Automatic switching device for double USB (Universal Serial Bus) interfaces

Abstract

The embodiment of the invention provides a double-USB interface automatic switching device, the device comprises a USB multiplexing / demultiplexing switch chip, and an external communication device, an MCU and a charging chip which are respectively connected with the USB multiplexing / demultiplexing switch chip, the external communication device is connected with the USB multiplexing / demultiplexing switch chip through a USB Type-C interface, and the charging chip is connected with the external communication device through a USB Type-C interface. And the USB multiplexing / demultiplexing switch chip conducts the channels of the external communication equipment and the charging chip when the channel switching control pin is at a low level so as to charge the external communication equipment, and conducts the channels of the external communication equipment and the MCU when the channel switching control pin is at a high level so as to enable the external communication equipment to communicate with the MCU. Only a single USB interface is used, physical switch cooperation is not needed, and charging and communication functions can be switched in two USB channels according to needs by using the level.

Description

Technical Field

[0001] The present application relates to the technical field of circuit switching, and in particular to an automatic switching device for dual USB interfaces. Background Art

[0002] With the continuous development of technology, there are more and more communication devices that use batteries as power sources. These devices generally use ARM architecture MCU as the central processor. In order to facilitate function debugging, system upgrades, etc., the device will reserve a debugging and upgrading interface, which is mostly a USB interface.

[0003] In order to improve the working efficiency of the equipment, the capacity of the built-in battery in the equipment is getting larger and larger. When charging a device that uses a battery, two modes are generally used. One is to use a dedicated charging device to charge it, and the other is to use the same USB interface as a smartphone. Compared with the two modes, the second method does not require additional dedicated equipment. Most devices with built-in batteries provide users with a USB Type-C interface as a charging interface. In order to improve charging efficiency, the USB Type-C interface supports various fast charging protocols that traditional USB interfaces do not have. In addition to the private fast charging protocols of various mobile phone manufacturers, the mainstream general fast charging protocols are the PD fast charging protocol and the QC fast charging protocol. Among them, the PD fast charging protocol uses the unique CC signal line in the USB Type-C interface for transmission, and the QC fast charging protocol uses the two signal lines D+ and D- contained in all forms of USB interfaces for transmission.

[0004] Generally, two USB ports are reserved, one for system debugging, upgrading, and maintenance, and the other for charging the device, or a double-pole double-throw switch is used to manually switch between the two USB ports.

[0005] Therefore, the existing technology has the following problems: First, the device needs two physical interfaces or one physical interface plus a physical switch, which increases the volume and material cost; second, the debugging and upgrading interfaces are directly open, which increases the risk of internal information leakage. If the device has an OTA air upgrade function, the debugging and upgrading interfaces on the device are not used frequently, and it is very likely that the device will not be used throughout its life cycle. In order to be on the safe side, they must be retained, which results in a waste of space and cost. Summary of the invention

[0006] The present application provides a dual USB interface automatic switching device, the purpose of which is to use only a single USB interface without the need for a physical switch, and to switch the charging and communication functions on demand in two USB channels using the level of the voltage.

[0007] In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0008] In a first aspect, an embodiment of the present application provides a dual USB interface automatic switching device, the device comprising a USB multiplexing / demultiplexing switch chip and an external communication device, an MCU and a charging chip respectively connected to the USB multiplexing / demultiplexing switch chip, the external communication device being connected to the USB multiplexing / demultiplexing switch chip via a USB Type-C interface, and the USB multiplexing / demultiplexing switch chip comprising a channel switching control pin;

[0009] USB multiplexer / demultiplexer switch chip for:

[0010] When the channel switching control pin is at a low level, the channel between the external communication device and the charging chip is turned on to charge the external communication device;

[0011] When the channel switching control pin is at a high level, the channel between the external communication device and the MCU is turned on, so that the external communication device and the MCU communicate with each other.

[0012] In a possible implementation, the USB multiplexing / demultiplexing switch chip further includes a USB input pin, a USB first channel pin, and a USB second channel pin;

[0013] The USB input pin is connected to the external communication device, the USB first channel pin is connected to the charging chip, and the USB second channel pin is connected to the MCU.

[0014] In a possible implementation, when the channel switching control pin inputs a low level, the USB input pin connects to the USB first channel pin, and when the channel switching control pin inputs a high level, the USB input pin connects to the USB second channel pin.

[0015] In a possible implementation, the channel switching control pin is respectively connected to the GPIO control pin of the MCU and the SBU pin on the USB Type-C interface, so that the MCU or the external communication device sends a high / low level to the channel switching control pin.

[0016] In a possible implementation, a ground pin of the USB multiplexing / demultiplexing switch chip is connected to a signal ground.

[0017] In a possible implementation, a power input pin of the USB multiplexing / demultiplexing switch chip is connected to the positive electrode of the battery.

