摘 要：对于温室大棚，温湿度是影响它发展的环境因素之一。温湿度的或高或低都会致使种植物萎谢、死亡，适宜的温湿度才有利于种植物的健康生长。因此，设计了一种基于AT89C51单片机的大棚温湿度自动控制系统。本系统采用数字传感器DHT11多点检测大棚里的温湿度，并将测量值输送到单片机内部进行存储和处理，处理结果由1602LCD液晶显示屏显示出来，且当温湿度值超过或低于预设的适宜值时，声光报警器将启动，并通过固态继电器打开或断开相应的执行机构进行调整，使大棚温湿度保持在适宜范围内。该设计系统可以全面、实时、自动地对现场环境进行监测，进而实现农业的自动化。94497

另外，该设计除了能显示温湿度值优点以外，还能预先设置温湿度报警阀值，以便适应不同大棚温湿度值的使用。

毕业论文关 键 词：温室大棚，温湿度，单片机AT89C51，自动控制，传感器DHT11，1602LCD液晶显示器

Abstract: For greenhouses, temperature and humidity is one of the environmental factors affecting the development of it。Temperature and humidity of high or low will cause plant fade, death, suitable temperature and humidity is beneficial to the health of the plants to grow。 Therefore, to design a kind of greenhouse temperature and humidity automatic control system based on AT89C51。This system USES the digital sensor DHT11multi-point detection of temperature and humidity in greenhouses, and measurements to the single chip microcomputer internal storage and processing, the processing result by 1602 LCD screen display, and when the appropriate temperature and humidity value exceeds or is lower than the preset value, the sound and light alarm will start, and through solid state relay on or disconnect to adjust the corresponding actuator, keep the greenhouse temperature and humidity in the appropriate range。The designed system can be comprehensive ,real -time and automatically to the site environment monitoring,and thus realize the automation of agriculture。 

In addition, the design temperature and humidity value is displayed in addition to the advantages, also can preset temperature and humidity alarm thresholds, in order to adapt to the use of different canopy temperature and humidity value。

Keywords:greenhouse,temperature and humidity,microcontrollerAT89C51,automatic control, LED digital display

目录

1 绪论 3

1。1引 言 3

1。2选题的背景及意义 3

1。3选题的思路 4

1。4设计的主要内容 4

2 课题硬件电路的分析与设计 5

2。1系统设计的原则 5

2。2系统总体的设计结构 6

2。3单片机的选择 6

2。4温湿度测控设计方案 10

2。5 1602液晶显示模块设计 11

2。6阈值设置模块 15

2。7报警模块 15

2。8控制电路设计方案 16

2。9其他的外围电路设计方案 17

3 课题软件电路的分析与设计 18

3。1传感器模块设计 19

3。2液晶显示器模块设计 20

4 系统分析与测试 21