USB HID-Bluetooth conversion circuit and Bluetooth adapter

Abstract

The utility model discloses a USB HID-Bluetooth conversion circuit and a Bluetooth adapter, which are used for connecting peripherals and realizing wireless connection between the peripherals and terminal equipment in a wireless mode. Comprising a main control sub-circuit in wireless connection with terminal equipment, a USB connection sub-circuit electrically connected with the main control sub-circuit and a power supply sub-circuit for supplying power to the main control sub-circuit and the USB connection sub-circuit, and a peripheral signal output end of the USB connection sub-circuit is electrically connected with a peripheral signal input end of the main control sub-circuit. And the main control sub-circuit is in communication connection with terminal equipment, so that wireless connection between the peripheral equipment and the terminal equipment is realized. Compared with the prior art, the conversion circuit provided by the utility model is high in integration level, and facilitates the miniaturization of the Bluetooth adapter so as to be convenient to carry.

Description

Technical Field

[0001] The utility model relates to the technical field of Bluetooth conversion, in particular to a USB HID-Bluetooth conversion circuit and a Bluetooth adapter. Background Art

[0002] In the current technological era, the design of laptops is becoming increasingly diversified to meet the personalized needs of different users. However, with the rapid development of technology and the change of office methods, many users find that the number of USB ports on their laptops often cannot meet the needs of daily office work. In the daily office environment, in addition to connecting conventional devices such as external storage devices and printers, it is also necessary to connect input devices such as mice, keyboards, digital tablets, and controllers, which makes the number of USB ports an issue that cannot be ignored.

[0003] In order to solve this problem, a variety of solutions have emerged on the market. One common method is to use a Bluetooth mouse, keyboard, tablet or controller. However, although this method solves the problem of insufficient interfaces, it is usually costly, and for some users, the price of Bluetooth devices may be expensive, which is not the most economical choice. Another solution is to use an expansion dock. The expansion dock can expand multiple USB ports, allowing users to connect more devices. However, the expansion dock is usually large in size and not very convenient to carry. After connecting the expansion dock, it will also occupy a USB port, which to a certain extent does not completely solve the problem of insufficient interfaces. Utility Model Content

[0004] In view of this, the purpose of the utility model is to provide a USB HID-Bluetooth conversion circuit and a Bluetooth adapter, so as to provide a circuit architecture to solve the problems in the prior art of high cost of connecting laptop computers to Bluetooth peripherals and inconvenience of carrying expansion docks.

[0005] To achieve the above-mentioned purpose, a technical solution of the utility model provides a USB HID-Bluetooth conversion circuit, which is used to connect peripherals and realize wireless connection between the peripherals and terminal devices in a wireless manner, including a main control subcircuit wirelessly connected to the terminal device, a USB connection subcircuit electrically connected to the main control subcircuit, and a power supply subcircuit for powering the main control subcircuit and the USB connection subcircuit, the peripheral signal output end of the USB connection subcircuit is electrically connected to the peripheral signal input end of the main control subcircuit, the main control subcircuit is communicatively connected to the terminal device, and the wireless connection between the peripheral and the terminal device is realized.

[0006] Furthermore, the main control subcircuit includes a main control chip U2, a resistor R1, a resistor R5, a resistor R13, a capacitor C4 and a capacitor C5, and the main control chip U2 is communicatively connected to the terminal device; a wireless transmission module is integrated in the main control chip U2, and the main control chip U2 is communicatively connected to the terminal device through the wireless transmission module;

[0007] The VCC pin and EN pin of the main control chip U2 are electrically connected to the second power supply end of the power sub-circuit, the VCC pin of the main control chip U2 is also grounded via capacitors C4 and C5 respectively, and the GND pin of the main control chip U2 is grounded; the IO2 pin of the main control chip U2 is electrically connected to the first power supply end of the power sub-circuit via the resistor R1, and the IO2 pin of the main control chip U2 is also grounded via the resistor R13; the IO8 pin of the main control chip U2 is electrically connected to the second power supply end of the power sub-circuit via the resistor R5.

[0008] Furthermore, the USB connection subcircuit is limited to an external interface USB3 of an external device, the VCC1 pin and the VCC2 pin of the external interface USB3 are both electrically connected to the third power supply terminal of the power subcircuit, the GND1 pin and the GND2 pin of the external interface USB3 are both grounded, and the D-1 pin, D+1 pin, D-2 pin and D+2 pin of the external interface USB3 are respectively electrically connected to the IO4 pin, IO5 pin, IO6 pin and IO7 pin of the main control chip U2.

