Event activity detection apparatus and method

Abstract

Acoustic and other activity detection signals are provided herein. The operation of a method can include determining that a microelectromechanical system (MEMS) device is no longer in an initialization state, and receiving a first signal indicative of the MEMS device performing event activity detection. The method can also include receiving one or more event signals, and determining that an event signal of the one or more event signals satisfies a defined event characteristic. The method can also include outputting a second signal including information indicative of event activity detected at the MEMS device being greater than the defined event characteristic.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. nonprovisional patent application serial number 17 / 821548, filed August 23, 2022, entitled “Event Activity Detection sIGNALING”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to the field of sensors, including sensor microphones, and more specifically, to microelectromechanical systems (MEMS) that detect acoustic event activity and perform event activity detection signals. Background Technology

[0004] Activity detection, such as acoustic activity detection and / or other event activity detection, requires the listening device (e.g., acoustic sensors) to react to audio wake-up activity. This can potentially involve significant power consumption, complex systems, and substantial processing time to analyze and quantify the audio content. For example, an acoustic sensor might wake up the processing system simply based on an on / off indication that a sound pressure level event has exceeded a defined level. The processing system must then be fully powered on and collect, process, and perform further processing to analyze and quantify the audio content. Therefore, providing an acoustic sensor that can detect and process audio wake-up activity more quickly, with lower power consumption and less complexity presents a unique challenge. Summary of the Invention

[0005] This application relates to acoustic activity detection signal circuits and / or other types of event activity detection signal circuits for single microphone sensors and / or multiple microphone sensors, as well as other types of sensors. This application also relates to acoustic activity detection methods and / or other types of event activity detection methods for single microphone sensors and / or multiple microphone sensors, as well as other types of sensors.

[0006] This document provides a device including a micro-electromechanical system (MEMS) transducer and circuitry for activity detection. The circuitry may include a first node configured to transmit or receive data associated with a clock signal. The circuitry may also include a second node configured to operate in a first mode during a power-up phase of the device and in a second mode after the power-up phase has completed. The second node is configured to receive a signal that causes the device to perform activity detection based on activity determination.

[0007] In one example, the clock signal is below the normal operating frequency or has stopped at the first node. In another example, depending on some implementations, the circuit may include a third node configured to transmit one or more acoustic signals.

[0008] In some implementations, the second node is configured to receive a signal that causes the device to perform acoustic activity detection. For example, the second node may perform acoustic activity detection based on a determination that the clock signal at the first node has stopped or is operating at a frequency below normal operating frequency.

[0009] According to some implementations, when operating in the second mode, the second node is configured as a communication interface for activity detection. In addition to these implementations, the communication interface includes at least one of a transmitted signal or a received signal associated with acoustic activity detection. In some implementations, the communication interface is a single-wire communication interface or operates as a single-wire communication interface. The communication interface can facilitate write and read access to internal registers associated with the MEMS transducer. Those skilled in the art will understand that writing to the internal registers may include changing the functional mode of operation. According to some implementations, the communication interface is a serial interface.

[0010] In one example, the MEMS transducer includes a MEMS acoustic sensor that receives an acoustic signal comprising an acoustic signal frequency. According to another example, the second node is a MEMS transducer selector pin. Depending on some implementations, the device may include a serial interface for communicating with external devices. Furthermore, according to some embodiments, the voltage at the second node indicates the device's location within the device system.

[0011] According to some implementations, activity detection is based on acoustic activity. Acoustic activity may include at least one of voice, keywords, collisions, explosions, gunshots, broken glass, unsafe sound levels, built-in self-test failure, over-temperature threshold, and under-temperature threshold.

[0012] According to some implementations, the signal is a first received signal. In addition to these implementations, the device also includes a light sensor. Furthermore, when operating in a second mode, the second node is configured to send a transmit signal when a second signal from the light sensor exceeds a threshold.

[0013] In some implementations, the signal is a first received signal, and the device further includes a humidity sensor. In addition to these implementations, when operating in a second mode, the second node is configured to send a transmit signal when a second signal from the humidity sensor exceeds a threshold.

[0014] A method is also provided, comprising determining that a microelectromechanical system (MEMS) device is no longer in an initialized state. The method further includes receiving a first signal instructing the MEMS device to perform acoustic activity detection, and receiving one or more acoustic signals. Furthermore, the method includes determining that one of the one or more acoustic signals satisfies a defined acoustic characteristic. The method may also include outputting a second signal comprising information indicating that the acoustic activity detection at the MEMS device is greater than the defined acoustic characteristic. In one example, the defined acoustic characteristic may include spectral signal level or signal power in a given spectrum.

