Research On The Combined Instrument Of Automobile Based On CAN BUS

The instrument of automobile is the main interface through which the driver can commute message with the automobile and the safely and economically running of the automobile is greatly influenced by it. Recently, with automobile electronical technology development, the traditional mechanical assembled instrument can no longer satisfy need more and more. Especially with the widely using of computer, micro-electronics and field bus communication technology, intelligent instrument based on microprocessor is the necessary trend of automobile instrument development.Under the study of the instrument of aptitude digital automobile at home and abroad, an advanced multi-functional security monitoring system for car is developed, which takes advantage of the technology progress in the fields such as electronic, computer, sensor and controlling. The system not only possesses LCD interface to report parameter, but also performs the general functions such as automobile running recorder, clock chip, serial communication, and stepping motor control functions.To perfect the function of the system, improve the advances, and guaranty the credibility, CAN bus is adopted, which makes it possible for users to add units (CAN monitoring module) dynamically to meet different needs, without the least changes of the system's hardware. The monitoring system is made up of one S3C44B0X main controlling unit, and four smallest units. The smallest unit is to sample signals, perform A/D function, and send them to the main unit using CAN bus. Finished processing the received data, the main unit displays the result, the controlling unit sends out controlling signals.The software is based upon present fashion and free mac OSμC/OS-Ⅱthat is based on the programming technology of multitask system and it brings forward the settling scheme of the instrument of automobile software with the mac OSμC/OS-ⅡandμC/OS-Ⅱ's transplanting S3C44B0X. The digitized measured parameters is in favor of commuting data with other electrical control systems and automobile control system's development and realization, which makes the instrument of automobile have a low cost, high reliability, comfort, expanding system function and improving wiring harness. Through amending system's parameter, the system's performance and measure can be change with clients' need. By amending system's parameter, it can make automobile instrument adapt all kinds of need on kind and range, which can development automobile technology in general using, modularization, standardization and series, consequently predigesting producing arts and crafts and manufacture equipment.Finally, the instrument combining S3C44B0X and embedded mac OSμC/OS-Ⅱachieves the instrument of aptitude digital automobile that is based on CAN bus and it achieves entirety protocol with other electrical control systems, and also the correlative basal knowledge of the hardware and software of the main unit and smallest unit are discussed, and some key sections are analyzed in detail.