Development Of Data Transmission System Based On ZIGBEE Technology

The data transmission system based on ZigBee technology is one of the important components of the seismograph, and has the advantages of low cost, low power consumption, expansibility and good compatibility. The wireless data transmission system can realize the real-time transmission andhigh precision positioning of the seismograph, andthe working status of each seismic station can be grasped in real time.A real-time data transmission system is developed using hardware including GPS module based on difference protocol RTCM and ZigBee module of ad hoc network.According to the ZigBee module function, the data transmission system is divided into the main node and the child node. The main node consists of power supply circuit, charging circuit, GPS circuit, ZigBee transmission circuit and serial port to network circuit. The child nodes are composed of power supply circuit,charging circuit, GPS circuit, ZigBee transmission circuit, control circuit and acquisition circuit. They are powered by lithium batteries. The boost and voltage regulator circuit are used to provide power to various chips on the main node and the sub-nodes. Charging circuit contains a lithium battery charge management chip,with input overcurrent protection, battery temperature monitoring and battery reverse protection and other functions. The control circuit is mainly responsible for controlling the power supply of each module, seismic data collection, transmission and storage.This paper proposes a data transmission system based on ZigBee technology,which combines the low-rate wireless personal local area network based on IEEE 802.15.4 protocol stack with carrier phase difference positioning technology. When the sub-nodes and the main node are successfully connected, the plurality of rovers use the RTCM protocol to receive the error correction number from the base station receiver through the wireless data communication link to realize the decimeter positioning accuracy, and through the wireless personal area network, the vibration data collected by multiple sub-nodes are transmitted to the main node on a time-sharing basis. The data of the main node is transmitted to the PC host computer through the wireless bridge.Through the transmission system test, the data transmission system in the long-term data transmission test has high reliability, high precision and high stability.