[0015] According to some implementations, the method may include determining that the MEMS device is in a powered-on state and receiving a selection after determining the initialization state. According to some implementations, the method may include communicating with an external device via a communication interface. The communication interface may be a serial interface.

[0016] According to some implementations, receiving the first signal may include receiving the first signal at the selector node. According to some implementations, outputting the second signal may include outputting the second signal at the selector node.

[0017] The method may further include stopping the external clock or reducing the frequency after receiving the first signal. Alternatively or additionally, the method may include receiving defined acoustic characteristics during the initialization state.

[0018] According to some implementations, the acoustic signal is a first acoustic signal, and the method may include, after a delay prior to receiving a clock signal, a second determination that a second acoustic signal of one or more acoustic signals satisfies defined acoustic characteristics. In addition to these implementations, the method may also include, after the second determination, changing the defined acoustic characteristics.

[0019] Furthermore, depending on some implementations, the method may include receiving a clock start signal or a clock at its normal operating frequency. Acoustic activity detection may be interrupted upon or after receiving the clock start signal. Attached Figure Description

[0020] Various non-limiting embodiments are further described with reference to the accompanying drawings, in which:

[0021] Figure 1 Exemplary non-limiting devices according to one or more embodiments described herein are shown;

[0022] Figure 2 Exemplary non-limiting protocols for read and write operations according to one or more embodiments described herein are illustrated;

[0023] Figure 3A flowchart is shown of an exemplary non-limiting computer implementation method for detecting acoustic activity signals using a shared selector node according to one or more embodiments described herein;

[0024] Figure 4 A flowchart is shown of an exemplary non-limiting computer implementation method for acoustic activity detection signals using a shared selector output and a relative threshold, according to one or more embodiments described herein;

[0025] Figure 5 Another exemplary non-limiting device according to one or more embodiments described herein is shown;

[0026] Figure 6 Exemplary non-limiting microelectromechanical system (MEMS) sensor circuits for device identification and detection of two or more sensors via a single-wire communication interface, according to one or more embodiments described herein; and

[0027] Figure 7 A flowchart is shown of an exemplary non-limiting computer implementation method for an event activity detection signal using a shared selector output and a relative threshold, according to one or more embodiments described herein. Detailed Implementation

[0028] One or more embodiments will be described more fully below with reference to the accompanying drawings, in which exemplary embodiments are illustrated. In the following description, numerous specific details are set forth for purposes of explanation in order to provide a thorough understanding of the various embodiments.

[0029] Acoustic sensing is used to access the environment of events of interest (e.g., human voice, activation of a smoke detector, glass breaking, gunshot, or other acoustic events). For example, acoustic sensing may be used for security or other purposes, requiring monitoring of the environment for one or more events of interest. In most implementations, the acoustic events of interest occur infrequently. Therefore, existing systems employ always-on (e.g., always-listening) acoustic wake-up detectors to detect one-off events (e.g., glass breaking) and / or critical events. Furthermore, existing systems require a significant (sometimes very high) power input to react to audio wake-up activity, are complex, and require time to analyze and quantify the audio content.

[0030] Existing acoustic activity detection systems or circuits may include a microphone and a voice processor with embedded acoustic activity detection circuitry, the voice processor potentially including embedded digital signal processing (DSP) capabilities. Operation of such systems is limited to being activated only by an "on" and / or "off" indication based on a sound pressure level event exceeding a specified decibel sound pressure level (dB SPL). Once this indication is received, the system is fully powered on and collects and processes a set of audio data to extract frequency and amplitude details. This data must then be analyzed to determine the next course of action. For example, the data is processed by a voice processor or other type of acoustic analyzer, and a Fast Fourier Transform (FFT) is performed on the content, which is then subjected to a series of algorithms to classify the events that have occurred. This data processing can be power-intensive and time-consuming.

[0031] One or more embodiments provided herein facilitate low-power acoustic (and / or other event) activity detection signal circuitry having a single output configured as a single-wire communication interface. A method for low-power acoustic (and / or other event) activity detection signals utilizing the output as a single-wire communication interface is also provided.

