Design Of Monitoring System For In-Vehicle Body Network Based On CAN Bus

In-vehicle network technology is one of the prime research fields in automotive electronics in the world. Among many field busses, CAN bus is the most hopeful one which has been put into widely application. Depending on its advantages, it has become the prime communication protocol within communication network in vehicle.Monitoring and test system of in-vehicle network is a helpful tool not only in the stage of development but also in the stage of repair and maintenance. The system can help to debug nodes in the stage of development. Also, it can monitor in-vehicle network and detect network errors when the network is in use.In this article, a monitoring and test system of in-vehicle network based on CAN bus is presented. After the international and domestic development trends of in-vehicle network and bus monitoring system being introduced, the architecture of the system and top design of the scheme is determined. The system is divided into two parts, target board based on Freescale MCU and GUI programs running on PC. The communication between target board and PC is via RS232. Hardware and software design of the system is stated separately.Hardware design involves power supply circuits, CAN, SPI, UART communication interface circuits and optimizing the hardware layout to improve EMC performance. Software design involves the programs of sending/receiving CAN frame, storing error code in the target board. Also, the programs of diagnosis and online control running on PC are finished.The system meets the specification and runs stably while it is tested.