MCU-based DB9 wire harness on-off and wire sequence detection tool

Abstract

The utility model provides a DB9 wire harness on-off and wire sequence detection tool based on an MCU. The DB9 wire harness on-off and wire sequence detection tool comprises an MCU chip, a detection circuit, a sound-light alarm circuit, an LED and buzzer control circuit, an LED and buzzer drive circuit and a power supply module. The detection circuit comprises a signal output circuit and a signal input circuit, the signal output circuit is used for transmitting high and low level signals sent by the MCU chip to the DB9 wire harness input end, and the signal input circuit is used for transmitting signals output by the DB9 wire harness output end back to the MCU chip; the sound-light alarm circuit comprises an LED and a buzzer, and is used for indicating a fault line of the DB9 wire harness and carrying out fault reminding on the DB9 wire harness through sound production. The LED and buzzer control circuit is used for transmitting a control signal between the sound-light alarm circuit and the MCU chip; the LED and buzzer driving circuit is used for transmitting electric energy between the power supply module and the sound-light alarm circuit; the power supply module is used for supplying power to the MCU chip and each circuit; and the MCU chip is used for carrying out detection logic control on the DB9 wire harness.

Description

Technical Field

[0001] This utility model relates to the field of electronic testing instrument technology, and in particular to a DB9 wire harness continuity and wire sequence testing fixture based on MCU. Background Technology

[0002] The DB9 interface is a common serial communication interface, typically used for connecting devices. Due to its ease of use and low cost, it has been widely used in the field of communication since its inception.

[0003] Existing methods for testing continuity of DB9 wiring harnesses include expensive logic analyzers, cumbersome multimeter operation, inability to determine the specific condition of the line through serial communication testing, and time-consuming and labor-intensive manual inspection which is prone to omissions. When the line has a customized design or special wiring method, the efficiency of the above tests is even lower and cannot meet the needs of batch testing. Utility Model Content

[0004] To address the aforementioned issues, this invention provides a MCU-based DB9 wiring harness continuity and sequence detection fixture. Utilizing an MCU chip, LEDs, and a buzzer, it enables rapid detection of DB9 line continuity and sequence of the DB9 wiring harness used in the CTP-800 sensor power supply box (checking for incorrect connections, short circuits, or open circuits at the four sensor terminals), significantly reducing the cost and time required for line testing.

[0005] A DB9 wire harness continuity and sequence detection fixture based on MCU includes an MCU chip, a detection circuit, an audible and visual alarm circuit, an LED and buzzer control circuit, an LED and buzzer driver circuit, and a power module.

[0006] The detection circuit includes a signal output circuit and a signal input circuit. One end of the signal output circuit is connected to the PB12 to PB15 pins of the MCU chip, and the other end is connected to the DB9 harness four-wire interface, which is used to transmit the high and low level signals sent by the MCU chip to the DB9 harness input terminal. One end of the signal input circuit is connected to the MCU chip, and the other end is connected to the DB9 harness nine-wire interface, which is used to transmit the signal output from the DB9 harness output terminal back to the MCU chip.

[0007] The audible and visual alarm circuit includes an LED and a buzzer. The LED is used to indicate the faulty line of the DB9 wiring harness, and the buzzer is used to provide a fault warning to the DB9 wiring harness by emitting sound.

[0008] The LED and buzzer control circuit is used to transmit control signals between the audible and visual alarm circuit and the MCU chip.

[0009] The LED and buzzer driving circuit is used to transmit electrical energy between the power supply module and the audible and visual alarm circuit.

[0010] The power module is used to supply power to the MCU chip and various circuits;

[0011] The MCU chip, acting as a controller, is configured to: send a high-level signal from the MCU chip, pass through the DB9 wire harness under test via the signal output circuit, and enter the MCU chip via the signal input circuit for level signal detection; based on the level signal detection results of each line of the DB9 wire harness, the MCU chip sends a control signal to the audible and visual alarm circuit to control the LED and buzzer to send corresponding alarm signals.