[0032] First refer to Figure 1 This document illustrates an exemplary non-limiting device 100 according to one or more embodiments described herein. According to some implementations, the device may be a digital microelectromechanical system (MEMS) device, a MEMS microphone, or another type of sensor device. The various embodiments discussed herein relate to acoustic activity detection. As described herein, acoustic activity detection is an ultra-low-power edge processing feature where a microphone (e.g., a MEMS microphone) monitors acoustic activity (e.g., an event of interest) in the environment and wakes up a system-on-chip (SoC) or application processor upon detection of acoustic activity.

[0033] It is important to note that acoustic signal detection is only one type of event that can be detected. Conversely, other events can also be detected while sharing similar detection configurations and signal processes described herein. These other events include, but are not limited to, intelligent acoustic events such as Voice Activity Detection (VAD), Keyword Spotting (KWS), and Automatic Speech Recognition (ASR). For example, intelligent acoustic events may include, but are not limited to, speech, keywords, collisions, explosions, gunshots, broken glass, etc.

[0034] Other detectable events are unsafe sound levels. For example, levels exceeding the defined dB SPL level (e.g., exceeding 130 dB SPL) can be considered unsafe and monitored as described herein.

[0035] Another possibility is a failure of the Built-In Self-Test (BIST). For example, the BIST can be used to determine various conditions, including the health and / or condition of the microphone and the health and / or condition of other components.

[0036] Other events may also be related to temperature conditions. For example, over-temperature thresholds and / or under-temperature thresholds can trigger another event detection. This detection can be performed, for example, by an internal temperature sensor.

[0037] In another example, humidity and / or moisture can trigger another event. Humidity and / or moisture can be detected, for example, by an internal humidity sensor. Additionally, another event could be pressure, which, for example, can be monitored by an internal pressure sensor. Ambient light conditions could be another triggering event, which can be evaluated using an internal light sensor.

[0038] Typically, when an event is detected, an event detection signal is sent to an external host processor or SoC. The host processor or SoC then processes the event-related details and / or receives instructions based on the event detection. For event detection, the microphone should be at the lowest possible power level, as it needs to be "always on" to detect events. In some cases, as much circuitry and components as possible can be powered off or disabled during microphone functionality, and only (or almost only) activity detection is active. The occurrence of the detection needs to be communicated during or after detection. Therefore, this paper provides a signaling method for performing communication with an external host processor, SoC, and / or another receiving component.

[0039] Continue to refer to Figure 1 Device 100 may include a MEMS transducer and circuitry for activity detection. Sensor 102 may include a digital MEMS transducer 104 and circuitry for processing one or more acoustic signals.

[0040] Device 100 can be coupled to signal line 106 via selector node 108. Selector node 108 may also be referred to as selector output, left / right (L / R) input, MEMS transducer selector, etc. In some implementations, selector node 108 may be a pin. Selector node 108 can be used for communication between one or more MEMS sensors in the system and multiple MEMS sensors (e.g., a package including digital MEMS acoustic sensor 102), such as communication with controller 110. According to some embodiments, controller 110 may be an external controller. However, in some implementations, a chip or SoC may include controller 110 and digital MEMS acoustic sensor 102.

[0041] Device 100 may include an analog-to-digital converter (ADC) 112 coupled to a pulse density modulator (PDM) 114. The PDM modulator 114 receives an external clock (CLK 116) signal and provides a digital data (DATA 118) output signal to device 100.

[0042] Device 100 may also include a channel selection component (not shown) coupled to a control interface component (not shown) at a control pin (e.g., the L / R selection pin of device 100) including selector node 108. In some implementations, device 100 may include a channel selection component coupled to V. DD 120 nodes or pins and GND 122 nodes or pins power management components (not shown).

[0043] More specifically, device 100 may be limited to defined inputs / outputs (e.g., defined pins) required for operation. Such inputs / outputs include powering an output interface for audio streaming data transmission. Left and right (L / R) pins, referred to herein as selector nodes or selector inputs / outputs, are also included on the digital MEMS sensor for selecting the left or right microphone in a two-microphone system.

[0044] Typically, the selector output (L / R pin) is used for communication during the testing process. In some cases, the end user can use the selector output for configuration. As described in this article, the selector input, previously limited to initial setup functions, is being used as a multi-functional interface to also signal acoustic activity detection events. By utilizing existing selector inputs, standard interfaces for digital MEMS sensors can be leveraged, which can provide efficiency in deployment and implementation.

