Interface circuit integrating serial port and USB interface functions and OTG maintenance line

Abstract

The utility model relates to the technical field of electronic equipment interfaces, in particular to an interface circuit integrating functions of a serial port and a USB (universal serial bus) interface and an OTG (on-the-go) maintenance line, the interface circuit integrates the serial port and the USB interface to a TypeC USB female head, so that the physical space is obviously optimized, the miniaturization design of electronic equipment is powerfully promoted, and meanwhile, the service life of the electronic equipment is prolonged. According to the interface circuit, the electronic equipment can simultaneously meet the maintenance requirements of a serial port and a USB (Universal Serial Bus), and the compatibility and the practicability of the equipment are remarkably improved; according to the interface circuit integrating the functions of the serial port and the USB interface, the TypeA USB female head and the TypeC USB male head are combined to form the matched OTG maintenance line, so that the OTG maintenance line can be widely compatible with various USB devices, the connection process is greatly simplified, the operation convenience is improved, the interface circuit integrating the functions of the serial port and the USB interface is combined with the OTG maintenance line, and the interface circuit is more convenient to use. And the number of cables and interfaces required to be operated by maintenance personnel in the maintenance process is effectively reduced, so that the efficiency of maintenance operation is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic device interface, in particular to an interface circuit integrating serial port and USB interface functions and an OTG maintenance line. BACKGROUND

[0002] With the rapid development of electronic technology, the types and functions of electronic devices are increasing, and the demand for maintenance and debugging of these devices is also growing. In the process of maintenance and debugging of electronic devices, serial port and USB interface are two commonly used interface technologies. Serial port is a traditional interface used for low-speed communication between devices, while USB (Universal Serial Bus) interface is a more modern interface that supports high-speed data transmission and power supply. These two interfaces play an important role in the maintenance and debugging of electronic devices.

[0003] In current technical solutions, serial port and USB interface are usually applied as two independent entities for maintenance and debugging of electronic devices. For example, a serial port debugging system and method provided by patent application CN115878404A and a USB debugging circuit provided by patent application CN218273380U. However, since both serial port and USB interface need to occupy independent physical space, this limits the miniaturization development of electronic devices to some extent, and since serial port and USB interface often need to be used simultaneously in actual operation, maintenance personnel have to carry and operate multiple cables and interfaces, which not only increases the complexity of operation, but also reduces work efficiency. CONTENT OF THE UTILITY MODEL

[0004] Therefore, it is necessary to provide an interface circuit integrating serial port and USB interface functions and an OTG maintenance line to solve the problems of large physical space occupation and complex maintenance and debugging operation of current serial port and USB interface as independent interfaces.

[0005] In a first aspect, the application provides an interface circuit integrating serial port and USB interface functions, the interface circuit comprising a TypeC USB female head, the TypeC USB female head comprising an A1 pin, an A2 pin, an A3 pin, an A4 pin, an A5 pin, an A6 pin, an A7 pin, an A8 pin, an A9 pin, an A10 pin, an A11 pin, an A12 pin, a B1 pin, a B2 pin, a B3 pin, a B4 pin, a B5 pin, a B6 pin, a B7 pin, a B8 pin, a B9 pin, a B10 pin, a B11 pin and a B12 pin, the A4 pin and the B9 pin are VBUS_USB interfaces, the A4 pin is connected to the A9 pin, the B9 pin is connected to the B4 pin, the A5 pin and the B5 pin are USB_ID interfaces, the A6 pin and the B6 pin are USB_DP interfaces, the A7 pin and the B7 pin are USB_DM interfaces, the A10 pin and the B10 pin are TX serial interfaces, the A11 pin and the B11 pin are RX serial interfaces, the A1 pin, the A12 pin, the B1 pin and the B12 pin are grounded.

[0006] Further, the B10 pin and the B11 pin of the TypeC USB female head are provided with resistors.

[0007] Further, the A4 pin of the TypeC USB female head is connected to a capacitor which is then grounded.

[0008] Further, the capacitance of the capacitor is 1 μF.

[0009] Further, the interface circuit further comprises an external device connector, the external device connector comprising a 1 pin, a 2 pin and a 3 pin, the 1 pin being grounded, the 2 pin being the USB_ID interface, and the 3 pin being connected to a power signal.

