method of claim 10, wherein obtaining the one or more power parameters comprises receiving data corresponding to one or more power parameters associated with the second playback device via a first network interface from a computing device.

13. 11. The method of claim 10, wherein obtaining the one or more power parameters comprises receiving data corresponding to one or more power parameters associated with the second playback device from the second power source via the first network interface.

14. The method of claim 1 , wherein the first power source is the same as the second power source.

15. The method of claim 1 , wherein the first power source is different from the second power source.

16. A media playback system comprising one or more processors, a first playback device having a first capacitor; a second regeneration device having a second capacitor; and one or more computer-readable media having stored thereon instructions that, when executed by the one or more processors, cause the media playback system to perform the method of claim 1.

17. A computer-readable recording medium having recorded thereon a program for causing a computer to execute the method according to claim 1.

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