[0018] In a possible implementation, the channel switching control pin is also connected to the SUB pin of the USB Type-C interface.

[0019] In a possible implementation, the external communication device is connected to the USB Type-C interface using a common USB cable or a customized USB cable.

[0020] Compared with the prior art, the embodiment of the present application proposes that the embodiment of the present application provides a dual USB interface automatic switching device, which includes a USB multiplexing / demultiplexing switch chip and an external communication device, an MCU and a charging chip respectively connected to the USB multiplexing / demultiplexing switch chip. The external communication device is connected to the USB multiplexing / demultiplexing switch chip through a USB Type-C interface. When the channel switching control pin is at a low level, the USB multiplexing / demultiplexing switch chip turns on the channel between the external communication device and the charging chip to charge the external communication device. When the channel switching control pin is at a high level, the channel between the external communication device and the MCU is turned on, so that the external communication device and the MCU communicate. Only a single USB interface is used and no physical switch is required. The charging and communication functions can be switched on demand in the two USB channels using the level. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the structure of a dual USB interface automatic switching device proposed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0026] In the prior art, communication equipment will reserve two USB interfaces, one for system debugging, upgrading, and maintenance, and the other for charging the device or manually switching between the two USB interfaces using a double-pole double-throw switch. Therefore, the following problems will arise: First, the device requires two physical interfaces or one physical interface plus a physical switch, which increases the volume and material costs; second, the debugging and upgrading interfaces are directly open, increasing the risk of internal information leakage. If the device has an OTA air upgrade function, the debugging and upgrading interfaces on the device are not used frequently, and it is likely that the device will not be used throughout its life cycle. In order to be on the safe side, they must be retained, which results in a waste of space and cost.

[0027] In order to solve the above-mentioned technical problems, an embodiment of the present application proposes a dual USB interface automatic switching device, which uses a specific USB multiplexing / demultiplexing switch chip and a matching peripheral circuit design, and combines a special USB cable to enable the device to automatically switch between two different USB channels as needed, and this switching process does not require the user to manually operate the physical switch, which is described in detail below.

[0028] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of the dual USB interface automatic switching device proposed in the embodiment of the present application is shown, the device includes a USB multiplexing / demultiplexing switch chip and an external communication device, an MCU and a charging chip respectively connected to the USB multiplexing / demultiplexing switch chip, and the external communication device is connected to the USB multiplexing / demultiplexing switch chip through a USB Type-C interface;

[0029] USB multiplexer / demultiplexer switch chip for:

[0030] When the channel switching control pin of the USB multiplexing / demultiplexing switch chip is at a low level, the channel between the external communication device and the charging chip is turned on to charge the external communication device;

[0031] When the channel switching control pin of the USB multiplexing / demultiplexing switch chip is at a high level, the channel between the external communication device and the MCU is turned on, so that the external communication device and the MCU communicate with each other.

[0032] The external communication device can be any device that can exchange data with other electronic devices through a USB interface, such as a smart phone, a tablet computer, a USB storage drive, a digital camera, a GPS device, or other portable electronic devices that support USB connection. The dual USB interface automatic switching device proposed in the embodiment of the present application can intelligently manage the connection between the external communication device and the charging chip and the MCU (micro control unit), which is divided into a charging mode and a data communication mode.

[0033] Charging mode: When the channel switching control pin of the switch chip is at a low level, it connects the path from the external communication device to the charging chip, and the device can be charged through the USB interface.

[0034] Data communication mode: When the control pin becomes high, the path turns to connect the external communication device and the MCU, allowing data exchange or communication operations between the two.

[0035] The embodiment of the present application realizes the dual functions of charging and data communication through a single USB interface, and the switching process is completed automatically without manual intervention by the user. This solution improves the convenience and efficiency of the device and reduces the dependence on external physical switches.

[0036] In a possible implementation, the USB multiplexing / demultiplexing switch chip further includes a USB input pin, a USB first channel pin, and a USB second channel pin;

[0037] The USB input pin is connected to the external communication device, the USB first channel pin is connected to the charging chip, and the USB second channel pin is connected to the MCU.

[0038] There are three pins inside the USB multiplexing / demultiplexing switch chip, namely the USB input pin, the USB first channel pin and the USB second channel pin. The USB input pin is the interface connected to the external communication device. When the user connects these devices through the USB cable, the starting point of data and power transmission is this pin.

[0039] The first USB channel pin is responsible for connecting to the charging chip. When the switch chip control mechanism decides to turn on the charging mode (that is, the control pin is low), a path from the external communication device to the charging chip is established, thereby achieving the purpose of powering the external device.

[0040] The second channel pin of USB is connected to MCU (microcontroller unit). Under data communication requirements (i.e. the control pin is high level), it can ensure that an effective data transmission path is formed between the external communication device and MCU, facilitating the exchange of instructions and information between the two.