[0009] Furthermore, the power subcircuit includes a battery connection unit, a power management unit electrically connected to the battery connection unit, a charging interface unit connected to the power management unit, and a voltage stabilizing unit electrically connected to the power management unit, the battery connection unit is externally connected to a battery, the first power supply terminal is formed on the battery connection unit to output a first power supply voltage, the second power supply terminal is formed on the voltage stabilizing unit to output a second power supply voltage, the third power supply terminal is formed on the power management unit to output a third power supply voltage, the third power supply terminal of the power management unit is also electrically connected to the voltage stabilizing unit, so that the voltage stabilizing unit converts the third power supply voltage into a second power supply voltage, and the charging output terminal of the charging interface unit is electrically connected to the first charging input terminal and the second charging input terminal of the power management unit.

[0010] Furthermore, the battery connection unit has a battery interface J1, pins 1, 3 and 4 of the battery interface J1 are all grounded, and pin 2 of the battery interface J1 forms the first power supply terminal and outputs a first power supply voltage.

[0011] Further, the power management unit includes a power management chip U3, an indicator light LED1, a diode D2, a diode D3, a resistor R3, a resistor R6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12 and an inductor L2;

[0012] The VCC pin of the power management chip U3 is electrically connected to the CHRG pin of the power management chip U3 via the resistor R6 and the indicator LED1 in sequence, and the VCC pin of the power management chip U3 is also grounded via the capacitor C7. The VCC pin of the power management chip U3 also forms the first charging input terminal and is electrically connected to the charging output terminal of the charging interface unit. The BAT pin of the power management chip U3 is electrically connected to the first power supply terminal, and the BAT pin of the power management chip U3 is also grounded via the capacitors C8, C9 and C10, respectively. The LX pin of the power management chip U3 is connected to the first power supply terminal via the inductor L2. The LX pin of the power management chip U3 is also electrically connected to the VOUT of the power management chip U3 via the diode D2. The VOUT pin of the power management chip U3 is also electrically connected to the charging output terminal of the charging interface unit via the diode D3 to form a second charging input terminal. The VOUT pin of the power management chip U3 is also grounded via capacitors C11 and C12 respectively. The VOUT pin of the power management chip U3 forms the third power supply terminal and outputs the third power supply voltage. The PROG pin of the power management chip U3 is grounded via the resistor R3. The GND pin of the power management chip U3 is grounded.

[0013] Furthermore, the charging interface unit includes an interface chip U5 and a capacitor C3;

[0014] The VBUS1 pin and the VBUS2 pin of the interface chip U5 are connected to form a charging output terminal electrically connected to the power management unit. The VBUS1 pin of the interface chip U5 is also grounded via a capacitor C3. The GND pin and the SHELL pin of the interface chip are both grounded.

[0015] Furthermore, the voltage stabilizing unit includes a voltage stabilizing chip U1, a capacitor C1, a capacitor C2 and a capacitor C6;

[0016] The Vin pin of the voltage stabilizing chip U1 is electrically connected to the third power supply end and the Vin pin of the voltage stabilizing chip U1 is also grounded via the capacitor C6. The Vout1 pin and the Vout2 pin of the voltage stabilizing chip U1 form the second power supply end and output the second power supply voltage. The Vout pin of the voltage stabilizing chip U1 is also grounded via the capacitor C1 and the capacitor C2 respectively, and the GND pin of the voltage stabilizing chip U1 is grounded.

[0017] Furthermore, it also includes a program download subcircuit electrically connected to the main control subcircuit, and the program download subcircuit includes a program download chip U4 and a capacitor C13;

[0018] The V3 pin and VCC pin of the program download chip U4 are electrically connected to the second power supply end, the VCC pin of the program download chip U4 is also grounded via capacitor C13, the RXD pin and TXD pin of the program download chip U4 are electrically connected to the U0RXD pin and U0TXD pin of the main control chip U2 respectively, the UD+ pin of the program download chip U4 is electrically connected to the DP1 pin and DP2 pin of the interface chip U5, the UD- pin of the program download chip U4 is electrically connected to the DN1 pin and DN2 pin of the interface chip U5, and the GND pin of the program download chip U4 is grounded.

