基于单片机的酒精浓度检测仪的设计(附实物图,原理图接线图,仿真

基于单片机的酒精浓度检测仪的设计(附实物图,原理图接线图,仿真程序)(任务书,开题报告,中期检查表,外文翻译,毕业论文13400字)
摘要
本设计实现了对不同浓度酒精的检测和显示，通过适当改进可以用于检测酒后驾车。本文用AT89S51单片机与MQ-3型气体传感器实现了对酒精浓度的测量，并对测量数据进行显示，同时利用LCD液晶显示屏显示浓度数值，在超过允许值时发出报警。
本设计主要研究MQ-3气体传感器技术参数的检测和将它接入到酒精浓度检测模块中；将模拟电压信号放大并驱动蜂鸣器使之报警；将采集到的模拟电压信号通过单片机控制经A/D转换，得到数字电压信号；通过液晶屏显示酒精浓度值。对设计的传感器进行了标定，设计的传感器对酒精气体反应灵敏，能在有效范围内测量它的浓度值。并且在检测低浓度酒精时误差较小，最大误差为8.2%满足设计要求。
本文的特色在于标准的确定。对于流动空气，样品的稳定性和水蒸气的影响，提出了解决方案和验证方法。对不同的区间浓度和电压转换关系做线性化处理，简化了硬件电路的设计。设计的传感器可以检测不同浓度的酒精气体，改进之后对解决酒后驾车事故和特殊场合酒精检测都可以使用。
关键词：单片机 酒精浓度检测仪 设计 实现

Abstract
Different concentrations of alcohol solution are detected and showed in the design. The design can be used to the detection of drunk driving through improvement. In this thesis, the concentration of alcohol can be measured and displayed by using the gas sensor based on AT89S51 MCU and MQ-3. At the same time the concentration is displayed by LCD, and the system allow to alarm in the certain value.
In the thesis Major researches are three points. detecting the technology parameters MQ-3 gas sensor, and connecting it to a testing part of the alcohol gas concentration; Analog voltage signal amplification to drive light-emitting diode light to alarm; conversing the voltage signal through the A/D conversion at the control of the single-chip, obtaining the digital voltage signal; displaying the concentration in the digital tube display module.The designed sensor is calibrated. The design of gas sensor is responsive to the alcohol, can measure concentration in the effective range of its concentration. And in the low concentration of alcohol in the test the error is small with the maximum error 8.2%, meeting requirements of the design.
The characteristics of the thesis are to determine the standard. The solutions and verification methods are proposed about the flow of air samples, the sample stability and water vapor. The conversion between voltage and concentration in different range is treated as linear relationship. The design of sensor can detect different the alcohol gas with different concentration. It plays an important role to solve the drunk-driving accidents and alcohol testing for special occasions after improvement.
Keywords：Single chip microcomputer  The alcohol oncentration detecor  Design Implementation

实物验证  
对于本设计的酒精检测仪，报警值是80mg/L,一般超过20ml/L为酒驾，超过80ml/L为醉酒驾驶。
 

目录
1  绪论    1
1.1  设计背景    1
1.2  气敏传感器的研究现状    1
1.3  设计酒精浓度探测仪的意义    2
1.4  本文主要研究工作    2
2  硬件电路设计与实现    4
2.1  单片机开发流程    4
2.2  硬件系统框图    4
2.3  信号采集电路    5
2.3.1  气体传感器的选择    5
2.3.2  信号采样电路    7
2.4  信号转换电路    8
2.5  显示电路    12
2.6  系统整体电路图    14
3  Protel硬件开发软件    15
3.1  Protel软件组成    15
3.2  PCB板设计    15
4  软件设计    19
4.1  软件流程图    19
4.2  主程序    20
5  下载与调试    28
5.1  USB转串口驱动安装    28
5.2  调试    28
5.3  实物验证    30
结论    31
致谢    32
参考文献    33
附录    34
附录A  仿真图     34
附录B  调试结果    35