The design and implementation of vehicle electrical switch box based on CAN bus

In this paper a new design for the low cost but high expansibility with practical multi-function vehicle electrical switch box is proposed, which uses the microchip company´s PIC18F45K80 as the core. The system components and the overall program are described, focusing on the design and implementation of the software modules. How to combination the CAN bus technology and SAE_J1939 protocol in the vehicle electrical switch box and how to optimization design for harsh environments are both detailed discussed in the paper. Through the joint modulation of hardware and software, the automobile starting and operation parameters, such as fuse state, system voltage, temperature and starting current are real-time monitored. The actual test and operation show that the system has good reliable guarantee for the road safety. At the same time, the vehicle electrical switch box also can effectively prevent the engine damages resulting from the auto circuit fault.