基于51单片机的环境监控系统的设计.docx

摘 要

环境和每个人的生活息息相关，环境温湿度是影响人们生活的两个重要因素。目前环

境监控系统大多用于大型生产行业及环境保护方面，对中小型生产及普通生活环境温湿度

的监测重视度相对不足。随着近几年科技产品的爆发，单片机（Microcontrollers）以其低

成本、高性能、小而集成度高的特点得到了快速发展，基于单片机的低成本的环境温湿度

监控系统得到了广泛关注。

本次毕业设计的系统注重性能好、成本低、系统操作简单、适用性广等特点，设计了

基于 51 单片机的环境监控系统。该系统采用 AT89S52 单片机（C51 内核）做为系统的微

控制器，借助温湿度传感器、液晶显示器、蜂鸣器及独立按键等几个外围模块，实现对环

共 2 行，每行可以显示 16 个字符，因此能够同时显示温度和湿度，是一种价格便宜、使

用方便的显示设备；通过四个独立按键，能够自定义温湿度的报警上下限值；蜂鸣器作为

系统的发声报警装置；单片机通过对各个模块的程序调用，实现对环境温湿度的监控。本

文主要介绍了所设计系统的电路原理、软件编写方法和系统仿真，对各个器件做了详细的

原理分析和规格说明，对各个模块的程序编写方法做了详细的流程图，最终，设计出了一

套功能完善环境的系统。由于本系统应用于小型生产活动与日常生活中，因此本系统在设

计时以可靠性高、实时性好、价格便宜、操作简单为原则设计。

本设计根据单片机系统的设计方法和编程原理，编写了完整的系统程序。该系统运行

过程如下：单片机上电后首先执行各模块初始化程序，之后由用户通过四个独立按键对温

度、湿度上下限值设定，单片机判断限值合法后将限值存入自身内部 Flash 存储器，随后

humidity are two vital factors. Recent years, with the explosion of technological products,

Microcontrollers is developed rapidly for its characteristics of low costs, high-performance, small

but high integration; ambient temperature and humidity monitoring alarm system that based on

Microcontrollers is one of the hot research areas. Using Temperature and humidity sensor, LCD

monitor, buzzer and independent keyboard and some other modules this paper designed

environmental monitoring system that based on Microcontrollers.

When it is necessary to monitor ambient temperature and humidity in some small and medium

industry or our normal life, it is often being ignored, because so far, environmental monitoring

system is mostly used by large industry or in environmental protection. The system designed here

can be widely used because of its high-performance, low-cost, simple operation, wide applicability.

easy to use and easy to program and good enough to meet the need of high-performance, low-cost,

simple operation, wide applicability. Temperature and humidity sensor DHT11 can collect

ambient temperature and humidity at the same time and can realize analog-digital conversion and

data transmission by itself. it has the characteristics of high precision and real-time monitoring, it

has 2 lines, 16 characters on each line so it can show the data of both temperature and humidity on

one screen. It is an inexpensive and easy to use display device. Four independent keyboard can set

temperature and humidity alarm to the limits. The buzzer can alarm by itself when the data is over-

limited. By controlling different modules, Microcontrollers realized monitoring ambient

temperature and humidity. The design process is firstly to define Microcontroller’s foot, then

define function keyboard respectively. And software programing the module of the drive. This

low cost, simple circuit, reliable and perfect real-time monitor.

Keywords：AT89S52 Microcontroller; DHT11 sensor; LCD1602; buzzer

目 录

摘 要.......................................................................................................................................III

ABSTRACT .............................................................................................................................IV

目 录........................................................................................................................................V

第 1 章 绪论...............................................................................................................................1

1.1 本课题的研究内容和意义............................................................................................1

1.1.1 内容简介...............................................................................................................1

1.1.2 研究意义...............................................................................................................1

1.2 国内外的发展概况........................................................................................................2

1.2.1 国内发展状况.......................................................................................................2

2.2 系统设计思路与设计原则............................................................................................5

2.2.1 设计思路...............................................................................................................5

2.2.2 设计原则...............................................................................................................5

2.3 系统整体设计................................................................................................................6

2.3.1 系统整体设计框图...............................................................................................6

2.3.2 系统硬件选择.......................................................................................................6

2.3.3 系统工作过程.......................................................................................................7

2.4 本章小结........................................................................................................................7

第 3 章 硬件系统设计...............................................................................................................9

3.1 概述................................................................................................................................9

3.4 LCD1602 液晶显示模块设计......................................................................................13

3.5 报警模块设计..............................................................................................................17

3.6 按键系统设计..............................................................................................................18

3.7 硬件系统整体电路原理图..........................................................................................19

4.2.1 DHT11 温湿度采集模块程序设计 ....................................................................22

4.2.2 LCD1602 液晶显示模块程序设计.....................................................................22

致 谢.......................................................................................................................................31

参考文献...................................................................................................................................33