The Design Of Mine Wireless Communication System For SAW Gas Sensor Based On Zigbee Technique

At present, there are two main ways to monitor concentration of gas in coal mine, and one is the manual inspection by portable gas detector, and the other is located gas detection system. The manual inspection is low efficient, and it cannot get the real-time detection also with the risk increasing. The wired gas detection system need take much time and effort to establish the connection between the sensors and the control center, and so it’s not very easy and convenient. Zigbee wireless communication technology has the characteristics of low power consumption, low cost and high security. Surface acoustic wave(SAW) sensor compared with other type of gas sensor has remarkable sensitivity and stability, and it is also easy to be miniaturized and integrated. In this research, the combination of Zigbee with SAW technology is investigated and applied in the coal mine gas monitoring, and it should be very significant for promoting the coal mine safety technology.The principle of Zigbee wireless technology and SAW technology are discussed in detail in this research, and the hardware and software design of Zigbee node are proposed,and the process of network construction is studied deeply too.In the aspect of hardware circuit, Altium Designer is used to complete the schematic diagram and the development of PCB. CC2530 chip of TI is used as the control chip of the whole system, and the design of the system’s power supply circuit, USB to serial circuit, sound and light alarm circuit, and the RF circuit based on CC2530 etc. have been done in this research. About software development, IAR is used to develop initialization program, node connecting into network program, and serial port driver program. In the process of this research, the Smart RF Packet Sniffer software is used to grab the data packet, the data decoding and analysis.In this paper, the designed nodes of the network communication can not only communicate with the surface acoustic wave system with serial communication, but also communicate wirelessly among nodes. Moreover, the research on the relation between serial communication with the height of nodes is made, and the results show that the transmission efficiency of Zigbee is obviously affected by the surrounding objects.The purpose is achieved in this research, and it’s significant for the application ofSAW sensing combined with Zigbee wireless technology, and it’s also very important for the application of wireless technology in coal mines.