Temperature And Humidity Measurement System Design And Implementation Of Greenhouse Based On Singlechip

Current a lot of greenhouse temperature and humidity detection systems are used bythe analog temperature sensors, analog switch and A/D converter and other componentsof the transmission system. The acquisition system of temperature and humidity ingreenhouse the layout of the large number of thermometric cable, can be on-sitemeasurement signals of a sensor is transmitted to the monitoring end, not only themounting and dismounting troublesome, but the cost is also high. The line transfer oranalog signal, thus vulnerable to interference and loss, and measurement errors arerelatively large, is not conducive to the user according to the temperature changes in atimely decision. Therefore, the development of a real time, high precision, which cansynthesize the multipoint temperature and humidity information monitoring system isvery necessary.The system hardware is composed of two parts, divided into upper and lowermachine. PC is the entire system monitoring center, by a microcomputer, and the lowerposition machine connected to RS-485, temperature and the indoor temperature andhumidity monitoring data processing and analysis of the simple. The lower positionmachine core component is the AT89S51microcontroller and temperature and humiditysensor complex SHT11, which completed the parameters of temperature and humidityacquisition, preprocessing, display, alarm and other tasks, and with the host computercommunication among.System software also consists of two parts. Upper part of using VisualBasic6.0development, is composed of four parts are respectively the data real-time monitoringpart, historical data report part, temperature and humidity change curves procedures, helpfiles, each part to achieve their respective function, and independent of each other. Thelower position machine software using C language and AT89S51singlechip assemblylanguage mixed programming, mainly consists of6parts, respectively is the main part ofthe program, receiving the service program, sending service part of the program, dataacquisition part of the program, an acousto-optic alarm procedures, data processingdisplay part. And on the SHT11and SCM connecting portion of the Proteus simulation. The whole system has many features, easy to use, high efficiency, easy to expand, stronguniversality, strong applicability, realization of the greenhouse environment in manyaspects factors control.This system only completed the temperature and humidity testing, and not thetemperature and humidity control system design, but leave the corresponding interface,can extend the control module, such as a peripherally extending and dehumidifiers, airconditioning and other equipment, can be realized on the temperature and humiditymeasurement and control functions. Therefore, the system has a good applicationprospect.