[0045] Note that in Figure 1In this embodiment, the THSEL and WAKE pins are not included in device 100. For example, as shown, the THSEL and WAKE pins included on other digital MEMS sensors have been removed. Alternatively, the THSEL and WAKE pins are not included in the device during manufacturing (e.g., they are not required). By removing (or omitting) the THSEL and WAKE pins, device 100 is a five-input / output (e.g., pin) configuration. This configuration includes selector node 108, CLK 116 output, DATA 118 output, V... DD 120 nodes and GND 122 nodes.

[0046] As described herein, selector node 108 is used to implement the functions previously implemented by the THSEL and WAKE pins, allowing selector node 108 to share the first two functions previously used for polarity detection. It is worth noting that polarity detection is only valid during power-on. Therefore, according to one implementation, upon the first initial power-on during chip startup, selector node 108 reads the configuration of its internal registers and the state of the left and right states. The left and right states are retained during or after the first initial power-on, and selector node 108 has no further functionality for the remainder of the operation. Therefore, selector node 108 can be used as a communication interface for event activity detection as described herein.

[0047] According to one implementation, selector node 108 is used as a communication interface to facilitate the configuration of acoustic activity detection and / or other event activity detection. Furthermore, acoustic activity detection and / or other event activity detection are configured and initiated using selector node 108 via an activity detection initiation command. Therefore, during acoustic activity mode and / or other event activity mode, selector node 108 is used as an input / output. When an event is detected, an output signal notification of this event is sent to other components via selector node 108.

[0048] Figure 2 Exemplary non-limiting protocols for read and write operations according to one or more embodiments described herein are illustrated. For brevity, repeated descriptions of similar elements employed in other embodiments described herein are omitted.

[0049] Figure 2The diagram illustrates a single write operation 200, which includes device address 202, register address 204, and register data 206, without requiring or needing a signal to acknowledge (ACK) the reception of the data. In this embodiment, "S" represents the "start" bit, and "P" represents the stop bit. According to one implementation, for example, the "start" bit and / or the "stop" bit can be generated by an external controller defined by predefined control symbols. Device address 202 can be set to a default value (e.g., 7'h28) and / or can be changed to accommodate any of a variety of numbers and / or types of MEMS sensors. It is noteworthy that the "stop" control symbol can appear anywhere during the protocol. Therefore, whenever a "stop" control symbol is detected or determined, the MEMS sensor can revert to a reset state to await a new "start" control system.

[0050] In this example, one pin (e.g., selector node 108) is used for communication with the event detection trigger. The selector output is configured for OWCI. OWCI is a bidirectional, single-wire communication interface. OWCI is a serial link that enables devices or sensors to communicate over a single wire (e.g., a node, a pin). OWCI can be used to perform write operations if data needs to be written to registers in the microphone. Therefore, the host processor can send communication to the MEMS sensor to perform initial setup or calibration. Writing to registers is known as single-wire communication. The OWCI process refers to the host processor writing to the microphone register through this single node. Therefore, OWCI is a read / write access to internal registers.

[0051] Upon receiving an indication or command to start event detection (e.g., received as input on the OWCI), or afterward, active event detection (e.g., AAD feature) 208 is enabled. Detection mode is initiated when or after the external clock stops, as shown in 210 (e.g., via CLK 116 output). Acoustic activity detection is enabled when or after the external clock stops or the clock frequency falls below the normal operating frequency, after which detection can proceed, as shown in 212. Based on the detection of defined events, output data indicating the occurrence of the detected event is sent via selector node 108. Event detection can be stopped or interrupted upon receiving a clock start signal or upon the clock frequency returning to the normal operating frequency.

[0052] Referring to various flowcharts will provide a better understanding of the methods that can be implemented according to the disclosed subject matter. While these methods are shown and described as a series of blocks for the sake of simplicity, it should be understood and recognized that the disclosed aspects are not limited by the number or order of blocks, as some blocks may appear in different orders and / or substantially simultaneously with other blocks shown and described herein. Furthermore, not all shown blocks need to implement the disclosed methods. It should be understood that the functionality associated with a block can be implemented by software, hardware, a combination thereof, or any other suitable means (e.g., devices, systems, processes, components, etc.). Moreover, it should be further understood that the disclosed methods can be stored on an article of art to facilitate the transport and transfer of these methods to various devices. Those skilled in the art will understand and recognize that these methods can alternatively be represented as a series of interrelated states or events, such as in a state diagram.

