M.Sc. Tezi Görüntüleme
Last two decades have been the time of very important progresses exhibited on digital radio communications. The developments on high frequency semiconductor device and the required smaller sizes for antennas at high frequencies have been effective on these developments. On the other hand the improvements on battery technology and efficiencies on high frequency power amplifiers were other contributors to digital radio systems.Latest developments on this area, the use of digital radio for sensor networks and expanding its network topologies, are just a reformation of currently advanced wireless local area networks (WLAN) for a low cost, smaller size and lower power consumption solution. This reformation has led to establish new standards such as IEEE 802.15.4 (ZigBee).
In this work a measurement probe, which would be portable, battery powered and accessible by a wireless link, is proposed. There are two main reasons for this motivation. First, battery powered measurements are more accurate, since the mains power effects the systems noise profile, and secondly there is a significant interest on the transmission of the measured data to a system in order to draw and present in more complicated systems, i.e. a PC, other than a single line display, or store in a greater size memory. Therefore, the trends on the wireless sensor networks and their components were studied priory to implementation. In the end, the IEEE 802.15.4 (ZigBee) standards have been found more appropriate solution for the proposed study in order to work on a technology valid universally, since there are two major organizations, IEEE and ZigBee Alliance, supporting the standards.In the implementation, the analog signal is sampled by the analog digital converter (ADC) embedded in the processor (MSP430Fxx) and transmitted by a ZigBee transceiver to another ZigBee device which has another MSP430Fxx processor with an attached universal serial bus (USB) port. A PC collects the measured data via USB port draws and stores. The study has been continued to obtain the main limitations and measure the error performance of the designed link. This study would be helpful to researchers and engineers working on wireless sensor networks and similar technologies in terms of understanding limitations as well as its implementation aspects.
Keywords: Wireless Sensor Network, Low Power RF, ZigBee (IEEE 802.15.4), Wireless