The Design And Implementation Of Wireless Sensor Network Node

Wireless Sensor Network(WSN) is a combination of sensor technology, embedded computing technology,distributed information processing and communication technology.It can provide collaboration in real-time monitoring, sensing and acquiring the information of the distributed network within the region or a variety of environmental monitored objects.After processed,the detailed and accourate information is acquired and sent to users who need it.It can be expected that with the rapid development and wide application,Wireless Sensor Network will bring our social life and industries a tremendous impact and promotion.The main work and research results are as follows:(1) It studies the structure of Wireless Sensor Network node and its power consumption.This paper studies the structure of WSN node,and divides it into four modules according to their functions,then analyzes the energy distribution,and focuses on the relationship between the power comsumption and parameters such as modulation.It studies the circuit energy distribution of WSN node.Based on these researches,it proposes a series of solutions to lower the power comsuption.(2) It designs and implements the hardware system of Wireless Sensor Network node.Considering such traits of WSN node as the low power comsumption,small size,complexity of the working environment,this paper propose a design and implementation of the hardware architecture of WSN node,which includes the chip selection and the peripheral circuit,antenna,interface circuit,sensor and power circuit schematic and PCB designs.During the PCB development and research,this paper studies the EMC and SI problems and researches the wire layout and board layer.(3) It designs the system software from Hardware Abstraction Layer.The WSN node uses the Zigbee protocol,which is based on IEEE 802.15.4.This paper analyzes and researches the Physical and MAC layers of the ZigBee protocol,and proposes a design of low layer software system of WSN,which includes programs of interfaces such as USART and SPI,data acquisition and wireless communication of both send and receive.(4) It debuggs the designed node system.The debugging work indicates that the node can receive signal from sensor and then send the acquisition datas to the process unit,and the process unit can exchange datas with the communication unit via SPI,or with upper monitor via USART,and the communication unit can send or receive signals from other nodes.The designed node system can meet the functional requirement of WSN.During the debugging work,some important information is acquired.(5) It tests and analyzes power consumption of the designed node system in different working state.The experiment indicates the feasibility of the low power consumption research in this paper,which can prolong the battery life efficiently and meet the power requirement of WSN.