Vehicle diagnosis flashing device

Abstract

The utility model relates to a vehicle diagnosis flashing device. The device comprises a signal isolation unit which is connected with a K line of a vehicle and is used for electrically isolating K line signals of the vehicle; the K line / TTL signal conversion unit is connected with the signal isolation unit, and the K line / TTL signal conversion unit is used for receiving the K line signal of the vehicle and converting the K line signal of the vehicle into a TTL level; and the TTL / USB interface conversion unit is used for converting a TTL interface into a USB interface and is connected with a USB host through the USB interface. The circuit can adapt to different vehicle voltages, can isolate interference and impact caused by the instant change of the vehicle voltage, guarantees communication under poor conditions, and protects a USB interface of a computer.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile diagnosis, in particular to a vehicle diagnosis flash writing device. Background Art

[0002] In the current vehicle testing or diagnosis process, when flashing the software, it is usually necessary to complete the module flashing function through serial port transfer signals. This flashing method that relies on the serial port has certain limitations. First, it cannot adapt to different vehicle voltages. Since the voltages of different vehicles vary greatly, the traditional serial port transfer signal method cannot be effectively adjusted to adapt to these changes; second, when the vehicle voltage changes instantly, such as starting or shutting down the engine or the current shock of other electronic devices, the traditional serial port connection method lacks effective electrical isolation measures, and the USB interface of the host computer is easily disturbed and impacted, which may affect the stability and safety of the flashing process, and then affect the performance and reliability after the flashing. Summary of the invention

[0003] To this end, the utility model provides a vehicle diagnostic flashing device that can adapt to different vehicle voltages and can isolate interference and impact caused by instantaneous changes in vehicle voltage, thereby ensuring communication under adverse conditions and protecting the USB interface of the computer.

[0004] In order to solve the above technical problems, the utility model provides a vehicle diagnostic flash writing device, comprising:

[0005] A signal isolation unit is connected to the K line of the vehicle, and is used to electrically isolate the K line signal of the vehicle;

[0006] A K-line / TTL signal conversion unit, connected to the signal isolation unit, the K-line / TTL signal conversion unit is used to receive the K-line signal of the vehicle and convert the K-line signal of the vehicle into a TTL level;

[0007] The TTL / USB interface conversion unit is used to convert the TTL interface into a USB interface and connect to a USB host via the USB interface.

[0008] In one implementation of the present invention, the signal isolation unit includes a PC817 optocoupler.

[0009] In one implementation of the present utility model, the K-line / TTL signal conversion unit includes a chip MC33199.

[0010] In one implementation of the utility model, the TTL / USB interface conversion unit includes a chip PL2303HX.

[0011] In one implementation manner of the utility model, the USB host is connected to the USB interface via a USB bus.

[0012] In one implementation of the present utility model, the USB bus selects a Type A connector.

[0013] The above technical solution of the utility model has the following advantages compared with the prior art:

[0014] The utility model discloses a vehicle diagnostic flashing device, which integrates a signal isolation unit and adopts a USB communication protocol. It has the ability to adapt to different vehicle voltages and can effectively isolate electrical interference and impact caused by automobile voltage fluctuations or transients, thereby ensuring stable communication under various voltage conditions and preventing potential damage to the USB interface of the computer.

[0015] In addition, the flash writing device of the utility model does not rely on an external clock circuit, simplifies the device structure, has low production cost, and is easy to manufacture on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments of the utility model in combination with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the overall structure of the vehicle diagnostic flash writing device of the utility model.

[0018] Figure 2 It is a circuit structure diagram of the PC817 optocoupler of the utility model.

[0019] Figure 3 It is a schematic diagram of the circuit structure of the utility model chip MC33199.

[0020] Figure 4 This is a schematic diagram of the circuit structure of the practical chip PL2303HXD. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0022] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0023] In the present utility model, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present utility model, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0024] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0025] Reference Figure 1 As shown, a vehicle diagnostic flash writing device of the utility model comprises:

[0026] A signal isolation unit is connected to the K line of the vehicle, and is used to electrically isolate the K line signal of the vehicle;

[0027] A K-line / TTL signal conversion unit, connected to the signal isolation unit, the K-line / TTL signal conversion unit is used to receive the K-line signal of the vehicle and convert the K-line signal of the vehicle into a TTL level;

[0028] The TTL / USB interface conversion unit is used to convert the TTL interface into a USB interface and connect to a USB host via the USB interface.