[0041] In a possible implementation, when the channel switching control pin inputs a low level, the USB input pin connects to the USB first channel pin, and when the channel switching control pin inputs a high level, the USB input pin connects to the USB second channel pin.

[0042] When the channel switching control pin S inputs a low level, the USB input pin D (D+ and D-) connects to the first USB channel pin D1. When the channel switching control pin inputs a high level, the USB input pin D (D+ and D-) connects to the second USB channel pin D2. The level of the control pin (low level or high level) is used to determine whether the USB data line (D+D-) is connected to the first channel (D1) or the second channel (D2), thereby realizing intelligent switching between charging and data transmission without physical intervention.

[0043] In a possible implementation, the channel switching control pin is respectively connected to the GPIO control pin of the MCU and the SBU pin on the USB Type-C interface, so that the MCU or the external communication device sends a high / low level to the channel switching control pin.

[0044] The channel switching control pin "S" receives a signal from the control pin "GPIO" of the MCU (microcontroller unit) or the SBU pin on the USB Type-C interface to determine the working mode of the USB multiplexing / demultiplexing switch chip.

[0045] When the MCU's GPIO pin outputs a high level to the "S" pin, the MCU is instructing the switch chip to enter the data communication mode, thereby connecting the external communication device to the MCU and allowing data exchange between the two. On the contrary, if the output is a low level, it indicates that the switch chip should switch to the charging mode, connecting the external device to the charging chip to ensure that the device can be charged.

[0046] Similarly, the SBU pin of the USB Type-C interface also has the ability to send control signals to the "S" pin, such as using the bidirectional communication characteristics of the Type-C interface for mode control. The SBU pin of the Type-C interface can also output high or low levels as needed to achieve remote or direct control of channel switching. It is very flexible and allows devices to dynamically adjust the functions of the USB interface through software control (MCU) or hardware interface (Type-C) according to different application scenarios or user needs, without physical intervention, which improves the user experience.

[0047] The MCU's "GPIO" pin has the function of controlling the signal output, and its level state (high level or low level) directly affects the working mode of the USB multiplexing / demultiplexing switch chip. It is divided into shutdown state, power-on default settings, and special operations to change the level state.

[0048] Shutdown state and power-on default settings: When the MCU is in shutdown state, the GPIO pin outputs a low-level signal by default. Even after powering on, if no additional settings are made, the pin will usually remain in a low-level state. This means that, without any special operations, the device will enable charging mode by default, and external communication devices can be charged through the USB interface.

[0049] Special operations change the level state: Users can change the output state of the GPIO pin through specific operations (such as a specific button combination, pressing a key quickly and continuously, or making specific settings on the supporting APP). Once these special operations are performed, the signal of the GPIO pin will be set to a high level. This change activates the data communication mode, allowing external communication devices to exchange data with the MCU.

[0050] In a possible implementation, a ground pin of the USB multiplexing / demultiplexing switch chip is connected to a signal ground.

[0051] The ground pin "GND" of the USB multiplexer / demultiplexer switch chip is used to establish a common reference potential point to ensure that all parts of the chip and the peripheral circuits connected to it have a common zero potential reference. The signal ground and power ground should be consistent in the system design to reduce ground loop interference and noise, and ensure signal purity and stable system operation.

[0052] In a possible implementation, a power input pin of the USB multiplexing / demultiplexing switch chip is connected to the positive electrode of the battery.

[0053] The power input pin of the USB multiplexer / demultiplexer switch chip is directly connected to the positive battery terminal of the device, ensuring that the chip can work normally when the device is turned on or off. The chip is directly powered by the internal battery of the device, which can ensure that the USB multiplexer / demultiplexer switch chip can realize the switching function when the device is turned on or off. By directly powering the battery, the chip can still maintain its basic operation even when the main power of the device is turned off, so that the USB interface can be smoothly switched between charging and data communication modes regardless of the device status. The flexibility of the device and the user experience are improved. Even when there is no external power supply or the device is turned off, the chip can control the switching of USB interface functions, so that external communication devices can obtain the required energy supply or data services in different scenarios.

[0054] In a possible implementation, the channel switching control pin is also connected to the SUB pin of the USB Type-C interface.

[0055] In most standard Type-C connections, the SBU (Sideband Use) pin in the USB Type-C interface is not directly involved in the normal charging or data transmission process. When using a normal Type-C cable to connect a computer, charger, etc., the SBU pin is usually undefined, that is, it is in a floating state and can be regarded as a low level.

[0056] The SBU pin is used to support the transmission of audio and video signals or other specific functions. At this time, it becomes a control or signal pin through a specific protocol (such as Alt Mode) to activate and control advanced functions. Through a special Type-C cable, the voltage of the power supply pin (Vbus) can be converted to a stable 3.3V via an LDO (low-dropout linear regulator), thereby giving the SBU pin a high level state. Such a setting may be intended to trigger certain specific devices or modes, such as establishing an enhanced data connection between certain professional devices or activating specific functional modules.

