摘  要：近年来，塑料大棚蓬勃发展，已经成为农业生产过程中的关键环节。在南疆地区，由于昼夜温差大、干旱沙漠化的自然气候条件，对于塑料大棚内部温度、湿度等相关因素的检测、控制等需求越来越高。

本课题以 STC89C51单片机为控制核心，以DHT1为主要温湿度采集元器件，设计了一种用于普通塑料大棚的温湿度综合参数显示系统。该系统由控制核心、温湿度检测、显示、控制输出、报警等模块组成，开启系统后，由传感器采集温湿度数据在其内部完成模数转换，并将转换后的数字信号传送给单片机，并与初始设定阈值进行比较，得到数据设定值与测量值的偏差，控制外接设备动作、释放，保持大棚内温湿度在合理的范围内。系统设计经济实用，电路结构简单合理，系统运行稳定可靠，可以满足大部分农户需求，且基本实现对温湿度控制要求。90897

毕业论文关 键 词：传感器，温湿度，单片机，智能控制

Abstract：In recent years, plastic shed of vigorous development has become a key link in the process of agricultural production。 In the southern region of Xinjiang, because of the natural climate conditions of large temperature difference between day and night, drought and desertiftcation, it is control of the increasingly high demand for plastic shed temperature, humidity and other internal factors related to detection。 The mathematical model of temperature and humidity in plastic shed internal established through analysis, The project design a ordinary plastic shed temperature and humidity controller which uses STC89C51 as control core, uses DHT11 as the main temperature and humidity data acquisition components。The hardware part which is composed of module control core, temperature and humidity detection, display,output,alarm。 After open the system, temperature and humidity data collected by the sensor analog-to-digital conversion in its interior, and convert the digital signals to the single chip, and the initial threshold comparison, get the deviation of data set value and the measured value, the control of external equipment action, release, maintain temperature and humidity in shed a reasonable range。 The system is stable and reliable, and can meet the demand of the majority of farmers, and the realization of the basic requirements for temperature and humidity control。

Keywords:Sensor,temperature and humidity,MCU,intelligent control

目  录

    1 绪论 4

    1。1课题的选题背景 4

    1。2课题研究的意义 4

2系统总体方案设计 5

    2。1系统功能分析 5

    2。2系统总体方案 5

3系统硬件设计 6

    3。1系统硬件概述 6

    3。2主控模块设计 6

    3。3DHT11传感器模块设计 8

    3。4液晶显示模块设计 11

    3。5继电器模块设计 12

    3。6阈值设定模块 13

4系统软件设计 14

4。1主程序设计 14

    4。2DH11传感器子程序设计 14