[0029] K-line is a diagnostic protocol that is a standard following ISO 14230. It is similar to the serial standard interface technology RS232 and is based on a typical UART circuit. In asynchronous transmission, the start and stop bits are used to synchronize the sending and receiving of data. This means that the system does not require an additional clock line and can be applied to unidirectional lines.

[0030] In one embodiment, the signal isolation unit includes a PC817 optical coupler. Its circuit structure is shown in FIG. Figure 2 As shown; the USB host includes a computer.

[0031] The PC817 optocoupler consists of an infrared emitting diode (IR LED) and a phototransistor optically coupled to it. The infrared emitting diode and the phototransistor are optically coupled together. The electrical signal is optically transmitted between the input side and the output side without any physical connection between the two sides. The optocoupler PC817 is often used as a coupling device in various functional circuits that require relatively precise functions. It has the function of completely isolating the upper and lower circuits without affecting each other. By integrating the signal isolation unit, this device can effectively isolate the electrical interference and impact caused by automobile voltage fluctuations or transients. The use of the PC817 optocoupler can prevent high-voltage interference signals from directly affecting the diagnostic equipment, enhancing the safety and reliability of the flashing process.

[0032] In one embodiment, the K-line / TTL signal conversion unit includes a chip MC33199. The communication interface conversion chip MC33199 is a bidirectional, half-duplex communication interface chip developed by Freescale specifically for vehicle diagnosis. Its circuit structure refers to Figure 3 shown.

[0033] In one embodiment, the TTL / USB interface conversion unit includes a chip PL2303HX. Its circuit structure is as follows Figure 4 As shown. The chip PL2303HX is a highly integrated interface converter under the PL2303 series, which can provide a solution for conveniently connecting an RS232 full-duplex asynchronous serial communication device with a USB functional interface, and the chip does not require an external crystal oscillator. It can effectively convert the vehicle's TTL signal into a USB signal, while protecting the USB interface of the computer (USB host) from changes in the vehicle's electrical system, reducing the risk of hardware damage.

[0034] In one embodiment, the USB host is connected to the USB interface via a USB bus, and the USB bus selects a Type A connector.

[0035] Compared with the RS232 bus, the USB has a faster transmission rate, so many computers have replaced the RS232 serial interface with the USB interface. The device does not rely on an external clock line, reducing the number and complexity of components, which not only simplifies the overall design of the device, but also helps to reduce production costs, making it more suitable for large-scale manufacturing.

[0036] When in use, first connect the signal isolation unit to the vehicle's K line through the adapter interface. The K line is the vehicle's diagnostic line, usually located at the diagnostic port (OBD-II port) near the cockpit; connect the TTL / USB interface conversion unit to the USB port of the diagnostic computer or host computer through the USB interface; start the relevant vehicle diagnostic software, and the software sends an initialization command to the vehicle diagnostic flashing device through the USB interface to prepare to start the diagnosis or flashing operation; when the signal on the vehicle's K line is activated, the signal isolation unit first receives these signals and performs electrical isolation processing through the PC817 optical coupler to protect the device from electrical interference; the isolated signal is transmitted to the K line / TTL signal conversion unit, and the MC33199 chip converts it into a TTL level signal; the TTL signal is received by the TTL / USB interface conversion unit, and converted into a USB format signal through the PL2303HXD chip, and transmitted to the connected computer system; the computer analyzes the data received through the USB interface, and performs corresponding diagnostic checks or flashes new software to the vehicle's electronic control unit (ECU) as needed.

[0037] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to examples, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A vehicle diagnostic flashing device, characterized in that: include: A signal isolation unit is connected to the K line of the vehicle, and is used to electrically isolate the K line signal of the vehicle; A K-line / TTL signal conversion unit, connected to the signal isolation unit, the K-line / TTL signal conversion unit is used to receive the K-line signal of the vehicle and convert the K-line signal of the vehicle into a TTL level; The TTL / USB interface conversion unit is used to convert the TTL interface into a USB interface and connect to a USB host via the USB interface.

2. A vehicle diagnostic flashing device according to claim 1, characterized in that: The signal isolation unit includes a PC817 optical coupler.

3. A vehicle diagnostic flashing device according to claim 1, characterized in that: The K-line / TTL signal conversion unit includes a chip MC33199.

4. A vehicle diagnostic flashing device according to claim 1, characterized in that: The TTL / USB interface conversion unit includes a chip PL2303HX.

5. A vehicle diagnostic flashing device according to claim 1, characterized in that: The USB host is connected to the USB interface via a USB bus.

6. A vehicle diagnostic flashing device according to claim 5, characterized in that: The USB bus selects a Type A connector.

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