[0019] To achieve the above-mentioned purpose, another technical solution of the utility model provides a Bluetooth adapter including a shell and the USB HID-Bluetooth conversion circuit as described above, the main control subcircuit and the power supply subcircuit are both built into the shell, and an opening is formed on the shell to expose the USB connection subcircuit to connect external devices.

[0020] The utility model is provided with a main control chip with a wireless transmission module, which converts the signal of the external input device into a Bluetooth signal or a WiFi signal and then transmits it wirelessly to the terminal device, and converts the signal of the terminal device into a Bluetooth signal or a WiFi signal and then transmits it wirelessly to the external output device, so that the peripheral device and the terminal device communicate without a physical connection, which can not only improve the portability of the device and reduce the use of cables, but also is not limited to the number of USB ports of the terminal device and the specific location of the terminal device when connecting, thereby improving the flexibility of the connection between the peripheral device and the terminal device. In addition, the utility model also provides a battery connection unit and a charging interface unit, so that the Bluetooth adapter can be powered by both an external power supply and a battery, and the battery can be charged by using an external power supply by providing a power management unit, further increasing the flexibility of the use of the peripheral device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural block diagram of a USB HID-Bluetooth conversion circuit according to an embodiment of the present invention.

[0022] Figure 2 This is the circuit schematic diagram of the main control sub-circuit.

[0023] Figure 3 This is the circuit schematic diagram of the USB connection sub-circuit.

[0024] Figure 4 This is the circuit schematic diagram of the battery connection unit.

[0025] Figure 5 This is the circuit schematic of the power management unit.

[0026] Figure 6 This is the circuit schematic diagram of the charging interface unit.

[0027] Figure 7 This is the circuit schematic diagram of the voltage stabilizing unit.

[0028] Figure 8 Download the subcircuit schematic for the program.

[0029] The accompanying drawings in the specification are numeraled as follows:

[0030] Main control sub-circuit 1, USB connection sub-circuit 2, power supply sub-circuit 3, battery connection unit 31, power management unit 32, charging interface unit 33, voltage stabilization unit 34, program download sub-circuit 4. DETAILED DESCRIPTION

[0031] The following is further described in detail through specific implementation methods:

[0032] Example

[0033] The USB HID-Bluetooth conversion circuit of the present utility model can be connected to peripherals (such as external input devices such as mice, keyboards, microphones, and external output devices such as headphones and speakers) in a wired manner, and can realize wireless connection between peripherals and terminal devices (such as laptops, other terminal devices with Bluetooth or WiFi functions, etc.) in a wireless manner (Bluetooth or WiFi, this embodiment mainly uses Bluetooth), including converting the signal of the external input device into a Bluetooth signal or a WiFi signal and then wirelessly transmitting it to the terminal device, and also including converting the signal of the terminal device into a Bluetooth signal or a WiFi signal and then wirelessly transmitting it to the external output device.

[0034] Please refer to Figure 1 The USB HID-Bluetooth conversion circuit of the utility model includes a main control subcircuit 1, a USB connection subcircuit 2 and a power supply subcircuit 3. The main control subcircuit 1 is wirelessly connected to the terminal device, the USB connection subcircuit 2 is electrically connected to the main control subcircuit 1, the main control subcircuit 1 and the terminal device are connected in communication (preferably in Bluetooth mode in this embodiment), the USB connection subcircuit 2 has a peripheral access port, the peripheral access port is connected to the USB connection subcircuit 2 in a wired manner, and the peripheral signal output end of the USB connection subcircuit 2 is electrically connected to the peripheral signal input end of the main control subcircuit 1 to achieve wireless connection between the peripheral and the terminal device.

[0035] The power subcircuit 3 is electrically connected to both the main control subcircuit 1 and the USB connection subcircuit 2. Specifically, the power subcircuit 3 has a first power supply terminal, a second power supply terminal and a third power supply terminal. The first power supply terminal and the second power supply terminal are electrically connected to the main control subcircuit 1, and the third power supply terminal is electrically connected to the USB connection subcircuit 2, so as to supply power to the main control subcircuit 1 and the USB connection subcircuit 2 respectively, thereby ensuring the normal operation of the entire conversion circuit. In this embodiment, the power subcircuit 3 is preferably powered by a lithium battery, and the first power supply terminal outputs a first power supply voltage, and the first power supply voltage is preferably a battery voltage of the lithium battery, i.e., VBAT; the second power supply terminal outputs a second power supply voltage, and the third power supply terminal outputs a third power supply voltage. The second power supply voltage and the third power supply voltage are both converted and stabilized by the power subcircuit 3 and then output to the main control subcircuit 1 and the USB connection subcircuit 2. The second power supply voltage is preferably 3.3V, and the third power supply voltage is preferably 5V.