[0053] Figure 3 A flowchart is shown of an exemplary non-limiting computer implementation method 300 for detecting acoustic activity signals using a shared selector node, according to one or more embodiments described herein. The computer implementation method 300 can be implemented via circuitry (e.g., device 100, MEMS microphone, system including processor, temperature sensor, humidity sensor, pressure sensor, light sensor, etc.).

[0054] The computer implementation method 300 begins with sensor initialization. To initialize the sensor, at 302 of the computer implementation method 300, the sensor is powered on and a CLK input is provided (e.g., received at a digital MEMS microphone, device, or other sensor). For example, a one-time programmable (OTP) memory is read and the microphone (MIC) is configured. The sensor power-on and CLK input can be provided during IDLE mode.

[0055] At 304, the selector output (e.g., selector node 108) is configured as a one-wire communication interface (OWCI). Therefore, during initial power-up, the selector node can read the configuration of its internal registers and read the state of the selector node (e.g., the L / R pin), for example, for polarity detection. After polarity detection (e.g., after initial power-up), the polarity state is retained, and the selector output can be used for other functions, as described herein (e.g., as OWCI).

[0056] At 306, the host processor sets the AAD parameters. For example, the AAD parameters can be received at the digital MEMS sensor. Alternatively, the AAD mode can be initialized on the OWCI. At 308, CLK stops, and the internal oscillator (OSC) times the MIC. At 310, SEL is set to output "low". Activity detection is activated at this time (e.g., when or after the clock stops).

[0057] At 312, the acoustic signal is received and processed by the AAD. At 314, based on the AAD's determination that the acoustic signal meets a detection threshold (e.g., exceeds the detection threshold), the SEL output is driven "high" for at least a short period of time. For example, the various "thresholds" discussed herein can be defined as simple amplitude values, moving averages, or root mean square (RMS) values. Alternatively, if the AAD determines that the acoustic signal does not meet the detection threshold, the digital MEMS sensor ignores this signal and continues monitoring the environment.

[0058] At 316, CLK is activated when the host processor detects a change in SEL. After the CLK signal is detected at 318, the SEL output is pulled high, and AAD mode stops. Furthermore, MIC mode is set by the CLK frequency, and SEL is configured to OWCI. At this point, the MIC is ready to receive commands from the host processor.

[0059] Figure 4 A flowchart is shown of an exemplary non-limiting computer implementation method 400 for acoustic activity detection signals using a shared selector output and a relative threshold, according to one or more embodiments described herein. The computer implementation method 400 is configured to operate without a host processor (as opposed to...). Figure 3 Compared to the computer implementation method 300).

[0060] The computer implementation method 400 begins with sensor initialization. To initialize the sensor, at 402 of the computer implementation method 400, the sensor is powered on and a CLK input is provided (e.g., received at a digital MEMS sensor). For example, a one-time programmable (OTP) memory is read, and a microphone (MIC) is configured. The power-on of the sensor and the provision of the CLK input can be performed during IDLE mode.

[0061] At 404, the selector output (e.g., selector node 108) is configured as a single-wire communication interface (OWCI). Therefore, during initial power-up, the selector node can read the configuration of its internal registers and read the state of the selector node (e.g., the L / R pin), for example, for polarity detection. After polarity detection (e.g., after initial power-up), the polarity state is retained, and the selector node can be used for other functions as described herein (e.g., as OWCI).

[0062] At 406, the host processor sets the AAD parameters. For example, the AAD parameters can be received at a digital MEMS sensor. Additionally, the AAD mode can be initialized on the OWCI in "relative threshold mode". At 408, CLK stops receiving signals below the normal operating frequency, and the internal oscillator (OSC) times the MIC. At 410, the AAD threshold is set based on one or more AAD parameters. Furthermore, SEL is set to output "low".

[0063] An acoustic signal is received at 412 and processed by the AAD. At 414, it is determined whether the acoustic signal exceeds a detection threshold. For example, this determination can be made after a delay. Furthermore, the SEL output is driven "high". Based on the determination that the acoustic signal meets the detection threshold (e.g., reaches or exceeds the detection threshold), the AAD threshold is increased by a defined increment. Alternatively, if it is determined that the acoustic signal fails to meet the detection threshold (e.g., is less than the detection threshold), the AAD threshold is decreased by a defined decrement. According to some implementations, the defined increment and the defined decrement are different values, the same value, or a combination thereof. Furthermore, the defined increment and / or the defined decrement can be configured.

