The Application Research Of Low-Power Sensor Network Nodes In The Environmental Monitoring System

Wireless Sensor Network (Wireless Sensor Networks, in short WSN), is a kind of unmanned systems. It is composed of large number of sensor nodes which are deployed in monitoring region, it is forming a multi-hop and self-organized network system through wireless communication, the information of monitored area is cooperatively sensed, collected and processed. WSN can be applied in medical treatment, environment monitoring, and minitary area.ZigBee network is designed to execute monitoring behavior, it is a unified technical standard of short distance, low rate wireless communication technology, with IEEE802.15.4protocol standards together defining a complete applicable to the wireless sensor network protocol structure. The protocol structure is divided into five layers: physical layer, MAC layer, NWK layer, security layer, application layer, the user can according to their application needs to make the corresponding revision, to complete the development and utilization of it.As everyone knows, the entire sensor network environment monitoring system is based on the sensor node, the low power consumption, low cost, small size and other characteristics which has been widely used, but the node environment often determines the energy problem must being the key of the sustainable network operation. Therefore, this paper based on the perspective of low energy consumption, and using of TI launched the commercial Z-Stack protocol stack, in order to the wireless sensor network environment monitoring system for real time research and application, and the monitoring data processing and analysis, to obtain the real-time environmental monitoring.At the beginning,this subject started from the research background and significance, the structural characteristics and application of the wireless sensor networks is introduced, put forward to realize low power network design problems and challenges and takes the ZigBee/IEEE802.15.4protocol in detail, this part is to build the structural basis of environmental monitoring system. Using the official TI to provide the latest technical reference to IEEE802.15.4CC2530as a network of sensor nodes in the main control chip, and on this basis, from the respect of power management module, the node of the upper data acquisition and processing module and the lower floor control module of the node low power design;on the other hand from dormant circuit, network topology structure in order to realize the ZigBee alliance specifications of the best Z-stack protocol stack software platform to build the environmental monitoring system in low power consumption data acquisition.Finally in the subject of the node and system on research foundation, builds the application to environmental monitoring system, the whole system is composed of a coordinator node and a terminal temperature acquisition node. And the monitoring system and system used in the network node, communication and performance aspects are tested. The test results show, sensor nodes can properly complete network, design of the solar battery group for power is supply to the demand of power supply, system can get the temperature of the environment, and result accords with the external environment of the actual temperature values, node communication distance can reach200meters, and the transmission process is stable, delay relatively is small and the whole system design is more successful.