The Design Of Wireless Temperature Humidity And Illuminance Monitoring System

Temperature, humidity and illumination are three important factors to ensurecrops to grow well, currently in agricultural production, manual control andexperience-based judgement are still used to measure these three basic factors, suchas the temperature and humidity in greenhouse were detected by the instrument tocontrol the environment. In recent years, with the rapid development of wirelesssensor network technology, the WSN will be applied to agricultural productionmonitoring field, it can not only effectively solve the limitations of existing methodsof detection and control, but also has the characteristics with collecting data, massdeployment and improving the monitoring of business efficiency, reducingequipment maintenance costs and increasing economic efficiency and etc.. Thisdissertation design a wireless sensor network monitoring system for agriculturalproduction environment, main contents and results are as follows:Firstly, after analyzing the practical requirements of agricultural productionenvironment parameter measurement, in order to ensure the data transmit correctlyand save energy to extend the lifetime of the network, the overall scheme of wirelesssensor network monitoring system wherein temperature, humidity and illuminationsensors with star structure is designedSecondly, considering the practical need of measurement of temperature,humidity and illumination in agricultural production, the type of the sensors areselected, also design and debug the sensor module, processor module, wirelesscommunication module and power supply module. In consideration of the actualapplication requirements, several wireless sensors is designed to integrate on to thebaseboard to improve the generality of the sensor node.Thirdly, modularity is considered when designing the data link layer, networklayer and application layer etc. The network layer design scheme is proposed tosupport the temperature, humidity and illuminance sensor node to have the ability of information query and configuration. So configuration of sensor type, acquisitioncycle, temperature warning limit and humidity warning limit can be set according tothe different requirements of different crops. The dynamic slot allocation MACprotocol based on TDMA is designed, which give consideration to the energyconsumption and delay of network.Fourthly, related function and performance of the wireless temperature andhumidity and illuminance sensor network monitoring system are tested in laboratory.Testing items include radio frequency performance, the quality of wirelesscommunications, data acquisition reliability, networking function and node packetloss rate. At the same time, the testing results are analyzed in detail and an improvedplan is proposed. Through the long time running test in laboratory, the result showsthis system can run stably and reliably.