实验室温湿度监控系统的设计
摘 要
本文主要介绍了温湿度的检测，包括温度传感器、湿度传感器、单片机接口及其应用软件的设计，大体分为以下几大部分：介绍了国内外温湿度检测及监控技术，并且分析了温度检测及监控技术的未来发展方向。
本系统是基于复合式温湿度传感器SHT11、单片机AT89C51 对温度湿度分别测量并通过液晶显示屏1602经行显示。本系统由上位机和下位机构成，下位机主要完成温湿度的采集与处理，将其传至1602液晶显示，并做出判断实现超限报警。同时，下位机还通过 RS232 总线将温湿度数据传至上位机，上位机可实时显示当前的温度与湿度值。本系统具有可读性高，稳定性高，反应速度快，测量值准确的特点。该系统电路简单、工作稳定、集成度高,测试精度高,具有一定的实用价值。
温湿度检测是以8051单片机系统和温湿度相结合的温度测量系统。本系统的数学模型合理，测量方法容易实现。实际仪器采用抗干扰、零漂、低温漂的电子元件，性能稳定。该测量仪总体特点是使用简便、实用、使用对象广、并且实现了自动化。
关键词：温度测量；湿度测量；数据采集；单片机
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：实验室温湿度监控系统的设计
The Design of Temperature and Humidity Monitoring
System in Laboratory
Abstract
In this paper, including temperature and humidity testing, temperature sensors, humidity sensors, microcontroller interfaces and application software design. It can be divided into the following parts: introduction of temperature and humidity detection technology at home and abroad, and analysis of the future of temperature measurement technologies development.
The system is based on the combined temperature and humidity sensor SHT11, monolithic integrated circuit AT89C51 surveys separately to the temperature humidity and demonstrated through the liquid crystal display monitor 1602 silk thread business. This system consists of upper and lower body, slave machine is complete the acquisition and processing of temperature and humidity, then pass them to the 1602 LCD display, and judge the ultra limit alarm. At the same time, lower computer through RS232 bus is rumored to first degree temperature and humidity machine, PC can show the current temperature and humidity values. This system has a high readability, high stability, reaction speed, measurement accuracy of characteristics. The circuit is simple, stable and high integration of the system, high accuracy, have practical value.
Temperature and humidity detection system is base on 8051 the combination of temperature and humidity, the temperature measurement system. The system mathematical model is reasonable, easy measurement. The actual instruments used anti-interference, low zero-drift, low temperature drift of electronic components, performance and stability. The general characteristics of measuring instrument are easy to use, practical, widely used object and automated.
Keywords: Temperature Measurement；Humidity measurement；Data Acquisition；Single-chip Microcomputer
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：实验室温湿度监控系统的设计
目录
引言 ............................................................................................................................................ 1 第1章 绪 论 ...................................................................................................................... 2 1.1课题研究的目的及意义 ...................................................................................................... 2 1.2国内外测温湿技术及其发展趋势 ...................................................................................... 2 第2章 系统总体方案设计与选择论证 .................................................................................. 4 2.1 系统主要单元的选择与论证 ............................................................................................. 4 2.2系统总体原理框图 .............................................................................................................. 4 第3章 系统的硬件设计 ........................................................................................................ 5 3.1 单片机AT89C51简介 ...................................................................................................... 5 3.2 AT89C51引脚及介绍 .......................................................................................................... 5 3.3 SHT11 传感器 ..................................................................................................................... 7
3.3.1 SHT11 传感器简介 .................................................................................................... 7 3.3.2 SHT11 传感器内部结构及工作原理 ........................................................................ 7 3.4 显示模块 ............................................................................................................................. 9
3.4.1 1602液晶简介 ............................................................................................................ 9 3.4.2 1602液晶与AT89C51接口电路 ............................................................................... 9 3.5键盘电路设计 .................................................................................................................... 10
3.5.1键盘控制电路 ........................................................................................................... 10 3.5.2 各功能键作用分配 .................................................................................................. 10 3.6蜂鸣器电路的设计 ............................................................................................................ 11
3.6.1 报警模块的选择 ...................................................................................................... 11 3.6.2 本设计蜂鸣器工作原理 .......................................................................................... 11 3.7时钟与复位电路的设计 .................................................................................................... 12 3.8单片机与上位机通讯电路设计 ........................................................................................ 12
3.8.1 RS-232C简介 ........................................................................................................... 13 3.8.2 MAX232简介 ......................................................................................... 13 第4章 系统软件设计 ............................................................................................................ 15
4.1 系统软件总体设计 ................................................................................................... 15 4.2 主程序设计 ............................................................................................................... 15 4.3 数据采集及处理子程序设计 ................................................................................... 17 4.4 键盘/液晶显示程序设计 .......................................................................................... 17 结论与展望 .............................................................................................................................. 20 致谢 .......................................................................................................................................... 21 参考文献 .................................................................................................................................. 22 附录A温湿度检测系统仿真图 ............................................................................................. 23 附录B外文文献及译文 ......................................................................................................... 24 附录C 主要参考文献的题录及摘要 .................................................................................... 30 附录D 系统源程序 ................................................................................................................ 32
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：实验室温湿度监控系统的设计
插图清单
图2-1系统总体原理框图…….............................................................................................4 图3-1 AT89C51引脚图.........................................................................................................5 图3-4 SHT11内部原理图…….............................................................................................8 图3-5 1602液晶与AT89C51接口电路……........................................................................10 图3-6键盘控制电路…….....................................................................................................11 图3-7三极管驱动的蜂鸣音报警电路…........................................................................….12 图3-8时钟电路图.................................................................................................................12 图3-9复位电路.....................................................................................................................12 图3-9 MAX232芯片控制电路…….....................................................................................14 图4-4液晶显示流程图…….................................................................................................17
表格清单
表3-3 P3口的第二功能...................................................................................................6 表3-4SHT11的命令代码.......................................................................................…......8
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