[0064] The new value of the AAD threshold is stored in an internal register. Furthermore, the AAD threshold delay can be set by the OTP, OWCI registers, or as a function of the AAD threshold.

[0065] At 416, when the host processor detects a change in SEL, it can determine whether to process the event. Furthermore, when or after the CLK signal is detected at 418, the SEL output is "pulled high," and AAD mode stops. MIC mode is set by the CLK frequency, and SEL is configured to OWCI. At this time, the MIC is ready to receive instructions from the host processor.

[0066] Figure 5 Another exemplary non-limiting device 500 according to one or more embodiments described herein is shown. For the sake of brevity, repeated descriptions of similar elements used in other embodiments described herein are omitted.

[0067] Equipment 500 is similar to Figure 1Device 100. However, in the configuration of device 500, the THSEL pin and WAKE pin are replaced by communication interface 502. For example, communication interface 502 can be an I2C interface, an I3C interface, a serial peripheral interface (SPI), etc.

[0068] Communication interface 502 can be used to configure microphone and / or AAD functionality. In another example, communication interface 502 can be used to configure another type of sensor and / or another event detection function.

[0069] Selector node 108 can share these functions. For example, as discussed, selector node 108 (e.g., the L / R pin) can be used for polarity detection during power-up. After power-up, selector node 108 can share functions for event detection. For example, during production testing and factory debugging, selector node 108 can be configured for OWCI. Furthermore, selector node 108 configured for OWCI communication can facilitate output based on event detection events (e.g., "wake-up") and facilitate signaling to the host processor in event detection mode.

[0070] In a specific example, device 500 can measure an optical signal using a light sensor within the microphone package and determine whether the optical signal exceeds a threshold light signal threshold. Upon determining that the optical signal exceeds the threshold light signal threshold, or subsequently, a signal is sent to the host processor via communication interface 502 (e.g., an I2C interface). For example, the “threshold” can be defined as a simple amplitude value, a moving average, or a moving RMS value. Further details relating to the implementation of the optical signal can be found in U.S. Patent Application No. 17 / 174890, filed February 12, 2021, entitled “Optical Interference Detection in MEMS Microphones,” the entire contents of which are expressly incorporated herein by reference.

[0071] Figure 6 An exemplary non-limiting MEMS sensor circuit 600 according to one or more embodiments described herein is shown for device identification and detection of two or more sensors via a single-wire communication interface.

[0072] As shown in the figure, the MEMS sensor circuit 600 includes two or more microphones with corresponding selector (sel) inputs / outputs (e.g., SEL pins), shown as a first microphone selector (MIC1 sel 602), a second microphone selector (MIC2 sel 604), a third microphone selector (MIC3 sel 606), and a fourth microphone selector (MIC4 sel 608). During initialization, each microphone can provide a current (I) to the SEL pin after power-on, and the OTP reads it within a defined time period. After a defined delay, the voltage at the SEL input is measured while Io is still provided.

[0073] Voltage measurements are digitized by multiplying the current by the increment of the resistor (I*R). Each I*R measurement unit directly provides a microphone identifier or ID number. After a defined delay, the SEL pin is configured as OWCI 610. Once complete, Io current and MIC ID detection are disabled (e.g., turned off).

[0074] Therefore, multiple microphones or other sensors can share the same communication bus, while each sensor is individually identifiable. For example, the dimensions of each resistor (e.g., R, R / 2, R / 3, R / N) are used to provide an internal identification number for each microphone (e.g., MIC1 sel 602, MIC2 sel 604, MIC3 sel 606, MIC4 sel 608). The microphones use this internal identification number to communicate with the host processor.

[0075] In one example, individual resistors can be weighted according to a program that allows each microphone (during power-up) to be programmed to output a fixed amount of current from a pin (e.g., selector node 108). Resistors of different sizes or weightings increase the voltage on each microphone pin differently, and these voltages are converted into unique identifiers by an internal analog-to-digital converter. After all microphones have been powered on and configured, a corresponding identifier is assigned, enabling the host processor to communicate individually with each microphone. In this implementation, selector node 108 performs identification rather than polarity detection during power-up.

[0076] Figure 7 A flowchart is shown of an exemplary non-limiting computer implementation method 700 for using a shared selector output and a relative threshold for an event activity detection signal according to one or more embodiments described herein.