[0010] Further, the power signal is a 1.8V power signal.

[0011] In a second aspect, the application provides an OTG maintenance line, a first end of the OTG maintenance line being a TypeC USB male head connected to the TypeC USB female head in the interface circuit of the first aspect, a second end of the OTG maintenance line comprising a TypeA USB female head connected to other USB devices and a TXD signal line, an RXD signal line and a GND line drawn from the TypeC USB male head; one end of the TXD signal line, the RXD signal line and the GND line being wrapped with a heat shrink sleeve, and the other end being connected to a Dupont female head.

[0012] Further, the total length of the OTG maintenance line is 150 mm ± 10 mm.

[0013] Further, the length of the TXD signal line, the RXD signal line and the GND line is 100 mm.

[0014] Further, the pitch of the pin of the Dupont female connector is 2.54 mm, and the cross-sectional side length is 0.6 mm.

[0015] In the interface circuit and the OTG maintenance line, the interface circuit realizes significant optimization of physical space by integrating the serial port and the USB interface into the TypeC USB female head, which effectively promotes the miniaturization design of the electronic device, and at the same time, the interface circuit enables the electronic device to simultaneously meet the maintenance requirements of the serial port and the USB, thereby significantly improving the compatibility and practicality of the device; the matching OTG maintenance line adopts the combination of the TypeA USB female head and the TypeC USB male head, which not only enables the OTG maintenance line to be widely compatible with various USB devices, but also greatly simplifies the connection process and improves the convenience of operation; the combination of the interface circuit and the OTG maintenance line effectively reduces the number of cables and interfaces required for the maintenance personnel to operate during the maintenance process, thereby significantly improving the efficiency of the maintenance operation. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The schematic diagram of the interface circuit integrating the serial port and the USB interface function in one embodiment;

[0017] Figure 2 The PCB diagram of the TypeC USB female head in one embodiment;

[0018] Figure 3 The structural schematic diagram of the OTG maintenance line in one embodiment;

[0019] Figure 4 The PCB diagram of the TypeC USB male head in one embodiment. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0021] The application provides an interface circuit integrating serial port and USB interface functions, mainly used for realizing U disk upgrade, USB debugging, serial port debugging and other functions. The interface circuit realizes a multifunctional maintenance interface by integrating multiple interfaces and components. At the same time, through the TypeC USB female head and J4 connector in the circuit, users can conveniently connect external devices for maintenance operation. Some specific embodiments are provided below to describe the interface circuit integrating serial port and USB interface functions of the application in detail.

[0022] Embodiment 1

[0023] Figure 1 An interface circuit integrating serial port and USB interface functions is shown, including a TypeC USB female head and an external device connector J4. The TypeC USB female head is a multifunctional interface supporting USB data transmission and power supply, and providing reversible plug-in function. The external device connector J4 is used to connect external devices such as U disk or other USB devices.

[0024] The TypeC USB female head includes A1 pin, A2 pin, A3 pin, A4 pin, A5 pin, A6 pin, A7 pin, A8 pin, A9 pin, A10 pin, A11 pin, A12 pin, B1 pin, B2 pin, B3 pin, B4 pin, B5 pin, B6 pin, B7 pin, B8 pin, B9 pin, B10 pin, B11 pin and B12 pin, the A4 pin and the B9 pin are VBUS_USB interfaces, the A4 pin is connected with the A9 pin, the B9 pin is connected with the B4 pin, the A5 pin and the B5 pin are USB_ID interfaces, the A6 pin and the B6 pin are USB_DP interfaces, the A7 pin and the B7 pin are USB_DM interfaces, the A10 pin and the B10 pin are TX serial interfaces, and the A11 pin and the B11 pin are RX serial interfaces. The A1 pin, the A12 pin, the B1 pin and the B12 pin are grounded, and the B1 pin is connected with the ground wire in the USB data line. Specifically, the 1 pin, the 2 pin, the 3 pin and the 4 pin of the TypeC USB female head are ground pins, the A1 pin is connected with the 1 pin, the A12 pin is connected with the 4 pin, the B1 pin is connected with the 3 pin, and the B12 pin is connected with the 2 pin. The B10 pin is provided with a resistor R177, the B11 pin is provided with a resistor R178, the A4 pin is connected with a capacitor C55 and then grounded, and the capacitance of the capacitor C55 is 1 μF.

