The Research Of Environmental Monitoring System Based On Wireless Sensor Network

Wireless sensor network is a collection of microelectronics, embedded system, wirelesscommunication, distributed information processing and other advanced science and technology.It monitors, gathers and processes the information about the monitored objects within thenetwork coverage in real-time, and transmits the information to the control center wirelessly.Environmental monitoring is one of the important areas of wireless sensor network, andcurrently has a large number of research results both home and abroad. This paper suggests adesign proposal of environmental monitoring system based on wireless sensor network afterdescribing the status and trends about WSN and environmental monitoring system.First of all, the background and research significance of the subject are described in thepaper. There also have a more comprehensive exposition about wireless sensor networks andembedded systems which are two key technologies involved the subject. Secondly, aftercollecting the related material and defining the basic function of system we work out a generalscheme of the system, and the design of sensor nodes, embedded gateway and the monitoringcentre. Thirdly, the paper emphatically elaborated the design process of the sensor node,embedded gateway and monitoring center. The sensor node is composed of the sensing unit,processing unit, wireless transceiver unit and power supply unit. ATMega16L is the control coreof the sensor node which configured SO2, NO2, O3and other sensors to realize the function ofdata acquisition and wireless communication by programming. Embedded gateway placesS3C2440A microprocessor based on ARM920T architecture as its core, and configures theexternal interface circuit. According to the development process of the embedded system:transplant Linux operating system kernel, root file system, writing drivers and upper applications,embedded gateway realizes the function of the environment data collection, collecting the sensordata in WSN, uploading the data to monitoring center, and converting ZigBee agreement toTCP/IP protocol. Monitoring center storage the data to Access database for analyzing, theenvironment quality rating can be displayed by the man-machine interface based on VC. Forth,we test the performance of the system. The results show that the environmental data collected bysensor nodes is highly accuracy and reliability, the embedded gateway can self-organizing sensornetworks, and have the capacity of redundancy for terminal nodes’ joining and leaving. Finally,the problems encountered in the design process and system defects are summarized and therecommendations to further research are also done.