[0077] The computer implementation method 700 begins at 702, determining that the microelectromechanical system (MEMS) device is no longer in an initialized state. When or after the device is no longer in an initialized state, the selector node can be used as the single-wire communication interface described herein.

[0078] At 704, a first signal instructing the MEMS device to perform event activity detection can be received. According to one implementation, the first signal can be received at the selector node. In some implementations, the external clock is stopped after the first signal is received. In other implementations, the clock frequency is lower than the normal operating frequency after the first signal is received. Upon or after receiving the first signal, the MEMS device enters a detection state to detect defined events. For example, the defined events could be acoustic detection, smart acoustic event detection, unsafe sound level detection, BIST fault detection, temperature detection, humidity detection, moisture detection, pressure detection, light detection, etc.

[0079] At point 706, one or more signals associated with the event being detected are received. These signals are analyzed, and at point 708, it can be determined that one of the one or more event signals associated with the event satisfies the defined event characteristics. The defined event characteristics can be received during the initialization state.

[0080] For example, for light detection, a defined event characteristic could be that the light intensity is higher (or lower) than a defined threshold light level, the duration of received light is longer (or shorter) than a defined light duration, and so on. In another example, for humidity and / or moisture detection, a defined event characteristic might be that the detected amount of humidity or moisture is greater than (or less) than a defined humidity or moisture threshold. For pressure detection, a defined event characteristic could be a threshold amount of pressure, or the duration of a defined pressure amount. For temperature detection, a defined event characteristic could be a defined temperature and a detection temperature higher (or lower) than that defined temperature, which would trigger an event.

[0081] Based on the determination at 708, at 710, a second signal is output, which includes information indicating that the event activity detected at the MEMS device is greater than a defined event characteristic. In the example of event activity detection, the defined event characteristic may be a spectral signal level. Outputting the second signal may include outputting the second signal at a selector node.

[0082] In some implementations, the computer-implemented method 700 may include determining that the MEMS device is in a powered-on state and receiving a selection after determining the initialization state. Alternatively or additionally, the computer-implemented method 700 may include communicating with an external device via a communication interface. In one example, the communication interface may be a serial interface.

[0083] In some implementations, the computer implementation method 700 may include, after a delay prior to receiving the clock signal, a second determination that one or more event signals satisfy a defined event characteristic. In addition to these implementations, after the second determination, the computer implementation method may include changing the defined event characteristic.

[0084] Furthermore, the computer implementation method 700 may include receiving a clock start signal. Based on the receipt of the clock start signal, event activity detection may be interrupted.

[0085] Throughout this specification, the phrase "an embodiment" or "one embodiment" means that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment. Therefore, the phrases "in one embodiment," "in one aspect," or "in one embodiment" appearing in various places in this specification do not necessarily refer to the same embodiment. Furthermore, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner.

[0086] Furthermore, the terms “example” and “exemplary” as used herein mean as an instance or illustration. Any embodiment or design described herein as “example” or “exemplary” is not necessarily to be construed as superior to other embodiments or designs. Rather, the use of the terms “example” or “exemplary” is intended to present concepts in a specific manner. The term “or” as used in this application is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise stated or the context clearly indicates, “X uses A or B” is intended to mean any natural inclusive arrangement. That is, if X uses A; X uses B; or X uses both A and B, then in any of the foregoing, “X uses A or B” holds true. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be interpreted as “one or more” unless otherwise stated or clearly indicated from the context as a singular form.

[0087] Furthermore, various embodiments can be implemented as methods, apparatus, or articles of art for producing software, firmware, hardware, or any combination thereof using standard programming and / or engineering techniques to control a computer to achieve the disclosed subject matter. The term "article of art" as used herein is intended to cover a computer program accessible from any computer-readable device, machine-readable device, computer-readable carrier, computer-readable medium, machine-readable medium, or computer-readable (or machine-readable) storage / communication medium. For example, computer-readable media may include, but is not limited to, magnetic storage devices such as hard disks; floppy disks; magnetic stripes; optical discs (e.g., optical discs (CDs), digital video discs (DVDs), Blu-ray disc™ (BD)); smart cards; flash memory devices (e.g., cards, sticks, key drives); and / or analog storage devices and / or virtual devices of any of the aforementioned computer-readable media. Of course, those skilled in the art will recognize that many modifications can be made to this configuration without departing from the scope or spirit of the various embodiments.

