| The CAN (Controller Area Network) is a serial data communication bus developed in the beginning of the nineteen eighties by BOSCH Germany in order to solve the problem of data exchange in the instruments of automobiles. CAN is widely applied in automobile electric, industry control, aerospace and so on industry because of its good characteristics. Now, CAN has been become international standard and is one of the most widely used fieldbus in the world.This paper expounds the development and application actualities of CAN-Bus, and studies the CAN's protocol and characteristics. Meanwhile, combining with the communication characteristics of USB, the CAN Bus data recorder is designed. The recorder is used to monitor the data information from the vehicle CAN on driving vehicle, and stored the monitor information into USB flash disk then transfer the information to computer, the information is read by computer directly and analyzed using software. Besides, the USB interface of recorder can be connected with computer directly in USB-Device mode, to realize the online motoring, display and analysis of the information on CAN. According to the need of analyzing data, the recorder adds the timestamp to each storing CAN message, the accurate of timestamp can reaches 10μs.In the aspect of hardware design, the recorder uses the 16 bit microcontroller MSP430FG4618 as controller centre, the peripheral modules include CAN Bus communication, USB interface, real-time clock, power circuit and other peripheral circuit modules. In the aspect of software realization, using modularization programming in C language, the software of CAN Bus communication, capturing the timestamp of CAN message, data storing and the Device mode of USB interface is achieved. The communication between computer and recorder is realized by using Visual C++ to program computer application software.By testing the recorder system, the results shows that the design of CAN Bus data recorder of the paper studied is correct, the system runs steadily and records data integrity, the desired goal of the system is achieved. |
