Automobile diagnosis circuit suitable for MQTT cloud technology

Abstract

The utility model discloses an automobile diagnosis circuit suitable for MQTT cloud technology, which comprises a master control IC chip and an MQTT module circuit, the MQTT module circuit is connected with the master control IC through a UART serial port on an ESP32-3C chip to establish a data transmission channel, and a low-level enable reset circuit is realized through an SOT-143 reset chip. Peripheral elements are reduced, stability and reliability of the circuit are improved, and more efficient communication and diagnostic data transmission can be realized.

Description

Technical Field

[0001] The utility model relates to the field of automobile fault diagnosis, and in particular to an automobile diagnostic circuit suitable for MQTT cloud technology. Background Art

[0002] Existing vehicle fault diagnosis primarily relies on a vehicle diagnostic instrument connected to the vehicle's OBD (On-Board Diagnostics) interface to read and analyze vehicle fault information. This is typically accomplished via Bluetooth using a VCI (Vehicle Communication Interface) module. Bluetooth-connected VCI boxes offer certain advantages. They reduce the complexity of wiring harnesses, allowing maintenance personnel to perform diagnostics around the vehicle or even remotely. Compared to traditional wired VCIs, Bluetooth VCI boxes are more convenient to use. Maintenance personnel can wirelessly connect to the VCI box from a professional diagnostic console, such as a tablet, within a range of 10 to 50 meters to perform vehicle fault diagnosis.

[0003] However, existing wireless VCI boxes still have certain limitations. Bluetooth communication range is relatively limited, typically only covering a few dozen meters. This may not meet the needs of all diagnostic scenarios in some large repair sites. Due to the low hardware utilization of the circuit design in existing VCI boxes, VCI boxes can only transmit and receive data via Bluetooth, which greatly reduces diagnostic efficiency. Currently, some have developed vehicle diagnostics using MQTT technology, which can achieve longer-range vehicle diagnostics. However, the existing VCI box circuit is not suitable for MQTT-based vehicle diagnostics, and no circuit improvements have been made for MQTT-based vehicle diagnostics.

[0004] Therefore, there is an urgent need for an automobile diagnostic circuit suitable for MQTT cloud technology that can meet the automobile diagnosis needs based on MQTT technology. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides an automobile diagnostic circuit suitable for MQTT cloud technology. The circuit sets a switching pin to switch between Bluetooth and WIFI, and sends a Bluetooth switching signal to the MQTT module circuit through the main control IC chip. The data communication mode can be switched according to the application needs, thereby improving the utilization efficiency of the hardware circuit and being suitable for automobile diagnostic scenarios based on MQTT technology.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The invention relates to an automobile diagnostic circuit applicable to MQTT cloud technology, comprising a main control IC chip and an MQTT module circuit, wherein the MQTT module circuit comprises an ESP32-3C chip and a SOT-143 reset chip, wherein the serial port transmitting pin UART_TXD of the ESP32-3C chip is connected to the serial port receiving pin of the IC chip, thereby forming a data transmitting channel, and the serial port receiving pin UART_RXD of the ESP32-3C chip is connected to the serial port transmitting pin of the IC chip, thereby forming a data receiving channel, and the GPIO3 pin of the ESP32-3C chip is connected to the serial port receiving pin of the IC chip, thereby forming a data receiving channel. The ESP32-3C chip's CHIP_EN pin is connected to the RST pin of the SOT-143 reset chip, and the ESP32-3C chip's VDD pin is connected to the VCC terminal, which is then connected to capacitor C96 and then to ground. The ESP32-3C chip's GND1 and GND2 pins are both grounded. The SOT-143 reset chip's VCC pin is connected to capacitor C97 and then to ground, and the power supply is also connected. The SOT-143 reset chip's GND pin is also grounded.

[0008] By establishing data transmission channels and data receiving channels, data can be transmitted bidirectionally between the IC chip and the ESP32-3C chip.

[0009] According to a further technical solution, the circuit also includes a VCI box, which processes the vehicle data obtained from the OBD interface circuit through an AD conversion circuit and transmits the vehicle data to a main control IC chip. The main control IC chip filters the data and then transmits the data to the MQTT circuit.

[0010] A further technical solution is that the OBD interface circuit includes pins 1-25 of the OBD interface, pins 4-5 and pins 27-28 of the OBD interface are grounded respectively, and pin 26 of the OBD interface is connected to the inductor L11 and then grounded; pins 1-3 and pins 6-15 are respectively connected to the cathode of the diode, and the anode of the diode is grounded; pin 16 is connected to the anode of the bidirectional diode, and the other end of the anode of the bidirectional diode is connected to the ground, and pin 16 is connected to the power supply; pins 17-25 are connected to the cathode of the diode, and the anode of the diode is grounded.

[0011] According to a further technical solution, the resistance of the inductor L11 is 60 ohms and can pass a current of 3 amperes.