[0057] In a possible implementation, the external communication device is connected to the USB Type-C interface using a common USB cable or a customized USB cable.

[0058] Each communication device is connected to the USB Type-C interface using a common USB cable or a customized USB cable. The corresponding circuit working logic is shown in Table 1:

[0059] Table 1

[0060]

[0061]

[0062] The USB Type-C interface switches functions through control signals in different usage scenarios:

[0063] Normal charging scenario: When using a standard USB Type-C cable to connect a charger or computer, regardless of whether the MCU is powered on or not, the channel switching control pin is at a low level by default, which turns on the first channel pin of the USB. In this way, the device can carry out the normal charging process, and the charging device and the charging management chip can communicate the quick charging (QC) protocol through the D+D- pins to ensure safe and efficient charging.

[0064] MCU debugging and log reception: When the device is powered on and the MCU needs to be debugged or the operation log needs to be viewed, although the computer is still connected using a normal USB Type-C cable, the GPIO can be set to a high level by performing special operations on the MCU (such as a specific key combination or software command). This change causes channel switching, turning on the second channel pin of the USB, so that the computer can communicate directly with the MCU to exchange debugging information or download logs.

[0065] MCU system upgrade: When upgrading the MCU system, the MCU needs to suspend work during the upgrade process and cannot actively maintain the high level state of GPIO to maintain the communication path with the computer. To this end, a customized Type-C cable is required to use the SBU pin to provide a stable high-level signal to the channel switching control pin. Even if the MCU is not in operation, the first channel pin remains connected to ensure that the computer can update the MCU firmware through the USB interface and complete the system upgrade operation.

[0066] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0067] First, seamless USB channel switching: By using USB multiplexing / demultiplexing switch chips and carefully designed peripheral circuits, it is possible to seamlessly switch between charging, data communication or special functions (such as system upgrades), ensuring that users will not notice any interruptions or steps requiring manual intervention during use, thereby improving the user experience.

[0068] Second, security enhancement: Using pins in the USB Type-C interface that are not commonly used by ordinary users (such as the SBU pins discussed earlier) to control the switching logic effectively hides the control logic inside the device, increases the security barrier for access to sensitive information, and ensures that only users with the corresponding knowledge or permissions can perform specific operations.

[0069] Third, multi-function integration: This design cleverly integrates the functions of multiple interfaces such as charging, data communication and possible advanced function control with only a single USB Type-C interface, simplifying the device design and reducing the number of physical ports, saving space and improving the appearance and durability of the device.

[0070] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A dual USB interface automatic switching device, characterized in that: The device includes a USB multiplexing / demultiplexing switch chip and an external communication device, an MCU and a charging chip respectively connected to the USB multiplexing / demultiplexing switch chip, the external communication device is connected to the USB multiplexing / demultiplexing switch chip through a USB Type-C interface, and the USB multiplexing / demultiplexing switch chip includes a channel switching control pin; USB multiplexer / demultiplexer switch chip for: When the channel switching control pin is at a low level, the channel between the external communication device and the charging chip is turned on to charge the external communication device; When the channel switching control pin is at a high level, the channel between the external communication device and the MCU is turned on, so that the external communication device and the MCU communicate with each other.

2. The dual USB interface automatic switching device according to claim 1, characterized in that: The USB multiplexing / demultiplexing switch chip also includes a USB input pin, a USB first channel pin, and a USB second channel pin; The USB input pin is connected to the external communication device, the USB first channel pin is connected to the charging chip, and the USB second channel pin is connected to the MCU.

3. The dual USB interface automatic switching device according to claim 2, characterized in that: When the channel switching control pin inputs a low level, the USB input pin connects to the USB first channel pin; When the channel switching control pin inputs a high level, the USB input pin is connected to the USB second channel pin.

4. The dual USB interface automatic switching device according to claim 1, characterized in that: The channel switching control pin is respectively connected to the GPIO control pin of the MCU and the SBU pin on the USB Type-C interface, so that the MCU or the external communication device sends a high / low level to the channel switching control pin.

5. The dual USB interface automatic switching device according to claim 1, characterized in that: The ground pin of the USB multiplexer / demultiplexer switch chip is connected to the signal ground.

6. The dual USB port automatic switching device according to claim 1, characterized in that: The power input pin of the USB multiplexer / demultiplexer switch chip is connected to the positive terminal of the battery.

7. The dual USB port automatic switching device according to claim 1, characterized in that: The channel switching control pin is also connected to the SUB pin of the USB Type-C interface.

8. The dual USB port automatic switching device according to claim 1, characterized in that: The external communication device is connected to the USB Type-C interface using a common USB cable or a customized USB cable.

Images