The Node Design Of Environment Monitoring Wireless Sensor Network Based On ZigBee

With the modern high-tech progress, people's living standard has been greatly improved. At the same time, the demands on the environment are more and more strict and the society has been paying attention to environmental issues. At present, developing a low-cost remote monitoring system to suit China's national conditions is an important direction in the development of environmental monitoring. How to obtain the environmental parameters is an important part in the environmental monitoring system. Only by obtaining the environment parameters,the analysis and the decision-making work can be carried on. Wireless sensor network (WSN) could monitor real-time, detect and gather cooperatively all kinds of information of environment or monitored objects through various integrated sensors. And then it transmits the information to users. WSN can be a rapidly deployed, automatic, low power consumption and low cost system. Therefore, the WSN is very suitable for the environmental monitoring system.Based on the ZigBee protocol, a WSN sensor node for the environmental monitoring system is designed. This node uses the ultra low power MCU MSP430 and CC2420 RF chip. The Z-Stack which is compatible with the ZigBee 2006 standard fully is transplanted into this node and the monitoring code is running on the stack. So, the node can gather the temperature, humidity and atmosphere pressure of the surrounding environment, calibrate automatically and transmit the data to the neighbour node through the wireless sensor network. This node has the features of small size, low power consumption and high compatibility. This node can construct the ZigBee WSN with a different hardware platform with the full compatibility of the application layer. These features could not only facilitate the development of the code, but also make the network more flexible and optimized.This paper mainly introduces the hardware and software design of the wireless sensor network node for environmental monitoring. The hardware includes the design of the data acquisition module, the data processing module and wireless communication module including on-board antenna, balun circuit and PCB design of the high-frequency circuit. The software includes the design of the measurement procedure, wireless communication procedure of CC2420, and the transplanting and development of Z-Stack for the application of environmental monitoring system. Finally, an experiment for the network communication is made. The designed node and the CC2430 nodes are put together and made to communicate in the ZigBee network. The packet sniffer is used to monitor the communication information. The experiment proves that the mixed ZigBee Network is entirely feasible and the communication is stable and good.