[0025] Among them, the USB_ID interface is used to identify the type of device connected to the USB port, especially in the USB OTG (On-The-Go) configuration, this interface helps to determine whether the device is a host or a slave. USB_ID can be connected to the input pin of the microcontroller, so that the software can flexibly configure the role of the device according to the identified device type.

[0026] The VBUS_USB interface connects to the power line in the USB data cable, providing a stable 5V power supply to the connected device. The USB_DP (data positive) interface connects to the USB_D+ data line in the USB differential data cable, and the USB_DM (data negative) interface connects to the USB_D- data line in the USB differential data cable. These three interfaces—VBUS_USB, USB_DP, and USB_DM—work together to ensure that the device can successfully receive the required power and achieve high-speed, stable data communication.

[0027] The RX (receive) and TX (transmit) serial interfaces are used for serial communication, allowing devices to exchange data with other devices via serial ports. In circuits, the RX and TX serial interfaces are typically connected to the serial communication port of a microcontroller for debugging or data transmission.

[0028] Capacitor C55 is typically placed at the power input terminal to filter power and smooth voltage fluctuations on the power line, protecting sensitive electronic components from voltage spikes and reducing power supply noise.

[0029] Resistors R177 and R178 are used for signal conditioning. They can be used as pull-up or pull-down resistors to ensure that the signal line is in a known state when there is no drive, so as to maintain signal integrity and prevent uncertain states caused by the signal line being floating.

[0030] Figure 2 The diagram shows the PCB layout of the Type-C USB female connector, detailing its pin configuration. Each pin performs a specific function, covering critical tasks such as power supply, data transmission, and grounding. Furthermore, from... Figure 2 It can be observed that the pin functions within the interface are symmetrical, which means that the device can work normally regardless of the insertion direction when the male connector is inserted into the female connector. This design greatly improves the user's convenience and the device's compatibility.

[0031] The external device connector J4 includes a single-pole double-throw (SPDT) switch. The stationary terminal of the SPDT switch is pin 2, and the moving terminals are pins 1 and 3. Pin 3 is connected to a 1.8V power supply signal, pin 2 is the USB_ID interface, and pin 1 is grounded. When an external device is connected to connector J4, the user can change the voltage level of the USB_ID interface by switching the moving terminal of the switch to pin 1 or pin 3, thereby triggering different recognitions or responses from the microcontroller to the USB device. For example, when pin 2 is connected to pin 3, the USB_ID interface is at a high level, and the microcontroller can recognize and confirm the connected external device. Conversely, when pin 2 is connected to pin 1, the USB_ID interface is at a low level, and the microcontroller will not recognize the connected external device, treating it as disconnected. Therefore, the external device connector J4 allows users to easily connect and disconnect external devices for data transfer or device upgrades.

[0032] This embodiment integrates serial and USB interface functions into a single maintenance interface, significantly improving the compatibility and ease of use of electronic devices. This integrated design reduces the number of independent interfaces required by the device, simplifying maintenance and debugging processes. Users can perform operations such as USB flash drive upgrades, USB debugging, and serial port debugging without switching between multiple interfaces. Furthermore, the application of the Type-C interface not only provides high-speed data transmission and power supply but also enhances the user experience due to its reversible pluggable feature. This interface circuit solves the compatibility and ease-of-use problems inherent in traditional serial and USB interfaces during maintenance, making the miniaturization of electronic devices possible.

[0033] Example 2

[0034] Based on Embodiment 1, this embodiment also provides a specially designed OTG maintenance cable, which uses a combination of a Type A USB female connector and a Type C USB male connector to achieve connection with external USB devices and supports functions such as USB flash drive upgrade, USB debugging, and serial port debugging.

[0035] Figure 3 The structure of an OTG maintenance cable is shown. The first end of the OTG maintenance cable is a Type-C USB male connector that connects to the Type-C USB female connector in the above embodiment. The second end includes a Type-A USB female connector that connects to other USB devices and TXD signal lines, RXD signal lines, and GND lines that are led out from the Type-C USB male connector. One end of the TXD signal line, RXD signal line, and GND line is covered by a heat-shrink tubing 100, and the other end is connected to a DuPont female connector 200.