[0036] Please refer to Figure 2 , the main control subcircuit 1 includes a main control chip U2, a resistor R1, a resistor R5, a resistor R13, a capacitor C4 and a capacitor C5, the main control chip U2 is connected to the terminal device for communication, and the main control subcircuit 1 can convert the signal of the external input device into a Bluetooth signal and then transmit it wirelessly to the terminal device, and convert the signal of the terminal device into a Bluetooth signal and then transmit it wirelessly to the external output device. In this embodiment, the main control chip U2 is preferably implemented by a signal ESP-C3-32S-4M chip, and the main control chip U2 is integrated with a wireless transmission module of an ESP32-C3 chip, which supports 2.4GHz WiFi and Bluetooth BLE5.0 connections, so that the main control chip U2 can communicate with the terminal device through the wireless transmission module.

[0037] Specifically, the VCC pin and EN pin of the main control chip U2 are electrically connected to the second power supply end of the power supply sub-circuit 3 to access the second power supply voltage. The VCC pin of the main control chip U2 is also grounded via capacitors C4 and C5 respectively, and the GND pin of the main control chip U2 is grounded. Capacitors C4 and C5 are filter capacitors to filter the power supply voltage input by the main control chip U2 to prevent voltage fluctuations, thereby ensuring the normal operation of the main control chip U2. The IO2 pin of the main control chip U2 is electrically connected to the first power supply end of the power supply sub-circuit 3 via resistor R1, and the IO2 pin of the main control chip U2 is also grounded via resistor R13. The IO8 pin of the main control chip U2 is electrically connected to the second power supply end of the power supply sub-circuit 3 via resistor R5. Resistors R1, R5 and R13 are current limiting resistors to prevent the main control chip U3 from being damaged due to overcurrent, thereby improving the reliability of the main control sub-circuit 1. The IO4 pin, IO5 pin, IO6 pin and IO7 pin of the main control chip U2 form an electrical connection between the peripheral signal input end of the main control sub-circuit 1 and the peripheral signal output end of the USB connection sub-circuit 2 to achieve communication between the USB connection sub-circuit 2 and the main control chip U2.

[0038] Please refer to Figure 3 The USB connection subcircuit 2 is defined as an external interface USB3 of the peripheral device. The USB connection subcircuit 2 can be physically connected to the peripheral device to achieve signal transmission between the peripheral device and the peripheral device. In this embodiment, the external interface USB3 is provided with an external device access port to connect with the peripheral device. The external interface USB3 can be implemented by a conventional USB interface, such as a USB 3.0 interface.

[0039] Specifically, the VCC1 pin and the VCC2 pin of the external interface USB3 are both electrically connected to the third power supply terminal of the power sub-circuit 3 to access the third power supply voltage to ensure the normal operation of the external interface USB3; the GND1 pin and the GND2 pin of the external interface USB3 are both grounded to provide shielding and prevent interference to ensure the stability and reliability of the external interface USB3 during data transmission. The D-1 pin, D+1 pin, D-2 pin and D+2 pin of the external interface USB3 form the peripheral signal output terminal of the USB connection sub-circuit 2, and the D-1 pin, D+1 pin, D-2 pin and D+2 pin of the external interface USB3 are electrically connected to the IO4 pin, IO5 pin, IO6 pin and IO7 pin of the main control chip U2 respectively to realize the signal transmission between the external interface USB3 and the main control chip U2.

