汽车胎压监测系统设计

大学泉城学院

毕业设计

题目汽车胎压监测系统设计

学院工学院

专业机械设计制造及其自动化（专升本）班级1501班

学生立兵

学号2015040113

指导教师兴达武华

二〇一七年五月十六日

摘要

随着时代发展和科技进步汽车已成为了人们常用的且离不开的交通工具。随着汽车数量的增多交通事故发生的数量也越来越多，而其中汽车轮胎压力异常成为重要诱因。针对这一问题，本文提出了一种基于单片机的汽车胎压监测系统。实现了测试汽车轮胎压力的功能，由三种不同的计量单位通过LCD显示给用户，如果超出预设阈值就会发出警报提醒司机安全行驶。

本设计主要包含硬件设计与软件设计两部分。硬件部分主要包含气压传感器BMP085、STC89C52单片机和1602LCD等。通过气压传感器BMP085获取与汽车胎压相对的模拟电压值，经过V/F变换输入到单片机进行处理，最终由通过LCD显示电路显示相应气压值。软件部分采用C语言作为开发工具软件，在Keil C环境下进行了对单片机各个端口以及定时器工作方式和串行口工作方式进行设置，并对定时器和串行口进行初始化用以实现对单片机和各个功能模块芯片之间通讯和联络的设定，以及分配地址空间交代程序中各个变量等的设计和编码。

通过软件仿真及实物之作运行调试，完成了系统的可靠性、稳定性等性能的测试，实现了预期功能，为进一步研究及应用提供了一定的数据参考。

关键词：单片机；传感器；胎压

ABSTRACT

With the development of the times and the progress of science and technology, the automobile has become a common and indispensable means of transportation. With the increase of the number of cars, the number of traffic accidents is increasing, and the abnormal tire pressure becomes an important incentive. To solve this problem, a monitoring system of automobile tire pressure based on single chip microcomputer is presented in this paper. The function of testing the tire pressure of the automobile is realized. The three different measuring units are displayed through the LCD to the user. If the preset threshold is exceeded, the alarm will be sent to remind the driver to drive safely.

This design mainly includes two parts: hardware design and software design. The hardware part mainly includes the barometric pressure sensor, BMP085, STC89C52 monolithic integrated circuit and 1602LCD and so on. The analog voltage value relative

to the tire pressure is obtained by the pressure sensor BMP085, which is input to the MCU by the V/F transformation, and finally the corresponding barometric value is displayed by the LCD display circuit. The software adopts C language as software development tools, in the Keil C environment for setting up the MCU port and timer working mode and serial port mode, and the timer and serial port in order to achieve between the microcontroller and the functional modules of the chip communication and contact setting initialization, design and encoding and distribution address space program variables such as account.

Through the software simulation and the debugging of the object, the system's reliability, stability and other performance tests are completed, and the expected function is achieved. It provides a certain data reference for further research and application.

Keywords: pressure sensor; tire pressure; MCU

目录

摘要 ......................................................................................................................... I ABSTRACT .............................................................................................................. II 1前言.. (1)

1.1研究背景及意义 (1)

1.2国外研究和发展的概况 (1)

1.3本设计容 (3)

2系统总体设计 (5)

2.1总体设计思路 (5)

2.2软硬件设计方案 (7)

2.2.1硬件部分 (7)

2.2.2软件部分 (8)

3 系统的硬件设计 (9)

3.1硬件设计思路 (9)

3.2单片机最小系统 (10)

3.2.1晶振电路 (11)

3.2.2供电电路 (12)

3.2.3复位电路 (13)

3.3信号采集电路 (14)

3.3.1无线模块 (14)

3.3.2传感器电路 (15)

3.4电源转换电路 (17)

3.5显示电路 (18)

3.6按键输入电路 (21)

3.7报警电路 (22)

4 系统的软件设计 (24)

4.1软件设计思路 (24)

4.1.1如何由频率计算出气压值 (24)

4.1.2软件设计功能及重要的说明 (24)

4.2程序流程图 (26)

4.3程序实现及调试 (29)

4.4系统仿真及调试 (30)