目 录摘要......................................................................IAbstract.................................................................II第 1 章 绪论...............................................................11.1 课题的背景和意义...................................................11.2 课题基本任务及要求.................................................21.3 本课题的主要工作...................................................2第 2 章 硬件设计...........................................................32.1 总体方案设计.......................................................32.2 AT89C52 单片机特点及功能...........................................42.2.1 单片机应用系统设计方法.......................................72.3 网络串行通讯总线标准及其接口串行通讯接口...........................72.3.1 RS-485 总线标准接口...........................................82.4 SHTxx 系列数字式传感器.............................................92.4.1 SHT11 传感器的基本工作原理...................................102.4.2 SHT11 的性能指标.............................................102.4.3 SHT11 的引脚和内部构成.......................................102.4.4 SHT11 的典型应用电路........................................122.4.5 SHT11 的数据测量和控制.......................................132.5 硬件电路设计......................................................152.5.1 硬件设计系统框图................................................162.5.2 单片机与 SHT11 传感器的接口设计..................................162.5.3 人机接口电路设计................................................172.5.3.1 键盘部分..................................................172.5.3.2 LED 显示电路...............................................182.5.4 温湿度控制电路及报警电路设计....................................202.5.5 RS-485 接口电路.................................................23第 3 章 程序设计..........................................................253.1 主程序流程...
