基于单片机的酒精气体检测系统设计【毕业论文+文献综述+开题报告】.doc

（　2011 届） 毕业设计 题 目： 基于单片机的酒精气体检测系统设计 姓　　名：　　 　　　 专　　业：　　 电子信息工程 班　　级：　　　　基于单片机的酒精气体检测系统设计 摘 要 本文所设计的检测系统可用于对多种场合的酒精气体的浓度检测和显示。系统以AT89C51单片机与MQ-3型气体传感器为核心元件，实现对酒精浓度的检测并显示测量结果。用二极管显示浓度的高低，当浓度达到设定值时报警电路发出警报。 具体毕业设计工作为：硬件系统设计设计了以MQ-3气敏传感器为核心的酒精浓度检测模块将模拟电压信号放大并驱动发光二极管点亮报警的电路将采集到的模拟电压信号A/D转换，通过单片机控制得到数字电压信号的相关电路酒精浓度的数码管显示模块。软件系统设计研究了通过软件手段实现酒精浓度到电压值之间的线性转换、程序以及酒精浓度值的显示程序。本文所设计的传感器对酒精气体反应灵敏，能在有效范围内实现对其浓度的测量。 A/D转换，单片机，酒精浓度测量  Research on SCM based alcohol gas detection system Abstract This paper designed by detection system which can be used on many occasions alcohol gas concentration measurement and display. System to AT89C51 and MQ-3 type gas sensor as the core component of alcohol concentration, to realize the detection and display measured results.Using diode display concentration of discretion, when the concentration of the alarming circuit to setting an alarm. Specific graduation design work for:hardware system design:1,designed to MQ-3 gas sensors as the core of alcohol concentration measurement modules.2,will simulation voltage amplification and drive leds light alarm circuit. 3,will the collected simulation voltage signal after A/D conversion, and then through the single-chip microcomputer control the voltage signal obtained relevant digital circuit. 4,alcohol concentration of digital tube display module.Software system design:through software means alcohol concentration to the voltage value between the linear transformation, A/D conversion program and alcohol chroma value display program. This design sensors to alcohol gas senstive reaction, can realize the effective limits on its concentration measurement. Keywords: Gas sensor, A/D conversion, Single-chip Microcomputer, Alcohol concentration measurement 目录 摘要 III Abstract IV 1 绪论 1 1.1课题的来源、意义 1 1.2酒精气体检测系统国内外发展现状 1 1.3本文研究的主要内容 2 2硬件电路的设计与实现 4 2.1硬件系统框图 4 2.2信号采集电路 4 2.2.1 气体传感器的选择 4 2.2.2 信号采采样电路 6 2.3信号转换电路 7 2.4发光二极管报警电路 11 2.5数码管显示电路 13 2.6系统整体电路图 15 3软