摘 要：酒后驾车是导致交通事故的一个主要因素，因而酒精浓度测试仪得到了广泛的关注与应用。本文设计了一种以AT89C51单片机为核心的酒精浓度测试仪，主要模块包括单片机最小系统、A/D 转换电路、传感器电路、液晶显示电路、键盘电路和声光报警电路。MQ-3气敏传感器将检测到的酒精浓度转化为电信号，A/D 转换器将输入的电信号转化为数字信号，单片机对所输入的数字信号进行运算处理，最后将结果显示在LCD显示屏上，并根据是否超过报警值发出对应的声光信号。利用Keil编程软件进行编程并调试，接着使用Proteus仿真软件进行仿真调试。然后根据原理图选择元器件，再通过电路板的焊接、程序的烧录和调试等过程完成制作酒精浓度测试仪。经试验，实物可以准确地测量出酒精浓度值并发出准确的声光信号。65373

毕业论文关键词: 酒精浓度测试仪，MQ-3气敏传感器，AT89C51单片机

Abstract:Drunk driving is a major factor in traffic accident, so alcohol concentration tester has been widely concerned and applied. This paper designs a AT89C51 micro controller as the core of the alcohol concentration tester. The module mainly includes MCU minimum system, A/D conversion circuit, sensor circuit, LCD display circuit, keyboard circuit and sound and light alarm circuit. That MQ-3 gas sensors transforms alcohol concentration into electrical signals, and A/D converter converts input signal conversion into digital signal. Micro controller processes input digital signal. Finally, the results are shown on the LCD display. And according to whether exceeds the alarm value, the corresponding sound and light signals are issued. Program and debug with Keil programming software. Then simulate and debug with Proteus simulation software. The components are selected according to the simulation diagram. And alcohol concentration tester can be completed through the circuit board welding, the burning process and the process of debugging. The test shows that alcohol concentration tester can accurately measure the alcohol concentration value and send out accurate light and sound signals.

Keywords: alcohol concentration tester, MQ-3 gas sensor, AT89C51 micro controller

目   录

1 绪论 2

1.1 本文研究背景 3

1.2 酒精浓度测试仪的研究现状 3

1.3 本文研究内容 3

2 酒精浓度测试仪总体方案和硬件设计 4

2.1 酒精浓度检测仪的功能要求 4

2.2系统结构及总电路图设计 4

2.3单片机最小系统及设计 7

2.4声光报警电路 10

2.5 MQ-3气敏传感器 11

2.6 A/D转换电路 12

2.7显示电路 13

3 酒精浓度测试仪软件设计 15

3.1 主程序的设计 15

3.2 数据采集子程序程序框图 19

3.3显示程序设计 20

4 仿真 20

4.1原理图的绘制 20

4.2程序的录入 21

4.3仿真过程 22

5 实验 23

5.1 调试