Ultra low energy wireless temperature sensor network implementation

Condition monitoring in buildings is one of the most potential and foreseen applications for wireless sensor networks (WSN). This paper presents the design and full scale prototype implementation of WSN for temperature monitoring. The prototypes are implemented using low power commercial of-the-shelf components including a 2.4 GHz radio, microcontrollers, and a custom TUTWSN communication protocol. A user application provides a graphical data analysis. Measurements indicate 183 muW to 390 muW average node power consumptions, as temperature is measured at 5 s intervals and data is multi-hop routed to a gateway. Predicted lifetime with two AA batteries is up to 4.9 years. In addition, experiments indicate that time accuracy is extremely important in hardware prototypes