Based On The Development And Implementation Of The NRF905 Wireless RF Data Acquisition System

Data acquisition is an import branch of information technology and is the foundation of modern measurement technology together with sensor, signal processing and computer technology. Based on a comprehensive review of application actuality of data acquisition system and short- range wireless communication, a wireless data acquisition system was design and realized based on the nRF905 and MSP430 aiming at solving the limitations of wired data acquisition means such as poor mobile performance and the laying of cable is restricted by the environment. The main research content and results in the paper are as follows:(1) According to the needs of application, an overall planning on the system was carried out; the structures of slave station and base station were also designed. The main devices of the system were chosen carefully on the consideration of low power consumption and high anti-interference performance.(2) The designing and debugging on hardware circuit of data acquisition slave station and base station were accomplished. The slave station nodes designed in this paper have 8 input channels for sensor signals, and the highest data acquisition rate can reach 200 Ksps with the solution of 12 bits. The slave station nodes are powered by batteries and the data gathered by them is send to the base station by the means of wireless communication, then the data is sent to the CAN bus by the base station through the CAN interface.(3) The development and debugging on the application software for the wireless data acquisition system was accomplished. The codes for data acquisition and filtering and the driving procedures for wireless module and CAN interface were designed. The codes for the wireless network were also accomplished in the paper.(4) According to the requirements of one base station communicates with several slave stations, a tiny wireless communication network was designed. The design of topology structure of the network, the means of media access, the control strategy for errors and the structure of data frame were carried on. According to the need of the system running at a low power consumption for a long time, a wake up-sleep alternate mechanism was designed which reduced the power consumption greatly. Aiming at avoiding the effect of field interference, the work mechanism based on hopping communication was designed and the external interference was resisted effectively.(5) A test on the system was carried out and the results manifested that the wireless data acquisition system designed in this paper have many merits such as a small size, low power consumption, reliable and steady data transmission and high resist interference performance. The system can serve well in wireless data acquisition and other short-range wireless data transmission areas.