[0040] Please refer to Figure 1 The power subcircuit 3 includes a battery connection unit 31, a power management unit 32, a charging interface unit 33 and a voltage stabilizing unit 34. The battery connection unit 31 is connected to an external battery (lithium battery) to form the main power supply source of the entire conversion circuit. The first power supply terminal is formed on the battery connection unit 31 to output the first power supply voltage. The power management unit 32 is electrically connected to the battery connection unit 31, and the power management unit 32 is specifically connected to the first power supply terminal of the battery connection unit 31. The third power supply terminal is formed on the power management unit 32. The power management unit 32 can convert the first power supply voltage output by the battery into a third power supply voltage and output it. The charging interface unit 33 is electrically connected to the power management unit 32, that is, the charging output terminal of the charging interface unit 33 is electrically connected to the first charging input terminal and the second charging input terminal of the power management unit 32, so that the charging interface unit 33 can directly power the main control subcircuit 1 and the USB connection subcircuit 2 through the power management unit 32, and can also charge the battery through the power management unit 32, so that the conversion circuit can be used independently under the power supply of the battery and can also be used in the case of connecting an external power line, which increases the diversity of application and improves the use experience. The voltage stabilizing unit 34 is electrically connected to the power management unit 32, and the voltage stabilizing unit 34 is specifically connected to the third power supply terminal of the power management unit 32. The second power supply terminal is formed on the voltage stabilizing unit 34. The voltage stabilizing unit 34 can convert the connected third power supply voltage into a second power supply voltage and output it.

[0041] Please refer to Figure 4 The battery connection unit 31 has a battery interface J1. The battery connection unit 31 can be connected to an external lithium battery, and the model of the battery connection unit 31 is preferably XH2.54-2PSMD.

[0042] Specifically, pins 1, 3 and 4 of the battery interface J1 are all grounded, and pin 2 of the battery interface J1 forms a first power supply terminal and outputs a first power supply voltage, so as to be electrically connected to pin IO8 of the main control chip U2 through resistor R4 and to the power management unit 32.

[0043] Please refer to Figure 5 The power management unit 32 includes a power management chip U3, an indicator LED1, a diode D2, a diode D3, a resistor R3, a resistor R6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12 and an inductor L2. The power management unit 32 is used for charging management of the battery in the battery connection unit 31, and can provide a stable power supply for the subsequent circuit; in this embodiment, the model of the power management chip U3 is preferably TP5400, and the diode D2 and the diode D3 are Schottky diodes, wherein the model of the diode D2 is preferably SS32, and the model of the diode D3 is preferably SS14.

[0044] Specifically, the VCC pin of the power management chip U3 is electrically connected to the CHRG pin of the power management chip U3 via the resistor R6 and the indicator LED1 in turn. Specifically, the cathode of the indicator LED1 is electrically connected to the CHRG pin of the power management chip U3, and the anode of the indicator LED1 is electrically connected to the resistor R6. When charging the battery, the CHRG pin is pulled to a low level by the internal switch, indicating that charging is in progress, otherwise the CHRG pin is in a high impedance state, and the high and low levels output by the CHRG pin control the on and off of the indicator LED1 to indicate the charging status. The VCC pin of the power management chip U3 is also grounded via capacitor C7, and capacitor C7 is a filter capacitor to filter out clutter and AC components in the power supply, making the DC voltage smoother and storing electrical energy at the same time. The VCC pin of the power management chip U3 also forms a first charging input terminal that is electrically connected to the charging output terminal of the charging interface unit 33 to access an external power supply. The BAT pin of the power management chip U3 is electrically connected to the first power supply end to connect to the battery and charge the battery. The BAT pin of the power management chip U3 is also grounded via capacitors C8, C9 and C10 respectively. Capacitors C8, C9 and C10 are filter capacitors to filter out noise and AC components in the power supply to make the DC voltage smoother while storing electrical energy. The LX pin of the power management chip U3 is electrically connected to the first power supply terminal via the inductor L2, and the LX pin of the power management chip U3 is also electrically connected to the VOUT of the power management chip U3 via the diode D2. The VOUT pin of the power management chip U3 is also electrically connected to the charging output terminal of the charging interface unit 33 via the diode D3 to form a second charging input terminal. Specifically, the LX pin of the power management chip U3 is electrically connected to the anode of the diode D2, the cathode of the diode D2 is electrically connected to the cathode of the diode D3, and the anode of the diode D3 forms a second charging input terminal and is electrically connected to the charging output terminal of the charging interface unit 33. The diodes D2 and D3 can protect the circuit from the influence of reverse current, thereby preventing the reverse voltage from appearing at the second charging input terminal. The VOUT pin of the power management chip U3 is also grounded via capacitors C11 and C12 respectively. The VOUT pin of the power management chip U3 forms a third power supply terminal and outputs a third power supply voltage. The capacitors C11 and C12 can smooth the output of the third power supply voltage, reduce noise and ripple, and ensure the stability of the output of the third power supply voltage. The PROG pin of the power management chip U3 is grounded via the resistor R3 , and the GND pin of the power management chip U3 is grounded.

