目 录
第 1 章 绪论...............................................................................................................................................1
1.1 酒精测试仪现状和发展趋势 ......................................................................................................1
1.2 酒精浓度检测仪设计的意义 ......................................................................................................1
1.3 研究内容......................................................................................................................................2
1.4 系统总体思路 ..............................................................................................................................2
第 2 章 系统总体方案设计.....................................................................................................................3
2.1 总体设计 ......................................................................................................................................3
2.2 控制模块方案论证.......................................................................................................................3
2.3 显示模块方案论证.......................................................................................................................3
第 3 章 硬件电路设计.............................................................................................................................5
3.1 单片机电路设计 ..........................................................................................................................5
3.1.1 单片机介绍.......................................................................................................................5
3.1.2 STC89C52 的功能特性.....................................................................................................6
3.1.3 STC89C52 的原理说明.....................................................................................................6
3.2 MQ3 气体传感器 .........................................................................................................................7
3.2.1 MQ-3 主要技术指标.........................................................................................................7
3.2.2 MQ-3 结构、外形、测试电路.........................................................................................8
3.2.3 MQ-3 传感器调理电路...................................................................................................10
3.3 电源电路 ....................................................................................................................................11
3.4 ADC0809 ....................................................................................................................................11
3.5 LCD 液晶显示模块....................................................................................................................12
3.5.1 LCD1602 显示模块技术参数.........................................................................................12
3.5.2 LCD602 显示模块功能...................................................................................................13
3.6 发光二极管显示报警电路 ........................................................................................................15
3.7 阈值存储电路.............................................................................................................................16
3.8 系统硬件设计原理图分析 ........................................................................................................16
第 4 章软件系统的设计与实现...............................................................................................................18
4.1 主程序设计 ................................................................................................................................18
4.2 分部分软件设计 ........................................................................................................................19
4.2.1 ADC 程序流程图 ............................................................................................................19
4.2.2 LCD 程序流程图.............................................................................................................20