[0088] The above description of the embodiments illustrated in this disclosure, including the content set forth in the abstract, is not intended to be exhaustive or to limit the disclosed embodiments to their precise forms. While specific embodiments and examples have been described herein for illustrative purposes, those skilled in the art will recognize that various modifications can be made within the scope of these embodiments and examples.

[0089] In this regard, while the subject matter has been described herein in conjunction with various embodiments and corresponding figures, it will be understood, where applicable, that other similar embodiments may be used, or modifications and additions may be made to the described embodiments to perform the same, similar, alternative, or substitute functions of the disclosed subject matter without departing from it. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but should be interpreted broadly and broadly in accordance with the following appended claims.

Claims

1. An event activity detection device, the device comprising: Microelectromechanical systems (MEMS) microphones, including: MEMS transducers; and A circuit for activity detection, wherein the circuit includes: The first node is configured to send or receive data associated with a clock signal; and The second node is configured to operate in a first mode during the power-up phase of the device and in a second mode after the power-up phase of the device is completed, wherein the second node is configured to receive a signal that causes the device to perform the activity detection based on activity determination, wherein the second node is a MEMS transducer selector pin, the second node reads the configuration of internal registers during the power-up phase of the device and serves as a single-wire communication interface after the power-up phase of the device is completed.

2. The apparatus of claim 1, wherein, The circuit also includes a third node configured to transmit one or more acoustic signals.

3. The apparatus of claim 1, wherein, When operating in the second mode, the second node is configured as a communication interface for the activity detection.

4. The apparatus of claim 3, wherein, The communication interface is configured to send signals or receive signals associated with the activity detection.

5. The apparatus of claim 3, wherein, The communication interface is used for write access and read access to the internal registers associated with the MEMS transducer.

6. The apparatus of claim 3, wherein, The communication interface is a serial interface.

7. The apparatus of claim 1, wherein, The MEMS transducer includes a MEMS acoustic sensor that receives acoustic signals including acoustic signal frequencies.

8. The device according to claim 1, wherein the MEMS microphone further includes a serial interface for communicating with external devices.

9. The apparatus of claim 1, wherein, The activity detection is based on acoustic activity, which includes one of the following: speech, keywords, collisions, explosions, gunshots, broken glass, and unsafe sound levels.

10. The apparatus of claim 1, wherein, The signal is a first received signal, and the device further includes an optical sensor, and when operating in the second mode, the second node is configured to send a transmit signal when a second signal from the optical sensor exceeds a threshold.

11. The apparatus of claim 1, wherein, The signal is a first received signal, and the device further includes a humidity sensor, and when operating in the second mode, the second node is configured to send a transmit signal when a second signal from the humidity sensor exceeds a threshold.

12. The device according to claim 1, wherein the voltage at the second node indicates the position of the device in the device system.

13. A method for event activity detection, the method comprising: It was determined that the microelectromechanical system (MEMS) device was no longer in the initialization state; After determining that the MEMS device is no longer in the initialization state, the selector node is used as a single-wire communication interface through the MEMS microphone of the MEMS device. The selector node reads the configuration of the internal register in the initialization state. The selector node is the MEMS transducer selector pin. The first signal instructing the MEMS device to perform acoustic activity detection is received via the MEMS microphone of the MEMS device. The MEMS microphone receives one or more acoustic signals. Using the MEMS microphone, determine that one or more acoustic signals satisfy defined acoustic characteristics; and A second signal is output through the MEMS microphone, the second signal including information indicating that the acoustic activity detected at the MEMS device is greater than the defined acoustic characteristics.

14. The method of claim 13, wherein, The defined acoustic characteristics include spectral signal levels.

15. The method of claim 13, wherein, Receiving the first signal includes receiving the first signal at the selector node of the MEMS microphone.

16. The method of claim 13, wherein, Outputting the second signal includes outputting the second signal at the selector node of the MEMS microphone.

17. The method of claim 13, further comprising: Upon receiving the first signal, stop the external clock or reduce the frequency.

18. The method of claim 13, further comprising: The defined acoustic properties are received during the initialization state.

19. The method of claim 13, wherein, The acoustic signal is a first acoustic signal, and the method further includes: After a delay and before receiving the clock signal, a second acoustic signal is determined to satisfy the defined acoustic characteristics among one or more acoustic signals.

20. The method of claim 19, further comprising: After the second determination, the defined acoustic properties are changed.

21. The method of claim 13, further comprising: Receive clock start signal or clock at normal operating frequency; as well as Interrupt the acoustic activity detection.

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