Research And Application Of Vihicle Data Communication Based On OBD

With the improvement of people’s living standard, more and more people have automotives. Getting data information related to cars, is not only the demand of car manufacturers and auto repair personnel, but also the needs of the masses of consumer groups. Current, the vigorous development of mobile phone technology makes phones’ function and practicablity more and more strongger. And the phone is more and more closely connected with people’s life. Getting the relevant data via Bluetooth is reliable and convenient. Implementation of mobile phones and cars data communication is also a new direction of research and development.This paper designs a data communication system of the vehicle, to get real-time data of car through On-Board Diagnostics(OBD) and implement the data communication with mobile phone by Bluetooth technology. This paper studies the vehicle bus protocol, including K line protocol based on ISO-9141 and ISO-14230, SAE-J1850 protocol, CAN bus protocol based on SAE-J1939 and ISO-15765, the way of data communication of On-Board Diagnostics, OBD and the Bluetooth communication protocol. For auto data acquisition this paper achieves in two ways: CAN bus data acquisition based on the ISO-15765-4 protocol and car K line data acquisition based on ISO-14230 protocol. The car-related data acquired can be stored in the EEPROM chip 24C02 and can be read again later. For car data communication based on ISO-15765-4 protocol of CAN bus, this paper designs CAN nodes by MCP2515 and TJA1050 as the main controller device to establish a communication connection through OBD, achieving two separate modules. One module realizes the data receiving and sending on CAN bus of vehicle OBD, receives response messages of request command.Another module circuit captures data transmission on CAN bus. Data transmitting content is controlled by mobile phone, sent to MCU via Bluetooth. For vehicle K line data acquisition based on ISO-14230, this paper establishes communication with vehicle K line by the conversion chip MC33290. This article also realizes the K line data sending and receiving controlled by PC based on Lab VIEW.The paper tests each circuit module function, meets the design requirements. Data acquisition module captures the vehicle CAN bus data efficiently, achieves data communication by Bluetooth mobile phone or PC and data storage.Data capture module successfully received data on the CAN bus transmission and display. Vehicle K line is effecitive realization of data acquisition and PC interface control. Finally, the paper analyzes and summarizes the test results and puts forward the prospect.