[0012] According to a further technical solution, the diode is a voltage-stabilizing diode, and the bidirectional diode is a bidirectional voltage-stabilizing diode.

[0013] According to a further technical solution, the power supply connected to the VCC terminal is 3.3V, and the capacitor C97 is 0.1 microfarad.

[0014] According to a further technical solution, the model of the SOT-143 reset chip is VP811SEUS / NC.

[0015] As a further technical solution, the four VIO_01 pins of the IC chip are connected in parallel with capacitor C68 through capacitors C66, C67, C69, and C70, and then grounded, and connected to the MCU power supply at the same time.

[0016] According to a further technical solution, the capacitors C66, C67, C69 and C70 are all 0.1 microfarads, and the maximum DC voltage they can withstand in the circuit is 50V. The capacitor C68 is 1 microfarad, and the MCU power supply is 3.3V. Beneficial effects

[0017] Compared with the prior art, the present invention has significant advantages:

[0018] 1. The circuit of this utility model is suitable for automobile diagnosis based on MQTT cloud technology. This circuit breaks through the distance limitation of traditional Bluetooth communication, enabling maintenance personnel to remotely diagnose vehicles in an environment covered by the network, greatly improving the convenience and flexibility of diagnosis.

[0019] 2. The utility model can switch between Bluetooth and WiFi communication through the switching pin on the ESP32-3C chip, allowing maintenance personnel to independently select the communication method according to different application scenarios, thereby improving the operating efficiency of the VCI box.

[0020] 3. This utility model is directly connected to the main control IC through the UART serial port on the ESP32-3C chip, and uses the SOT-143 reset chip to achieve low-level enabled circuit reset, which simplifies the hardware circuit structure, reduces peripheral components, and improves the stability and reliability of the circuit, contributing to more efficient communication and diagnostic data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the circuit diagram of the utility model (the main control IC chip is omitted);

[0022] Figure 2 This is the circuit diagram of the main control IC chip;

[0023] Figure 3 This is the circuit diagram of the OBDII interface circuit. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Example

[0025] like Figure 1-3As shown, an automobile diagnostic circuit suitable for MQTT cloud technology includes a main control IC chip and an MQTT module circuit. The MQTT module circuit includes an ESP32-3C chip and a SOT-143 reset chip. The serial port sending pin UART_TXD of the ESP32-3C chip is connected to the serial port receiving pin PB3_UART2_RXD of the IC chip to form a data sending channel. The serial port receiving pin UART_RXD of the ESP32-3C chip is connected to the serial port sending pin PB2_UART2_TXD of the IC chip to form a data receiving channel. The GPIO3 pin PB3_E of the ESP32-3C chip is connected to the serial port receiving pin PB2_UART2_TXD of the IC chip to form a data receiving channel. SP32_BT_State is connected to pin PA27 of the IC chip, receives the Bluetooth switching signal transmitted by the main control chip, and sets the network transmission status and Bluetooth transmission status through the main control IC chip; the CHIP_EN pin of the ESP32-3C chip is connected to the RST pin of the SOT-143 reset chip, and the VDD pin of the ESP32-3C chip is connected to the VCC end, and the VCC end is connected to capacitor C96 and then grounded; the GND1 and GND2 pins of the ESP32-3C chip are both grounded; the VCC pin of the SOT-143 reset chip is connected to capacitor C97 and then grounded, and is also connected to the power supply, and the GND pin of the SOT-143 reset chip is grounded.

[0026] The establishment of data transmission and reception channels ensures bidirectional data transmission between the IC chip and the ESP32-3C chip. The CHIP_EN pin, also known as the reset pin, is connected to a SOT-143 reset chip, allowing the SOT-143 reset chip to transmit a low level to the ESP32-3C chip, resetting the circuit.

[0027] The circuit also includes a VCI box, which processes the vehicle data obtained from the OBD interface circuit through an AD conversion circuit and transmits the vehicle data to a main control IC chip. The main control IC chip filters the data and then transmits the data to the MQTT circuit.

[0028] The OBD interface circuit includes OBD interface pins 1-25, OBD interface pins 4-5 (OBD_04, OBD_05) and pins 27-28 (OBD_27, OBD_28) are grounded respectively, and OBD interface pin 26 is connected to inductor L11 and then grounded; pins 1-3 (OBD_01-OBD_03) and pins 6-15 (OBD_06-OBD_15) are respectively connected to the cathode of the diode, and the anode of the diode is grounded. These pins are pins for reading data. By connecting to the voltage regulator diode, the voltage is stabilized to protect data transmission to the VCI; pin 16 (OBD_16) is connected to the anode of the bidirectional diode, the other end of the anode of the bidirectional diode is connected to the ground, and pin 16 is connected to the power supply; pins 17-25 (OBD_17-OBD_25) are connected to the cathode of the diode, and the anode of the diode is grounded.

