Study On Construction And Application Of Communication Interfaces In Distributed Wireless Sensor Network

With the development of Wireless Personal Area Network (WPAN), the application area of distributed wireless sensor network has been becoming wider and wider in industrial measurement and control. In order to meet the demand of inserting more sensor nodes into the distributed wireless sensor network conveniently, the construction of the communication interface has became a research hotspot.According to the practical needs, a study on construction and application of communication interface in distributed wireless sensor network is put forward. A universal communication interface is designed in this paper. According to the characteristics of DWSN, through contrastive analysis, a network scheme based on the technology of Radio Frequency (RF) is presented. In order to realize the universality, wireless sensor networks technology, interface technology and embedded real-time system technology are combined together. A/D conversion interface, RS232 serial interface, RS485 serial interface and embedded USB host/slave interface are integrated into an embedded structure module. A communication interface is constructed, which from four types of wired transmission to wireless transmission.The hardware circuit of the communication interface is designed by using four sub-modules of the data processing, the wire interface, the wireless communication and the power supply. Four wired interfaces and the wireless communication modules are completed based on C8051F020, ADM3202, MAX3430, SL811HS and nRF905. Choosing Modbus protocol to convenient for system expanding on the function of distributed wireless sensor network. Its anti-interference self-adaptive hopping- frequency technique is introduced in detail. The applied software of AD Conversion, RS232, RS485, USB Host and wireless transmission is programmed. And the working-flow design of host computer, base stations and nodes is completed. Considering the emerging interface technology USB, this paper mainly discusses the problems of how to develop USB interface circuit according to USB bus protocol and how to design driver program of USB interface. It is a innovative point of this paper that combining the techniques of wireless automatic connection and wired"plug and play"USB interface to build-up USB-RF interface and implement the wireless data transmission of USB interface equipment. Data exchanging between host and the base station is implemented through serial port. The host PC disposes with data and takes charge of the whole DWSN by the application software, which is developed by LabVIEW. Four types of classical experiments have been done from several different aspects. System testing and the result of experiments show that, the communication interface provides a simple and reliable method for building the distributed wireless sensor network.