摘要:该温湿度检测仪是基于单片机AT89S51所设计，并能准确完成对空气中温湿度的检测。硬件部分，湿度的测量由湿敏电阻完成，并由AD0809作为AD转换对湿敏电阻两端的电压进行采集。温度的测量由DS18B20直接完成，并由单片机处理，得到相应的温湿度的值。本装置还加入了报警系统，由蜂鸣器实现，用户可设定温湿度的上下限，一旦超限，蜂鸣器便会报警。LCD1602和数码管各作为湿度和温度的显示装置。软件部分，采用分模块设计的方法，将温度和湿度的显示分成两个模块，用C语言完成，并使之协调合作，完成温室度的检测。

关键词：AT89S51单片机; A/D转换器; 温度传感器; LCD1602;

Abstract:The temperature and humidity detector is based on AT89S51 ,it can be real-time, accurate measurement of environmental temperature and relative humidity. As the hardware part,humidity measurement by wet sensitive resistance to complete,and the AD0809 as AD transform to moisture sensitive resistance on both ends of the voltage are collected.temperature measurement is complete by DS18B20 temperature probe,single chip processing, get the corresponding temperature and humidity value.The device add an alarm,it can set range.if temprature and humidity over limit it will alarming.Iuse LCD1602 to display humidity and temperature.AsThe software part ,I use the method of module design points,the temperature and humidity display is divided into two modules,with C language to achieve,to combine the various parts of coordination, and eventually realize the environmental temperature and humidity in the real-time detection. 

Key words: AT89S51 MCU; A/D conversion; Temperature sensor;  LCD1602;