Design And Implementation Of The Wireless Sensor Network Hardware Platform Based On NRF905

Wireless Sensor Networks (WSN) is a multi-hop and self-organizing network system connected by the wireless communication. It is the core component of the future mobile communication which integrate embedded system, distributed processing, sensors, wireless communication technology, etc. WSN has been used in industrial automation, agriculture, transportation, intelligent monitoring and other areas and has broad prospects for development.Sensor node is the basic hardware platform in wireless sensor networks. It is a micro-embedded system which has signal acquisition, data processing, wireless communication and other functions. At present, there are already varieties of products of sensor nodes. But their prices are still high and not suitable for large-scale layout. Moreover, the sensor node has already integrated protocol stack. So it is not suitable for laboratory studies. Therefore, this article is based on requirements of the actual engineering application, as well as to provide the hardware platform for laboratory studies. A kind of wireless sensor network node and its self-organization communication protocol are designed with the core of the transceiver nRF905 and a MCU of STC12 series.Firstly, based on the deep research of the WSN, the hardware design of sensor node is given, as well as the design requirements of wireless communication protocol.Secondly, each module of the node selection and circuit design has been completed; the underlying software design has been given as well. Then a kind of the wireless self-organizing communication protocols which is based on the DSR routing protocol has been designed, the solutions of key problem of the communication protocol has been given. The flow chart of each process is given in software design of the communication protocol. Then the communication protocol software design is eventually achieved.Finally, some tests have been carried out, including the transmission distance test, self-organization test, route maintenance test and throughput test. The result shows that the network realizes multi-hop transmission and the self-organization. Its communication is stable, reliable and the network throughput has achieved the requirements of wireless sensor network.