Research Of Wireless Sensor Network Based On ZigBee

As a new technology to acquire and handle information, wireless sensor network, which is integration of sensor technology, embedded computing technology, distributed information technology and communication technology, has a very broad application prospects. Consisted of wireless sensor network nodes, wireless sensor network is able to monitor, sense and acquire various information of the environment and objects monitored in real-time. After processed, the information is transmitted to the information users.Based on IEEE802.15.4 standard, ZigBee protocol is a kind of wireless communication standard which is specifically designed for remote wireless monitoring applications. The emergence of the ZigBee technology, filling the gap of the wireless communication market of low-speed, low power consumption and low-speed, provides a guaranty for the development of the Wireless Sensor Networks.In this study, an embeded Wireless Sensor Networks based on ZigBee is designed to collect and transmit information. The main work and research are as follows:1. The communication protocol of ZigBee is studied. Physical layer, MAC layer, network layer and application layer, which belong to the protocol of ZigBee, are analyzed. The topology, application and nodes features of ZigBee network are elaborated.2. The hardware system of wireless sensor network node is designed. Considering the wireless sensor node's characters of low-cost, low-power, low-speed and small-size, LPC2138 microcontrollers and CC2420 RF chip are chosen to achieve the design of wireless sensor node. Chip selection, RF model, sensor model, SPI communication interface and peripheral circuit are introduced.3. The C programme based on ARM7 is compiled. The protocol of ZigBee based on MSSTATE LRWPAN is analyzed and successfully applied in operating system based on ARM7. The network is set up and nodes can be linked with the net by using the protocol.4. The designed system is debugged. The procedures indcludes: firstly, the signals are received by the nodes, then the acquisition data is sent to the LPC2138 process module, finally the CC2420 communication module is used to achieve sending and accepting data via SPI. The experiment results show that the system can meet the requirements of wireless sensor network.