目录引言.............................................................................................................................................31功能要求…………………………………………………………..…………………...……42系统方案论证与比较………………………………………………..……..…………….…42.1数字温度计设计方案论证…………………………………………..…………………...42.1.1方案一……....………………..………………………………………………….…..42.1.2方案二…....……….…………………………………….…………...………..…......62.2方案二的总体设计框图………………………………………….……………..………..73系统主要元器件的选择及介绍.............................................................................................83.1单片机的选用及功能介绍…..…………………………….….……………..…….…….83.1.1单片机简介.................................................................................................................83.1.2单片机的产生与发展……………………………….……………...………..…...…93.1.3单片机的应用……………………………………….………………..…..………..103.1.4MCS-51单片机引脚及功能介绍..............................................................................113.2温度传感器的选择…………..………………………….………..……………..……...133.2.1DS18B20简单介绍………………………………….……..………………..….…..143.2.2DS18B20的性能特点和使用中的注意事项……….…..…………………..….…..143.2.3DS18B20的引脚及内部结构………………………...………………………...…..163.2.4DS18B20的工作原理…………………………………….……………….……....253.2.5DS18B20的单线协议和命令…………………....………….………….……........263.2.6温度数据的计算处理方法……………………...………………………….…........294系统硬件电路的设计…………………………….………..................................................324.1主板电路...........................................................................................................................324.2显示电路………………………………………………………………….……….…….324.3DS18B20温度传感器与单片机的接口电路…………………………….…….………..335系统软件算法分析………………………………………………………………..………..345.1主程序…………………………………………………………………………………...345.2读出温度子程序………………………………………………………..……………….355.3温度转换命令子程序………………………………………………….…….………….365.4计算温度子程序…………………………………………………………..…………….375.5显示数据刷新子程序…………………………………………………………..……….386调试及性能分析………………………………………………………………..………….39结论…………………………………………………………………………..……………….40致谢………………………………………………………………………………..………….41参考文献…………………………………………………………………………..………….42附录………………………………………………………………