The Design Of Wireless Sensor Networks For Hosehold Environmental Monitoring

Research on smart household sensor networks is one of the important issues for the development of sensor network industry. This new industry has been incorporated explicitly in"the Development Plan Outline for Medium and Long Term Science and Technology Development (2006-2020)"and "the National Industry Roadmap by the year 2050".In order to provide a more intellectual and more efficient living system, one of the hot topics for next-generation intelligent building is to connect various information sensing devices, including infrared sensors, radio frequency identification devices (RFID), laser scanners, et al, to the LAN, internet, and mobile communication network via a wired or wireless ad hoc network approach, in which the information for furniture and appliances in our house can be remotely sensed and controlled.After studying the fundamental theory of ZigBee technology and its organization techniques, a design scheme of wireless sensor networks has been proposed for the household environment monitor in this paper, which is based on our present domestic technology.The sensor system consists of terminal nodes, central nodes and a host computer. The distributed sensor networks are made up of wireless ad hoc network terminal nodes, which collect the information of CO2 concentration, temperature and humidity. The communication between central node board and host computer is via RS232 interface. Therefore each node can not only work as wireless network node, but also function separately as a sensor measurement device. A terminal node can also be employed as a routing one, which will connect more sensor nodes and hence expand the scope of wireless transmission. A central node collects the data from each sensor nodes, which will be sent to the host computer for display analysis and further processing. A small ZigBee network has been constructed, in which the detection of environment parameters is realized, and the control function is tested for the terminal nodes as the actuators. Some interface has been left beforehand for further investigation.