天津职业技术师范大学
Tianjin University of Technology and Education
毕 业 设 计
专 业： 微电子学 班级学号： 0801-20 学生姓名： 周美南
指导教师： 裴志军 教授
二○一二 年 六 月
天津职业技术师范大学本科生毕业设计
仓库的四路温度监测与报警系统
Four Channel Temperature Monitor And Alarming System of the Warehouse
专业班级：微电0801
学生姓名：周美南
指导教师：裴志军 教授 系 别：电子工程学院
2012年6月
摘 要
目前，我国各种大型粮库存在着不同程度的粮食变质问题，人工测温方法工作效率低。因此，借助数字温度采集芯片的处理能力，实施对温度的实时监控，对降低生产安全因素，提高劳动效率，改善生产环境有很重要的积极作用。
仓库的四路温度监测与报警系统以AT89S51为核心，本系统的采集对象是温度，因此系统设计包括：温度采集模块、数据存储模块、温度转化模块、温度显示模块、复位模块、供电系统等几个基本部分。前向通道包括电源、四路DS18B20传感器输入和按键复位电路。后向通道包括在线编程端口和LED显示电路。电源给整个系统提供4～5.5V的直流电流。温度传感器将分散于各数据点的温度数据转化为数字信号送入单片机内寄存器待处理。一个复位按键用来对整个系统进行跳出复位，防止程序进入死循环。LED数码管作为当前通道代码及该通道温度值的显示设备串口可以实现在线系统编程。
最终，通过硬件设计和软件仿真实现了设计功能。
关键词：温度采集；DS18B20；AT89S51单片机；数据监测
I
ABSTRACT
At present, China's large grain storage exists with varying degrees of food quality deterioration, low efficiency of manual temperature method. With digital temperature acquisition chip processing capabilities, the implementation of real-time monitoring of temperature, a very important positive role in reducing the factors of production safety, improve labor efficiency, and improve the production environment.
Four temperature monitoring and alarm system of the warehouse AT89S51 collection of objects of the system temperature, system design should include: temperature acquisition module, data storage module, temperature conversion module, temperature display module, reset the module, power supply systems few basic parts. Prior to the channel, including power supply, four DS18B20 sensor input and button reset circuit. After the channel, including online programming port and the LED display circuit. Power supply provides a 4 to 5.5V DC to the entire system. The temperature sensor will be distributed at the data points of temperature data register to be processed into a digital signal into the microcontroller. A reset button is used to the whole system out of reset, to prevent the program into an infinite loop. LED digital tube as the current channel code and the channel temperature of the display device can be achieved online system programming.
In the end, hardware design and software simulation design.
Key Words：Temperature acquisition; the DS18B20; AT89S51 MCU; data monitoring
II
1
目 录
引言 ............................................................................................ 1
1.1 1.2
温度采集的发展现状 ..................................................................... 1 温度采集系统的目的及意义 ......................................................... 1
2 3
系统原理 .................................................................................... 2 系统方案论证及选择 ................................................................ 3
3.1 3.2 3.3
传感器的选择 ................................................................................. 3 单片机的选择 ................................................................................. 3 DS18B20 ......................................................................................... 4 3.3.1 DS18B20的性能特点 .............................................................. 5 3.3.2 DS18B20的外形和内部结构 .................................................. 5 3.3.3 DS18B20的工作原理 .............................................................. 6 3.3.4 DS18B20的操作 ...................................................................... 7 3.4
AT89S51 ........................................................................................ 11 3.4.1 AT89S51功能介绍 ................................................................. 11 3.4.2 AT89S51单片机的内部结构................................................. 11 3.4.3 AT89S51芯片的引脚及特点................................................. 12 3.4.4 AT89S51的主要性能参数 ..................................................... 16 3.4.5 AT89S51的新功能 ................................................................. 16
4 硬件设计 .................................................................................. 17
4.1 4.2 4.3 4.4
晶振电路 ....................................................................................... 17 复位电路 ....................................................................................... 17 电源稳压电路 ............................................................................... 18 程序下载电路 ............................................................................... 18