The Research And Design Of Automobile Combined Instrument Based On CAN-bus

With the fast developing about automobile electric technology, the advanced communication-network technology CAN-Bus is used in the designing of automobile instrument panel (IP), and takes place of the traditional mechanical and electrical design. The automobile BUS-IP use two wires to communicate with the other CAN node, realize the resource using in common among the ECU. It has become the dominant technology in the future time.The content of thesis divides into hardware and software. Use CAN signal to communicate between the power and driving system, use on-off circuit to control the automobile body information. At first, the article analyzes the demand about the all function, and constructs the function structure chart.The whole system takes MC9S12H128 as core MCU, which is a quick high-capability 16-bit MCU produced by Freescale Company. Embedded Function model MSCAN receive and transmit the CAN signal, and the A/D model realize analog to digital converter, TIM model gather and take count of the pulse number, SPI circuit exchange the data with the exterior circuit, and so on. At the same time, the system adopt LED take place of the lamp, use step-motor display the meter data more exactly, take LCD display as a multifunction window, through changing page, dividing screen and modify the program can display more information directly.On the software designing, analyze the scheme and program flow about CAN communication in details. And the same time, complete the program flow about impulse signal gathering, the process flow about the A/D task and the step-motor driving circuit.The last, analyze and design the way and the measure to resist the disturb resource.Compare with other projects, the system has the following features: high embedded degree, stable performace capbality and the cheap price for the whole system.