Development For An Integral Test System Of Car CAN-bus Dashboard

With the rapid development of automobile electronic technology, the apparent of Automotive Network greatly reduced the number of car interior wiring, the system costs, the signal interference between the controllers, and it also fulfilled the high-speed, accurate, real-time communications. Controller Area Network is the most widely used in the Automotive Network. CAN-bus is being used widely in foreign countries. In China, the CAN-bus technology has just started.This paper assumes basis of Jilin auto parts technology development project"R&D and product of car full electronic combination dashboard based on bus communication". This paper did a lot of research on car CAN-bus dashboard according to Automotive Network technology and the CAN-bus agreement. The paper which focus on the test of CAN-bus dashboard, integrated a complete car CAN-bus dashboard detection system.This paper firstly introduces the basic knowledge of the dashboard and the test system. And then introduced the detail of the CAN-bus communication technology of the agreement and principles are introduced.Simply, this CAN-bus dashboard test system can be considered as a CAN-signal generator.The system work process is: PC send a signal to the dashboard information driver, the dashboard driver will received information into CAN signals and then the driver send CAN signals to the CAN-network.This project is divided into two parts: the hardware design and the software programming design. Software programming part is divided into two parts: the program writing of MCU and the virtual software programming. In this project, CAN-bus dashboard test system in hardware mainly includes the following several modules: CAN control module, frequency signal producing module, the switch quantity signal driver modules, program-controlled variable resistance signal output module, serial interface communication module and car battery voltage output module. In the hardware part, this project chose Freescale MC9S12DJ128 as the micro processor core of driving signal, chose the Philips TJA1050 chip as CAN transceiver, chose the letter MAX232 chip solved serial communication interface module voltage conversion problem.In the software parts, this paper mainly introduces the MCU programming and the virtual software programming. The virtual software programming part introduces the communication rules between dashboard driver source and PC, proposed to the instrument driver source of serial communication module and CAN control module to the specific procedures writing methods. PC software programming part introduces the software compilation process by using LabWindows/CVI.In order to prevent the contretemps happens, such as pointer dithering, indicator and the alarm lamp suddenly dark destroy, etc, this paper conducted a series of electromagnetic compatibility test for the CAN-bus dashboard test system.The paper also did a lot of test on the Speed table, engine speed table, engine water thermometer, oil scale, lights and alarm lamp. The results of CAN-bus speed meter, engine speed watcher, engine water thermometer, oil scale engine temperature and alarm lamp shown the effectiveness of the test system of CAN-bus dashboard.