Primary Research Of Wireless Sensor Node In Coral Mine Security Monitoring Base On ZigBee Technology

Nowadays, a rapid development is made by the information technology, and a huge change of people's life has been brought by the information network. The progress of the micro-electronics technology, computer technology and wireless communications makes fast development of sensor, which has low-wastage and multi-function, and the small sensor node has various functions such as collecting information, processing data and wireless communications, etc. ZigBee protocol is constituted of IEEE802.15.4's PHY layer and MAC layer, ZigBee network layer and application support layer. Its outstanding characteristic is that the system support low cost operation, easy realization of the dependable data, short-distance operation, the very low power consumption and the different layer's safety, etc. Their frequency segments are .4GHz and 868/915MHz. Adopt ZigBee to build a huge Wireless Sensor Network,which is applied to coal mine monitoring system,collect all information of mine via all kinds of Wireless Sensors,moreover, is disposed by embedded system .tansfer information to terminator,can make up defect of wire device,have merits such as cheapness,convienience,reliability,correction essily and so on.So adopt ZigBee to Wireless Sensor Network is a feasible method to settle coal mine monitoring actural time and on every side.Wireless sensor network (WSN) is made up of a great deal of low-cost subminiature sensor nodes, which are set in the monitoring area. It can make a many-jumps network by the wireless communications by itself. The purpose is apperceiving, collecting and processing the objects which are in the network area, and sending the information, to the observer. The mature in technique and plenty of potential application need brings more and more concern. Wireless sensor network is becoming the domestic and international research hotspot.The academe, industrial departments and martial departments pay sufficient attention to WSN because of the huge value in application of WSN. A number of corporations will take up with the application of WSN in various fields such as preventive medical, monitoring environment, putting out forest fire, researching benthonic boards, exploring planet, etc. Many academies and scientific research organizations have joined this research. This thesis begins with researching development status of mine industry monitoring system, brings forward the settled project based on ZigBee,discusses ZigBee standard and Microchip protocol structure. According to the exploitation principle for embedded system, I have designed a hardware platform which could be used to develop with ZigBee , developed a series of sensor terminal nodes and coded software that accompanies with it. It uses the PIC18LF4620 as the MCU, uses the CC2420 chip as the RF module and then establishes a platform for WSN. The MCU communicate with the RF module by the SPI interface. On the system software design aspect, I use current protocol,API function and source code to code a SPI interface software,data transmit program and system monitoring software.There are seven chapters in this paper, organized as follows:The first chapter introduces the development status of mine industry monitoring system, brings forward the settled project based on ZigBee ,application and actuality of the WSN base on ZigBee.The second chapter introduces ZigBee protocol and 802.15.4 standard, I compare it with other wireless technologies and introduce the network configuration, network conjunction and data transfer mechanism of the ZigBee protocol and Microchip protocol.The third chapter introduces the whole design scheme of Mine Security Monitoring System. And then I analyse the key technology and difficulty development..The fourth chapter expounds the development of the hardware, gives the process of implementation and principle development of the hardware system, develops a series of nodes such as temperature sensor,flesh influence sensor and gas thickness sensor,moreover realizes the alarm problem of the gas thickness sensor node, introduces principle development and design idea of the embedded ZigBee protocol application.The fifth chapter mainly expounds the development of the demo software.This demo software based on LabWindows/CVI and VC realizes mine long-distance monitoring.The sixth chapter gives the result of demo, validate the feasibilith of the system.The seventh chapter concludes all this paper, briefs the job have done , the innovation points and deficiency, and puts up some questions which should be researched continuously in the future.