粮食烘干自动控制系统研究与设计
摘要：多年以来，粮食因潮湿而损失的量不计其数，给国家带来了巨大损失。本课题设计的是一种能够实现粮食自动烘干控制的一体化系统。可实现粮食的湿度、温度的实时监测以及自动脱湿，并能够自动报警。当粮食的温湿度完全符合存储标准后再进行安全存储。
整个系统采用模块化思想，即采用由HS1101电容式湿度传感器与555定时器组成的湿度检测模块、由数字型DS18B20温度传感器组成的温度检测模块、由电磁继电器和热风炉以及组成的烘干模块、由L298N和风扇组成的除湿模块等设计，在主控芯片STC89C52分配下，每个模块都能准确的完成自己的任务。于此同时，由STC89C52及各个模块组成的下位机同过MAX232进行串口通信，将粮食自动烘干的实时数据传输到上位机，以便进行远程实时监测。
本课题的研究解决了粮食烘干智能化问题，粮食的湿度以及烘干炉的温度能够实时的进行远程监测。当温度高于设定值时，系统自动报警并切断热风炉供电，控制风扇处于散热功能。当湿度高于设定值时，切断热风炉供电，控制风扇处于除湿功能。
关键字：STC89C52单片机;温度传感器;湿度传感器;MAX232
Research and Design of Grain Drying Automatic Control System
Abstract： Over the years, the amount of food due to moisture loss of countless, has brought huge losses to the country. The design of this subject is a kind of integrated system which can realize the automatic control of grain drying. It can realize the real-time monitoring of the humidity and temperature of grain, it can automatically take off the wet, and can automatically alarm. When the temperature and humidity of grain is in full compliance with the storage standard, then the safety storage.
The system adopts the idea of modular, namely the humidity detection module is composed of a capacitive humidity sensor HS1101 and 555 timer, composed of digital temperature sensor DS18B20 temperature detection module, by the design of the electromagnetic relay and hot blast stove and composed of drying module, composed by L298N and fan dehumidification module, in the main control chip STC89C52 distribution, each module can accurately complete their task. At the same time, by the STC89C52 and the various modules of the next bit machine with the MAX232 serial communication, the grain automatic drying of real-time data transmission to the host computer, in order to carry out real-time remote monitoring.
The research solved the problem of intelligent grain drying, the humidity of grain and the temperature of the drying oven can be monitored in real time. When the temperature is higher than the set value, the system automatically alarm and cut off the power supply of the hot blast stove, the control fan is in the heat radiation function. When the humidity is higher than the set value, the power supply of the hot air stove is cut off, and the control fan is in the function of the desiccant.
Keywords：STC89C52 single chip ,temperature sensor ,humidity sensor ,MAX232
目 录
1.2国内发展现状及发展动态……………………………….. 2
1.3国外发展现状及发展动态……………………………….. 2
2.1 系统的总体设计方案………………………………….. 4
2.2 湿度传感器的论证与选择………………………………. 4
2.3 温度传感器的论证与选择………………………………. 6
3.1.1 STC89C52主要功能………………………………. 8
3.1.2 STC89C52芯片引脚说明…………………………… 8
3.1.3 STC89C52的时钟振荡器…………………………… 9
3.1.4 STC89C52复位电路……………………………… 10
3.2 系统键盘按键电路设计……………………………….. 10
3.3 显示电路的设计…………………………………….. 12
3.4 报警电路的设计…………………………………….. 13
3.5 湿度检测模块的设计…………………………………. 13
3.6 温度检测模块的设计…………………………………. 16
3.7 烘干设备模块的设计…………………………………. 17
3.8 单片机通信模块设计…………………………………. 19
第4章 系统软件设计……………………………………….. 23
4.1 系统主程序流程设计…………………………………. 23
4.2 水分、温度检测自动控制软件设计………………………. 24
