基于DHT11的温湿度监测电路设计..

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AT89S51和DHT11构成的低成本的温湿度的检测控制系统。单片机AT89S51是一款低消耗、高性能的CMOS8位单片机，由于它强大的功能和低价位，因此在很多领域得到广泛应用。DHT11温湿度传感器是一款含有已校准数字输出的温湿度复合传感器，传感器包括一个电阻式感湿原件和一个NTC 测温元件，该产品具有品质卓越、超快响应、抗干扰能力强、性价比极高等优点。设计主要包括硬件电路的设计和系统软件的设计。

硬件电路主要包括单片机、温湿度传感器、显示模块、报警器以及控制设备等五部分。其中由DHT11温湿度传感器及LCD1602字符型液晶模块构成系统显示模块；测温湿度控制电路由温湿度传感器和预设温度值比较报警电路组成；用户根据需要预先输入预设值，当实际测量的温湿度不符合预设的温湿度标准时，发出报警信号（蜂鸣器蜂鸣）。

软件部分包括了主程序、显示子程序、测温湿度子程序。

关键词：AT89S51；DHT11；温湿度监测

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)

3.1.1AT89S51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本章小结 (11)

4软件设计 (12)

4.1温湿度采集模块 (14)

4.2显示模块 (15)

4.3蜂鸣器报警模块 (15)

4.4PROTUES运行结果 (16)

4.5本章小结 (17)

结论 (18)

参考文献 (19)

致谢 (20)