Design Of Automobile Instrument System Based On MC68HC908LJ12

Automotive dashboard is the most important and direct visible information platform for a driver. It plays a crucial role in driving safely. Automotive dashboard is one of important parts of motor vehicles, and it will be targeted, directly and quickly reflect the vehicle in motion a variety of dynamic index. Dashboard will become an important criterion for measuring the performance and excellence of automobiles.The principle of how to measure the main automobile running parameters is first discussed in this paper and the correlative math model is given. According to the status in our country, a development program based on MC68HC908LJ12 of Freescale's MCU has been proposed. The content of thesis divides into hardware and software. At first, the article analyzes the demand about the all function, and constructs the function structure chart, the function of modular structure for each module in detail. Ultimately all-digital instrumentation stepper motor vehicle assembly, the instrument has a stepper motor system instrumentation, LCD, LED and other display features to the car speed, engine speed, water temperature, fuel quantity, and several other parameters remaining real-time measurement. Finally, the design and implementation of the system is tested prove the interpretation of the provisions of the national standard.Compare with other projects,the system has the following features, high embedded degree, stable performance capability and the cheap price for the whole system. In order to expand system function, there are more switching modules and stepping motor modules to be set.