[0036] The total length of the OTG maintenance cable is 150mm ± 10mm, excluding the connectors at both ends. The TXD, RXD, and GND signal lines are marked in red, green, and black, respectively. The TXD and RXD signal lines are used for serial data transmission. Each of the TXD, RXD, and GND signal lines is 100mm long, and the front ends of all three lines are wrapped in heat-shrink tubing to protect the cable and ensure connection stability. The rear ends use DuPont female connectors, which can easily connect to pins with a 2.54mm pitch and a 0.6mm side cross-section. This is a widely used standard specification, facilitating quick connection to various electronic components and making maintenance and debugging more convenient and efficient.

[0037] Figure 4 The diagram shows the PCB layout of the Type-C USB male connector, detailing its pin configuration. A 5.1kΩ resistor needs to be connected between pins B1 (GND) and B5 (USB_ID) of the Type-C USB male connector to enable the recognition of storage devices such as USB flash drives in OTG (On-The-Go) mode. Specifically, the USB_ID signal is high by default with no pull-up or pull-down resistors. In this mode, the Type-A USB female connector is in slave mode and can be used as a virtual serial or Ethernet port to connect to devices such as computers. When connecting a USB flash drive to the Type-A USB female connector, first connect the Type-C USB male connector of the OTG protection cable to the Type-C USB female connector on the interface circuit. After connection, the resistor pulls the USB_ID signal low, putting the Type-A USB female connector in master mode and enabling it to recognize the USB flash drive.

[0038] This embodiment of the OTG maintenance cable provides a flexible and universal connection method through the combination of a Type A USB female connector and a Type C USB male connector, making the maintenance cable compatible with a variety of USB devices. This design not only simplifies the connection method, but also improves the versatility and applicability of the maintenance cable by using a DuPont female connector and 2.54mm pitch pin connections, simplifying maintenance operations, enhancing device compatibility and ease of use, and providing users with an efficient, convenient, and reliable maintenance interface solution.

[0039] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0040] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An interface circuit integrating serial port and USB interface functions, characterized in that, The interface circuit includes a Type-C USB female connector, the Type-C... The USB female connector includes pins A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11, and B12. Pins A4 and B9 are both VBUS_USB interfaces, with pin A4 connected to pin A9 and pin B9 connected to pin B4. Pins A5 and B5 are both USB_ID interfaces, pins A6 and B6 are both USB_DP interfaces, pins A7 and B7 are both USB_DM interfaces, pins A10 and B10 are both TX serial interfaces, and pins A11 and B11 are both RX serial interfaces. Pins A1, A12, B1, and B12 are all grounded.

2. The interface circuit integrating serial port and USB interface functions according to claim 1, characterized in that, The Type-C USB female connector has resistors on pins B10 and B11.

3. The interface circuit integrating serial port and USB interface functions according to claim 1, characterized in that, The A4 pin of the Type-C USB female connector is connected to a capacitor and then grounded.

4. The interface circuit integrating serial port and USB interface functions according to claim 3, characterized in that, The capacitance of the capacitor is 1μF.

5. The interface circuit integrating serial port and USB interface functions according to claim 1, characterized in that, The interface circuit also includes an external device connector, which has pins 1, 2, and 3. Pin 1 is grounded, pin 2 is the USB_ID interface, and pin 3 is connected to a power signal.

6. The interface circuit integrating serial port and USB interface functions according to claim 5, characterized in that, The power signal is a 1.8V power signal.

7. An OTG maintenance cable, characterized in that, The first end of the OTG maintenance line is a Type-C USB male connector that connects to the Type-C USB female connector in the interface circuit as described in any one of claims 1-6. The second end includes a Type-A USB female connector that connects to other USB devices and TXD signal lines, RXD signal lines, and GND lines that are led out from the Type-C USB male connector. One end of the TXD signal line, RXD signal line, and GND line is covered by a heat-shrink tubing, and the other end is connected to a DuPont female connector.

8. The OTG maintenance cable according to claim 7, characterized in that, The total length of the OTG maintenance cable is 150mm ± 10mm.

9. The OTG maintenance cable according to claim 7, characterized in that, The lengths of the TXD signal line, the RXD signal line, and the GND line are all 100mm.

10. The OTG maintenance cable according to claim 7, characterized in that, The pin spacing of the DuPont female connector is 2.54 mm, and the side length of the cross section is 0.6 mm.

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