[0045] Please refer to Figure 6 The charging interface unit 33 includes an interface chip U5 and a capacitor C3. The charging interface unit 33 can be connected to an external power supply to power the entire conversion circuit and can also charge the battery; in this embodiment, the charging interface unit 33 is preferably implemented using a Type-C interface, and the model of the interface chip U5 is preferably TYPE_16 / 20.

[0046] Specifically, the VBUS1 pin and the VBUS2 pin of the interface chip U5 are connected to form a charging output terminal and electrically connected to the power management unit 32. Specifically, the VBUS1 pin and the VBUS2 pin of the interface chip U5 are connected to the VCC pin of the power management chip U3 and the anode of the diode D3. The VBUS1 pin of the interface chip U5 is also grounded via a capacitor C3, which is a filter capacitor to filter out clutter and AC components in the power supply to make the DC voltage smoother. The GND pin and the SHELL pin of the interface chip are both grounded.

[0047] Please refer to Figure 7 The voltage stabilizing unit 34 includes a voltage stabilizing chip U1, a capacitor C1, a capacitor C2 and a capacitor C6. The voltage stabilizing unit 34 can reduce the 5V supply voltage to a stable voltage of 3.3V; in this embodiment, the model of the voltage stabilizing chip U1 is preferably AMS1117-3.3.

[0048] Specifically, the Vin pin of the voltage regulator chip U1 is electrically connected to the third power supply terminal and the Vin pin of the voltage regulator chip U1 is also grounded via capacitor C6. Capacitor C6 is an input capacitor used to suppress ripple and noise at the input terminal, making the input third power supply voltage smoother. The Vout1 pin and Vout2 pin of the voltage regulator chip U1 form a second power supply terminal and output a second power supply voltage; the Vout pin of the voltage regulator chip U1 is also grounded via capacitor C1 and capacitor C2 respectively. Capacitor C1 and capacitor C2 are output capacitors used to filter the output second power supply voltage and suppress self-oscillation. The GND pin of the voltage regulator chip U1 is grounded.

[0049] Please refer to Figure 1 As a preferred mode of this embodiment, the USB HID-Bluetooth conversion circuit of this embodiment also includes a program download subcircuit 4 electrically connected to the main control subcircuit 1, and the program download subcircuit 4 is used to load the control program into the main control subcircuit 1. The program download subcircuit 4 is connected to the second power supply end to be powered by the power supply subcircuit 3. In addition, the main control subcircuit 1 is also connected to a wiring port H2 connected to the program download subcircuit 4, and the 1 pin of the wiring port H2 is grounded, and the 2 pin is electrically connected to the IO9 pin of the main control chip U2. When the program download subcircuit 4 is loading the control program, it is necessary to manually short-circuit the wiring port H2 to pull down the level of the IO9 pin of the main control chip U2 (i.e., grounded), so that the main control chip U2 is forced to enter the Bootloader mode, so that the program download subcircuit 4 can be programmed or the firmware can be updated. It should be known that although the program download subcircuit 4 in this embodiment can be programmed, program downloaded, etc., the key point of protection is not the program, but the circuit architecture of the entire circuit, and does not involve computer programs.

[0050] Please refer to Figure 8The program download sub-circuit 4 includes a program download chip U4 and a capacitor C13; in this embodiment, the model of the program download chip U4 is preferably CH340N.

[0051] Specifically, the V3 pin and VCC pin of the program download chip U4 are electrically connected to the second power supply end, and the VCC pin of the program download chip U4 is also grounded via capacitor C13, which is a filter capacitor. The RXD pin and TXD pin of the program download chip U4 are electrically connected to the U0RXD pin and U0TXD pin of the main control chip U2, respectively, to connect to the main control chip U2 and download the program. The UD+ pin of the program download chip U4 is electrically connected to the DP1 pin and DP2 pin of the interface chip U5, and the UD- pin of the program download chip U4 is electrically connected to the DN1 pin and DN2 pin of the interface chip U5. The program download subcircuit 4 and the power management unit 32 share the Type-C interface of the charging interface unit 33 to connect to the programming device, and download the program to the main control chip U2 through the Type-C interface. The GND pin of the program download chip U4 is grounded.

