毕业设计（论文）-基于89C51单片机的蔬菜大棚自动控制系统.doc

摘要
本次设计是基于89C51单片机的蔬菜大棚自动控制系统,它通过温度、湿度、土壤水分传感器来采集数据。考虑到实际情况,蔬菜大棚内空间大,所以分别采用了4个温度传感器测温度、4个湿度传感器测空气相对湿度、4个湿度传感器测土壤相对湿度,而控制电路则设置了左右两个对称的热风炉、风扇、滴灌器,分别控制固态继电器来实现要求。HD7279采用串行接口方式,同时管理了键盘和LED显示器。为了防止程序跑飞,以及电源故障监控,本设计还采用了X25045芯片设计看门狗电路。同时也设计了上位机与单片机的通信,采用RS485标准。通过这一系列的控制,使其对蔬菜大棚环境进行控制,为植物创造适宜的生长条件,从而使农作物获得高产,提高农业生产的经济效益。
关键词:蔬菜大棚;89C51;传感器;看门狗;通信
Abstract
The design is a vegetable greenhouse control system which is based on 89C51 singlechip, it collects data by temperature, humidity, soil moisture into account the actual situation, greenhouse vegetables, a large space, it has adopted four temperature sensors measuring temperature and 4 humidity sensors measuring relative humidity, 4 humidity sensors measuring soil relative humidity, while the control circuit is set up around two symmetric hot stove, fans, irrigation devices, it achieves the respective requirements by controlling the solid state uses serial interface mode, and manages the keyboard and LED order to prevent the program from running out, and power failure monitoring, the design also uses X25045 chip to design watchdog it designed munication circuit between PC and the singlechip, through RS485 the series of controls on the vegetable greenhouse environment ,it will control the vegetable greenhouse environment to create appropriate growth conditions so that the crops will get high yields and improve the economic efficiency of agricultural production.
Key words: vegetable greenhouse; 89C51; sensor; watchdog; communication
目录
第一章绪论 1
课题研究的技术背景和设计依据 1
国内蔬菜大棚发展的现状和趋势 1
蔬菜大棚内环境因子对植物的影响 2
蔬菜大棚温度控制系统的功能 3
第二章控制系统方案论证 4
控制系统方案选择 4
方案一:模拟电路设计 4
方案二:单片机系统设计 4
系统控制方案的确定 5
第三章系统的硬件设计 6
单片机 6
单片机的选择 6
89C51单片机 6
温度检测电路的设计 8
温度传感器的选择 8
温度传感器DS18B20的介绍 9
温度传感器DS18B20的硬件接线图 10
湿度检测电路的设计 11
湿度传感器的选择 11
湿度传感器SHT11的介绍 11
湿度传感器SHT11的硬件接线图 1