上海电力学院
本科毕业设计（论文）
题 目：院 系：指导教师：
基于单片机的温度测量系统
自动化工程学院
马进明
基于单片机的温度测量系统
【摘 要】
温度测量在实际生产和人们生活中都有广泛应用，为此我设计了一个温度测量系统。本系统利用AT89S52单片机作为主控制器件，DS18B20作为测温传感器通过LED数码管串口实现温度显示，通过按键电路设置上下限报警温度。并且在到达报警温度后，系统会自动报警。本文设计是从测温电路、主控电路、报警电路等几个方面来分析说明的
该系统利用DS18B20测温范围广、测温分辨率高、外围电路简单、功耗低等特点，与AT89S52构成比较简单的测温电路。该系统设计灵活、抗干扰性好，可以在恶劣的工作环境中进行温度测量。
关键字：单片机；温度传感器；温度计；报警
基于单片机的温度测量系统
【Abstract】
.In this design using the AT89S52 microcontroller as the main control device, DS18B20 as an LED digital temperature sensor tube to achieve temperature display. The key circuit sed the temperature to set the alarm on the lower temperature. And the temperature reaching the alarm, the system will automatically alarm. This design is from the temperature measurement circuit, main control circuit, alarm circuit, and several other aspects of the note.
The system uses DS18B20 temperature measurement range, high temperature measurement resolution and peripheral circuit is simple, low power consumption, compared with AT89S52 devices constitute a simple temperature measurement circuit. The system design of flexible, anti-interference performance is good, can be in the poor working environment for temperature measurement.
Keywords：AT89S52；DS18B20；thermometer；alarm
基于单片机的温度测量系统
目录
1 引言........................................................................................................................................... 1
1.1 选题的背景..................................................................................................... 1 1.2 选题的目的及意义......................................................................................... 1
2 系统设计的整体方案 ..................................................................................................... 3
2.1 设计的主要内容............................................................................................. 3 2.2 设计性能要求................................................................................................. 3
3 器件的选择 ........................................................................................................................... 4
3.1 单片机的选择 .............................................................................................................. 4
3.1.1 AT89S52的基本组成及特征 ................................................................................ 4 3.1.2 AT89S52的引脚功能 ............................................................................................ 5 3.1.3 AT89S52的工作模式及注意事项 ........................................................................ 8
3.2 温度传感器的选择 ..................................................................................................... 9
3.2.1 DS18B20的特点及选择原因 ................................................................................ 9 3.2.2 DS18B20的测温原理 .......................................................................................... 11
3.3 显示器的选择............................................................................................... 11 3.4 蜂鸣器........................................................................................................... 12 3.5 排阻............................................................................................................... 13
4 电路原理 .............................................................................................................................. 14
4.1单片机电路 .................................................................................................................. 14
4.1.1 晶振电路 ............................................................................................................. 14
基于单片机的温度测量系统
4.1.2 复位电路 ............................................................................................................. 16
4.2 温度采集电路............................................................................................... 16 4.3 温度显示电路............................................................................................... 17 4.4 温度上下限设置电路................................................................................... 17 4.5 温度过限报警电路....................................................................................... 18 4.6 系统总电路图电路....................................................................................... 19
5 系统流程图 ......................................................................................................................... 20
5.1 主程序........................................................................................................... 20 5.2 读出温度子程序........................................................................................... 21 5.3 温度转换命令子程序................................................................................... 21 5.4 计算温度子程序........................................................................................... 22 5.5显示数据刷新子程序.................................................................................... 22
6 软件仿真 .............................................................................................................................. 24
6．1 软件设计流程............................................................................................ 24 6.2 原理图的绘制............................................................................................... 24 6.3 单片机程序的调试与编译........................................................................... 26 6.4 仿真过程....................................................................................................... 27
7 总结......................................................................................................................................... 28
7.1 设计总结....................................................................................................... 28 7.2 设计前景....................................................................................................... 28
8 致谢 ................................................................................................... 30 参考文献 ............................................................................................... 31