[0052] The USB HID-Bluetooth conversion circuit of this embodiment realizes the wireless connection between the peripheral device and the terminal device by setting the main control chip, so that the peripheral device and the terminal device can communicate without physical connection, which can not only improve the portability of the device and reduce the use of cables, but also is not limited by the number of USB ports of the terminal device and the specific location of the terminal device when connecting, thereby improving the flexibility of the connection between the peripheral device and the terminal device. In addition, by setting the battery connection unit 31 and the charging interface unit 33, the Bluetooth adapter can be powered by both an external power supply and a battery, and by setting the power management unit 32, the battery can be charged by an external power supply, further increasing the flexibility of the use of the peripheral device.

[0053] The structure diagram of the Bluetooth adapter of another embodiment of the utility model. The Bluetooth adapter of this embodiment includes a housing and a USB HID-Bluetooth conversion circuit as in the above embodiment, the main control subcircuit 1 and the power subcircuit 3 are both built in the housing, an opening is formed on the housing to expose the USB connection subcircuit 2 to connect to an external device, and a battery slot and a Type-C interface are also reserved on the housing, the battery slot is used to install the battery, and the Type-C interface exposes the charging interface unit 33 to facilitate connection with an external power source or device, so as to realize power supply to the battery management unit or program downloading of the program download subcircuit 4.

[0054] The Bluetooth adapter of this embodiment integrates the main control subcircuit 1, the USB connection subcircuit 2, the power subcircuit 3 and the program download subcircuit 4 in the housing, which is beneficial to improving the integration of the entire circuit, reducing the size of the Bluetooth adapter, and making it easy to carry. The Bluetooth adapter is used to achieve wireless connection between wired devices and terminal devices, which can effectively reduce the cost of peripherals.

Claims

1. A USB HID-Bluetooth conversion circuit, used to connect a peripheral device and realize wireless connection between the peripheral device and a terminal device in a wireless manner, characterized in that: The invention comprises a main control subcircuit wirelessly connected to a terminal device, a USB connection subcircuit electrically connected to the main control subcircuit, and a power supply subcircuit for supplying power to the main control subcircuit and the USB connection subcircuit, wherein the peripheral signal output end of the USB connection subcircuit is electrically connected to the peripheral signal input end of the main control subcircuit, and the main control subcircuit is communicatively connected to the terminal device, thereby realizing wireless connection between the peripheral device and the terminal device.

2. The USB HID-Bluetooth conversion circuit according to claim 1, characterized in that: The main control subcircuit includes a main control chip U2, a resistor R1, a resistor R5, a resistor R13, a capacitor C4 and a capacitor C5, and the main control chip U2 is connected to the terminal device for communication; a wireless transmission module is integrated in the main control chip U2, and the main control chip U2 is connected to the terminal device for communication through the wireless transmission module; The VCC pin and EN pin of the main control chip U2 are electrically connected to the second power supply end of the power sub-circuit, the VCC pin of the main control chip U2 is also grounded via capacitors C4 and C5 respectively, and the GND pin of the main control chip U2 is grounded; the IO2 pin of the main control chip U2 is electrically connected to the first power supply end of the power sub-circuit via the resistor R1, and the IO2 pin of the main control chip U2 is also grounded via the resistor R13; the IO8 pin of the main control chip U2 is electrically connected to the second power supply end of the power sub-circuit via the resistor R5.

3. The USB HID-Bluetooth conversion circuit according to claim 2, characterized in that: The USB connection subcircuit is defined as an external interface USB3 for peripheral devices, the VCC1 pin and the VCC2 pin of the external interface USB3 are both electrically connected to the third power supply terminal of the power subcircuit, the GND1 pin and the GND2 pin of the external interface USB3 are both grounded, and the D-1 pin, D+1 pin, D-2 pin and D+2 pin of the external interface USB3 are respectively electrically connected to the IO4 pin, IO5 pin, IO6 pin and IO7 pin of the main control chip U2.

4. The USB HID-Bluetooth conversion circuit according to claim 3, characterized in that: The power subcircuit includes a battery connection unit, a power management unit electrically connected to the battery connection unit, a charging interface unit connected to the power management unit, and a voltage stabilizing unit electrically connected to the power management unit. The battery connection unit is externally connected to a battery. The first power supply terminal is formed on the battery connection unit to output a first power supply voltage. The second power supply terminal is formed on the voltage stabilizing unit to output a second power supply voltage. The third power supply terminal is formed on the power management unit to output a third power supply voltage. The third power supply terminal of the power management unit is also electrically connected to the voltage stabilizing unit so that the voltage stabilizing unit converts the third power supply voltage into a second power supply voltage. The charging output terminal of the charging interface unit is electrically connected to the first charging input terminal and the second charging input terminal of the power management unit.

