The Design On The Slave Control System Of The Auto Repair Vehicle Based On CAN Network

Auto repair vehicle system consists of master-slave automatic control system. This paper describes the design of the slave control system and the draft of its CAN communication protocol.The design and development of the slave control system is based on MSP430F5336 which main function is to process 16 sensor input signals, control output 16 signals drive solenoid or relay to complete repair process,and communicate with the motherboard embedded systems of repair vehicle by the CAN bus.According to the above functional,some hardware and software modules is designed and A Multi byte data communication method is provided based on the MCP2515 CAN controller.Using the arbitration field of the extended data frame, the additional two bytes of data is provided, one of the bytes is used as the destination node number, another byte is used as the command word.The data field length is still 0~8 bytes optionally.MCP2515 provides the bits masks and filters apply to arbitration field in order to choice the destination node No. from the data frame, reducing the overhead of the MCU.At the same time,solving the problem of a CAN node to manage multiple sub nodes.The communication protocol of the slave system is a protocol which includes two functional components. The protocol provides the model of slave system’s physical layer, data link layer(implemented by the MCP2515), the application layer and so on.Finally, according to testing and analysis the system,the test results show the slave system fully meet the design requirements.