[0029] The resistance of the inductor L11 is 60 ohms and can pass a current of 3 amperes.

[0030] The diode is a voltage-stabilizing diode, and the bidirectional diode is a bidirectional voltage-stabilizing diode.

[0031] The power supply connected to the VCC terminal is 3.3V, and the capacitor C97 is 0.1 microfarad.

[0032] The model of the SOT-143 reset chip is VP811SEUS / NC.

[0033] The four VIO_01 pins of the IC chip are connected in parallel to capacitors C66, C67, C69, and C70, connected to capacitor C68, and then to ground. The filter capacitors also connect to the MCU power supply. The filter capacitors can filter out noise and ensure stable circuit operation.

[0034] The capacitors C66, C67, C69 and C70 are all 0.1 microfarads, and the maximum DC voltage they can withstand in the circuit is 50V. The capacitor C68 is 1 microfarad, and the MCU power supply is 3.3V.

[0035] This utility model adds an MQTT module circuit to the existing VCI box circuit. This circuit utilizes the serial port transceiver pins of the main control IC chip to establish data transmission with the MQTT module circuit. The MQTT module circuit is equipped with a Bluetooth and Wi-Fi switching pin. The main control IC chip sends a Bluetooth switching signal to the MQTT module, which can switch the data communication mode according to the application scenario, thereby improving the efficiency of hardware circuit utilization. MQTT-based vehicle diagnostics involve an operational MQTT protocol. The VCI box connects to the server through this protocol. The server forwards and processes the diagnostic data from the VCI box. The user terminal device then obtains this data through the server, parses it, and displays it. This breaks through the distance limitation of traditional Bluetooth communication. As long as there is network coverage, maintenance personnel can remotely diagnose the vehicle, solving the technical problem of the short distance of existing Bluetooth communication.

Claims

1. An automotive diagnostic circuit suitable for MQTT cloud technology, including a main control IC chip, characterized by: It also includes an MQTT module circuit, which includes an ESP32-3C chip and a SOT-143 reset chip. The serial port sending pin UART_TXD of the ESP32-3C chip is connected to the serial port receiving pin of the IC chip to form a data sending channel, and the serial port receiving pin UART_RXD of the ESP32-3C chip is connected to the serial port sending pin of the IC chip to form a data receiving channel. The GPIO3 pin of the ESP32-3C chip is connected to the PA27 pin of the IC chip to receive the Bluetooth switching signal transmitted by the IC chip; the CHIP_EN pin of the ESP32-3C chip is connected to the RST pin of the SOT-143 reset chip, the VDD pin of the ESP32-3C chip is connected to the VCC end, and the VCC end is connected to capacitor C96 and then grounded; the GND1 and GND2 pins of the ESP32-3C chip are both grounded; the VCC pin of the SOT-143 reset chip is connected to capacitor C97 and then grounded, and is also connected to a power supply, and the GND pin of the SOT-143 reset chip is grounded.

2. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 1, characterized in that: It also includes a VCI box, which processes the vehicle data obtained from the OBD interface circuit through an AD conversion circuit and transmits the vehicle data to a main control IC chip. The main control IC chip filters the data and then transmits the data to the MQTT module circuit.

3. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 2, characterized in that: The OBD interface circuit includes pins 1-25 of the OBD interface, pins 4-5 and pins 27-28 of the OBD interface are grounded respectively, and pin 26 of the OBD interface is connected to the inductor L11 and then grounded; pins 1-3 and pins 6-15 are respectively connected to the cathode of the diode, and the anode of the diode is grounded; pin 16 is connected to the anode of the bidirectional diode, and the other end of the anode of the bidirectional diode is connected to the ground, and pin 16 is connected to the power supply; pins 17-25 are connected to the cathode of the diode, and the anode of the diode is grounded.

4. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 3, characterized in that: The resistance of the inductor L11 is 60 ohms and can pass a current of 3 amperes.

5. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 3, characterized in that: The diode is a voltage-stabilizing diode, and the bidirectional diode is a bidirectional voltage-stabilizing diode.

6. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 1, characterized in that: The power supply connected to the VCC terminal is 3.3V, and the capacitor C97 is 0.1 microfarad.

7. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 1, characterized in that: The model of the SOT-143 reset chip is VP811SEUS / NC.

8. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 1, characterized in that: The four VIO_01 pins of the IC chip are connected in parallel with capacitor C68 through capacitors C66, C67, C69, and C70, and then grounded and connected to the MCU power supply.

9. The automobile diagnostic circuit applicable to MQTT cloud technology according to claim 8, characterized in that: The capacitors C66, C67, C69 and C70 are all 0.1 microfarads, and the maximum DC voltage they can withstand in the circuit is 50V. The capacitor C68 is 1 microfarad, and the MCU power supply is 3.3V.

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