[0012] Optionally, the MCU chip model is GD32F103C8T6.

[0013] The advantages of this utility model over the prior art are as follows:

[0014] Compared to existing testing methods, this tooling successfully reduces the cost and time of circuit testing to meet the requirements of actual production. It is also very easy to operate and can indicate specific errors during and at the end of the test, making repairs convenient. In addition, the equipment is small in size and highly portable, and can be quickly deployed and used in different environments. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A structural block diagram of a DB9 wire harness continuity and wire sequence detection fixture based on an MCU provided in this embodiment of the present disclosure;

[0017] Figure 2 This is a diagram of the MCU chip pinout and signal output circuit.

[0018] Figure 3 This is a diagram of the signal input circuit structure.

[0019] Figure 4 This is a schematic diagram of the sound and light alarm circuit.

[0020] Figure 5 For tooling workflow diagram;

[0021] Figure 6 This is a circuit diagram of a DB9 wiring harness used in a CTP-800 sensor power supply box. Detailed Implementation

[0022] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0023] The DB9 wiring harness used in the CTP-800 sensor power supply box is taken as the detection object, such as Figure 1 As shown, this disclosure provides a DB9 wire harness continuity and sequence detection fixture based on an MCU, including an MCU chip, a detection circuit, an audible and visual alarm circuit, an LED and buzzer control circuit, an LED and buzzer driver circuit, an MCU chip, and a power module.

[0024] like Figure 2 As shown, the MCU chip is a GD32F103C8T6 chip for detection logic control. Its PB12-PB15 pins are signal output terminals. The signal output terminals are connected to a 5.08mm pin pitch quick-connect terminal (CN6) and a 3.81mm pin pitch sensor interface (CN5) to meet the requirements of the four-wire terminal interface of the sensor DB9 harness.

[0025] The detection circuit includes a signal output circuit and a signal input circuit. One end of the signal output circuit is connected to pins PB12 to PB15 of the MCU chip, and the other end is connected to a four-wire DB9 harness interface to transmit the high and low level signals emitted by the MCU chip to the DB9 harness input terminal. Figure 3 The signal input circuit shown is connected to the MCU chip at one end and externally connected to the DB9 harness nine-wire terminal interface DB9-1 to DB9-9 at the other end, which is used to transmit the signal output from the DB9 harness output terminal back to the MCU chip.

[0026] like Figure 4 As shown, the sound and light alarm circuit includes LED1-LED9 and a buzzer. LED1-LED9 are connected to the PA1-PA9 pins of the MCU chip through resistors R1-R9 to indicate the faulty line of the DB9 wiring harness. The buzzer is connected to the PB0 pin of the MCU chip to provide a fault warning to the DB9 wiring harness by emitting sound.

[0027] The testing process is as follows Figure 5 As shown, after power-on, a high-level signal is sequentially emitted by the MCU chip from pins PB12-PB15, and enters the signal output circuit as shown. Figure 6 The four-wire terminal of the DB9 harness shown is connected to the nine-wire terminal on the other side of the DB9 harness via... Figure 3 The signal input circuit shown enters the MCU chip and detects whether the corresponding line is pulled high. If the corresponding line is pulled high, the line is normally connected and there is no fault. If the corresponding line is not pulled high, the line is not connected and cannot transmit signals or power.