5. The USB HID-Bluetooth conversion circuit according to claim 4, characterized in that: The battery connection unit has a battery interface J1, pins 1, 3 and 4 of the battery interface J1 are all grounded, and pin 2 of the battery interface J1 forms the first power supply terminal and outputs a first power supply voltage.

6. The USB HID-Bluetooth conversion circuit according to claim 4, characterized in that: The power management unit includes a power management chip U3, an indicator light LED1, a diode D2, a diode D3, a resistor R3, a resistor R6, a capacitor C7, a capacitor C8, a capacitor C9, a capacitor C10, a capacitor C11, a capacitor C12 and an inductor L2; The VCC pin of the power management chip U3 is electrically connected to the CHRG pin of the power management chip U3 via the resistor R6 and the indicator LED1 in sequence, and the VCC pin of the power management chip U3 is also grounded via the capacitor C7. The VCC pin of the power management chip U3 also forms the first charging input terminal and is electrically connected to the charging output terminal of the charging interface unit. The BAT pin of the power management chip U3 is electrically connected to the first power supply terminal, and the BAT pin of the power management chip U3 is also grounded via the capacitors C8, C9 and C10, respectively. The LX pin of the power management chip U3 is connected to the first power supply terminal via the inductor L2. The LX pin of the power management chip U3 is also electrically connected to the VOUT of the power management chip U3 via the diode D2. The VOUT pin of the power management chip U3 is also electrically connected to the charging output terminal of the charging interface unit via the diode D3 to form a second charging input terminal. The VOUT pin of the power management chip U3 is also grounded via capacitors C11 and C12 respectively. The VOUT pin of the power management chip U3 forms the third power supply terminal and outputs the third power supply voltage. The PROG pin of the power management chip U3 is grounded via the resistor R3. The GND pin of the power management chip U3 is grounded.

7. The USB HID-Bluetooth conversion circuit according to claim 5, characterized in that: The charging interface unit includes an interface chip U5 and a capacitor C3; The VBUS1 pin and the VBUS2 pin of the interface chip U5 are connected to form a charging output terminal electrically connected to the power management unit. The VBUS1 pin of the interface chip U5 is also grounded via a capacitor C3. The GND pin and the SHELL pin of the interface chip are both grounded.

8. The USB HID-Bluetooth conversion circuit according to claim 4, characterized in that: The voltage stabilizing unit includes a voltage stabilizing chip U1, a capacitor C1, a capacitor C2 and a capacitor C6; The Vin pin of the voltage stabilizing chip U1 is electrically connected to the third power supply end and the Vin pin of the voltage stabilizing chip U1 is also grounded via the capacitor C6. The Vout1 pin and the Vout2 pin of the voltage stabilizing chip U1 form the second power supply end and output the second power supply voltage. The Vout pin of the voltage stabilizing chip U1 is also grounded via the capacitor C1 and the capacitor C2 respectively, and the GND pin of the voltage stabilizing chip U1 is grounded.

9. The USB HID-Bluetooth conversion circuit according to claim 7, characterized in that: It also includes a program download subcircuit electrically connected to the main control subcircuit, and the program download subcircuit includes a program download chip U4 and a capacitor C13; The V3 pin and VCC pin of the program download chip U4 are electrically connected to the second power supply end, the VCC pin of the program download chip U4 is also grounded via capacitor C13, the RXD pin and TXD pin of the program download chip U4 are electrically connected to the U0RXD pin and U0TXD pin of the main control chip U2 respectively, the UD+ pin of the program download chip U4 is electrically connected to the DP1 pin and DP2 pin of the interface chip U5, the UD- pin of the program download chip U4 is electrically connected to the DN1 pin and DN2 pin of the interface chip U5, and the GND pin of the program download chip U4 is grounded.

10. A Bluetooth adapter, characterized in that: It comprises a shell and a USBHID-Bluetooth conversion circuit as claimed in any one of claims 1 to 9, wherein the main control subcircuit and the power subcircuit are both built in the shell, and an opening is formed on the shell to expose the USB connection subcircuit to connect peripherals.

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