Study On The Node Of The Wireless Sensor Network For Forest Information Monitoring

The accurate information monitoring through the wireless sensor network in forest is now an important research in forestry information technology, such as forest fire monitoring, tree growth monitoring, environment monitoring. The wireless sensor network for forest information monitoring is generally based on the ZigBee cluster-tree topology. The information data for the forest monitoring is collected together to the network coordinator in the way of wireless jump transmission, and finally sent out through the Internet or GPRS transmission for remote monitoring. In this paper, study work is carried out on the wireless sensor network node for forest information monitoring and the nodes have been developed for the practical needs, also communication between two nodes is accomplished. AT86RF230 is the Atmel's 2.4GHz radio frequency device of high-performance compatible with IEEE 802.15.4/ZigBee, and only very few external devices with the microcontroller can form a wireless communication system. The node hardware circuit design, PCB making and a number of anti-interference measures taken in the high-frequency mixed circuits is described in detail in the paper. The platform of the system software development is based on AVRSTUDIO and ICCAVR, and program modules have been completed in C language based on the levels of protocol. The idea of programming is given, also the flow charts of data sending and receiving based on the hardware platform.Something have been fully taken into account in the node hardware design such as low power consumption, low cost, small size, etc. The low-power and cost-effective components and PCB antenna are applied to reducing cost. Turning off unused internal modules and forcing main chip into sleep state in leisure to reduce power consumption. Digital and analog power isolation design and low dropout voltage regulators and capacitor combination filter could give the components stable and good working voltage. PCB is divided into RF area, simulation area, the digital area to reduce mutual interference. Multi-point grounding techniques combined with large areas of paving can enhance anti-interference ability. RF chip's bottom ground. is crucial to discharging heat prolonging the life.Tested by experiments, the node can achieve data acquisition and remote control display. With AA batteries, the communication distance of point to point is about 100 meters in open zone and 70 meters in plantation. The node is with lower power consumption and higher cost performance. It can be applied to real-time environmental information monitoring network in forest.