[0028] For example, when wire 1 of the four-wire terminal of the DB9 harness is pulled high, wires 3 and 9 of the corresponding nine-wire terminal should also be connected and pulled high. If wires 3 and 9 are not detected to be pulled high, it indicates an open circuit; if other wires are pulled high, it indicates a short circuit. Both of these indicate a faulty circuit and also prove that the wiring sequence is incorrect. Similarly, when wire 2 of the four-wire terminal is pulled high, wires 5 and 8 of the nine-wire terminal are pulled high; when wire 3 of the four-wire terminal is pulled high, wires 1 and 2 of the nine-wire terminal are pulled high; when wire 4 of the four-wire terminal is pulled high, wires 4, 6, and 7 of the nine-wire terminal are pulled high. Both of these test scenarios can pinpoint the specific faulty circuit, facilitating repair. During and at the end of the test, the faulty circuit will be immediately detected. Figure 4 The high-brightness LED1-LED9 display works by the MCU chip pulling the LED low, which increases the current through the LED and thus improves its brightness. The buzzer works on the same principle: pulling the SPEAKER low puts the transistor in a conducting state, which increases the current through the buzzer and makes it sound.

[0029] At the end of the test, if there is a fault in the DB9 wiring harness, the buzzer will beep twice to indicate the end of the test, and beep three times to indicate a fault warning. Then the next test will begin. If there is no abnormality in the DB9 wiring harness, all LED1-LED9 will be lit at low brightness, and the buzzer will only beep twice to indicate the end of the test. Then the next test will begin directly. The entire process does not require button operation, saving time and operation steps.

[0030] If the interface remains idle for an extended period, the fixture will automatically enter standby mode, waiting for the DB9 test cable to be connected to the interface before starting the test.

[0031] The low cost of this fixture lies in its use of the GD32F103C8T6 chip as the controller, with only common resistors, capacitors, LEDs, and buzzers required to meet the requirements. Its ease of operation stems from the fact that the fixture is ready to run upon power-up; simply connect the circuit to the two interfaces to complete the test. Furthermore, the four-wire interface has been optimized by replacing the straight spring clamp with a curved spring clamp, ensuring good contact while making insertion and removal of the four wires easier and extending their lifespan. Finally, its high speed is achieved through the use of an MCU for automatic circuit detection, outputting the circuit status within seconds.

[0032] The foregoing description, with reference to preferred embodiments, details the exemplary implementation of the MCU-based DB9 harness continuity and wiring sequence detection fixture proposed in this utility model. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of this utility model, and various combinations can be made to the various technical features and structures proposed in this utility model without exceeding the protection scope of this utility model, which is determined by the appended claims.

Claims

1. A MCU-based DB9 wire harness continuity and sequence detection fixture, characterized in that, Includes MCU chip, detection circuit, sound and light alarm circuit, LED and buzzer control circuit, LED and buzzer driver circuit and power module; The detection circuit includes a signal output circuit and a signal input circuit. One end of the signal output circuit is connected to the PB12 to PB15 pins of the MCU chip, and the other end is connected to the DB9 harness four-wire interface, which is used to transmit the high and low level signals sent by the MCU chip to the DB9 harness input terminal. One end of the signal input circuit is connected to the MCU chip, and the other end is connected to the DB9 harness nine-wire interface, which is used to transmit the signal output from the DB9 harness output terminal back to the MCU chip. The audible and visual alarm circuit includes an LED and a buzzer. The LED is used to indicate the faulty line of the DB9 wiring harness, and the buzzer is used to remind the DB9 wiring harness of the fault by emitting sound. The LED and buzzer control circuit is used to transmit control signals between the audible and visual alarm circuit and the MCU chip. The LED and buzzer driving circuit is used to transmit electrical energy between the power supply module and the audible and visual alarm circuit. The power module is used to supply power to the MCU chip and various circuits; The MCU chip, acting as a controller, is configured to: send a high-level signal from the MCU chip, pass through the DB9 wire harness under test via the signal output circuit, and enter the MCU chip via the signal input circuit for level signal detection; based on the level signal detection results of each line of the DB9 wire harness, the MCU chip sends a control signal to the audible and visual alarm circuit to control the LED and buzzer to send corresponding alarm signals.

2. The MCU-based DB9 wire harness continuity and sequence detection fixture according to claim 1, characterized in that, The MCU chip model is GD32F103C8T6.

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