Autonomous Wireless Sensor Node for Building Climate Conditioning Application

The paper reports on the development of an energy optimized wireless sensor node for building climate control application. The presented sensor uses a small photovoltaic module to harvest the energy from indoor light. The average current consumption of the every minute measuring and transmitting node is 2.5μA. Due to its ultra low power consumption the sensor node needs only 100lx of fluorescent light everyday during 8h for its sustainable operation. In dark environment the sensor can work up to 2 months using the energy progressively accumulated in a coin-cell rechargeable battery. Optimization of the system architecture, careful component choice and smart power management were carried out in order to extend sensor life-span beyond 10yrs at nominal operating conditions.