基于DHT的温湿度监测电路设计详解.doc

题目：基于DHT11的温湿度监测电路设计 基于DHT11的温湿度监测电路设计 摘 要 本次设计是采用MSC-51系列单片机中的AT8951和DHT11构成的低成本的温湿度的检测控制系统。单片机、温湿度传感器、显示模块、报警器以及等部分由温湿度传感器及字符型液晶模块构  DHT11 Temperature and Humidity monitoring circuit design ABSTRACT AT89S51 is a low consumption, high performance CMOS8 bit microcontroller.Because of its powerful features and low price, it is used in many areas.DHT11 temperature and humidity sensor is a temperature and humidity combined sensor containing a calibrated digital output, the sensor consists of a resistor in the original sense of wet and a NTC temperature measurement devices.The product has many advantages, such as excellent quality, fast response, strong anti-jamming capability . This design is fromed by the AT89S51 in MSC-51 Series and DHT11 constitute which is a low-cost temperature and humidity measurement and control system. The design includes the design of hardware circuit design and system software. The hardware has Five modules.They are a microcontroller, temperature and humidity sensors, display module, alarm and control equipment. The LCD1602-character LCD module constitute the system display module.The temperature and humidity control circuit by the temperature and humidity sensors and preset temperature alarm circuit.According to the need of pre-enter the default value, when the actual measurement of the temperature humidity does not conform the preset temperature and humidity standards, send the alarm signal (buzzer will beep). The software part includes the main program, the display routines, temperature and humidity subroutine. Key words： AT89S51 ；DHT11 ；Temperature and humidity monitoring. 目 录 1 前 言 1 1.1 本文研究的背景及意义 1 1.2 研究任务和主要内容 1 1.2.1 本系统要完成任务 1 1.2.2 主要内容 1 2 设计任务要求分析 2 2.1 设计要求 2 2.2 系统组成 2 2.3 本章小结 2 3 硬件设计 3 3.1 单片机模块设计 3 3.1.1 AT89S51单片机 3 3.1.2 单片机最小系统 4 3.1.3 复位电路 4 3.1.4 时钟电路 5 3.1.5 温湿度设置（按键）电路 6 3.2 显示电路 6 3.3 传感器电路 8 3.4 电源指示灯电路 10 3.5 系统的蜂鸣器电路 10 3.6