基于单片机的车用数字仪表设计论文

毕业设计

基于单片机的车用数字仪表设计与实现Design and Realization of Digital Instrument for Automobile

based on MCU

长春工程学院

摘要

本文以汽车现有电信号为基础，选配了霍尔传感器和数字式温度传感器DS18B20，以单片机AT89S52为核心，研制了一种汽车数字式电子组合仪表。仪表对车速、里程、油量、温度4个参数进行测量和显示。系统利用A/D转换器完成对油量信号的采集，车速脉冲信号由单片机进行处理，并由LED显示。随着汽车技术的发展，特别是近年来全球卫星定位系统（GPS）和在线故障诊断技术在汽车中广泛应用，原有的机械指针汽车仪表显示信息量小、体积大、测量误差大，越来越无法满足使用的需要，数字式的汽车电子仪表成为发展的必然趋势。

关键词

单片机 A/D转换器霍尔传感器 DS18B20 LED

Abstract:

Digital electronic instrument is the inevitable trend. On the base of former electronic signal and appending a speed sensor, the DS18B20 which is a digital temperature sensor, this article designs a digital automobile instrument panel that uses microchip AT89S52 as its core. It completes the measurement and display of four parameters as follow: speed, journey, fuel and temperature. Instrument applies the A/D conversion inside microchip to measure the fuel signal, the microchip deal with the signal of vehicle speed and display the result with LED. With the development of vehicle technology, especially global position system and online fault diagnosis are adopted in automobile broadly. The former mechanism pointer instruments have lots of limitations such as little information, large volume and low measurement precision, and can’t be used well today.

Keyword:microchip A/D conversion speed sensor DS18B20 LED

目录

1 引言 .................................................... - 4 -

2总体方案设计 ............................................ - 5 -

2.1车载仪表的发展 .......................................................................................... - 5 -

2.2 设计内容 ...................................................................................................... - 7 -

2.3方案论证 ...................................................................................................... - 7 -

3 硬件系统设计 ............................................ - 8 -

3.1整体系统 ...................................................................................................... - 8 -

3.2车速里程系统模块 ...................................................................................... - 8 -

3.3温度系统模块 .............................................................................................. - 9 -

3.4油量及A/D转换模块 ................................................................................ - 12 -

3.5显示模块 .................................................................................................... - 14 -

3.7报警模块 .................................................................................................... - 17 -

3.8 主控单元 .................................................................................................... - 17 -

4 软件系统的设计 ......................................... - 22 -

4.1主程序的设计 ............................................................................................ - 22 -

4.2测油量子程序的设计 ................................................................................ - 24 -

4.3测速子程序的设计 .................................................................................... - 25 -

4.4测里程子程序的设计 ................................................................................ - 25 -

4.5测温子程序的设计 .................................................................................... - 26 -

4.6键盘子程序的设计 .................................................................................... - 27 -

4.7显示子程序的设计 .................................................................................... - 28 -

5 软硬件调试 ............................................. - 29 -

5.1硬件调试 .................................................................................................... - 29 -

5.2软件调试 .................................................................................................... - 29 -

5.3软硬联调 .................................................................................................... - 30 -

5.4综合调试 .................................................................................................... - 30 -

6 总结 ................................................... - 31 -

参考文献 .................................................. - 32 -

谢辞 .................................................. - 33 -

附录Ⅰ .................................................. - 34 -