A battery-less switch for use in 802.15.4 / ZigBee applications

Wireless switches to control light systems are important parts of wireless networks in building automation. For success, it is important to avoid frequent battery replacement, or even better to eliminate them. Although this is possible in some proprietary systems today, at the expense of some features, it is still a challenge for networks such as ZigBee. The main difficulties lie in the power available and the requirements for communication. In this paper, we present the design of a battery-less wireless switch that can be integrated in 802.15.4 / ZigBee systems. We use a standard energy harvesting module for generating power when the switch is activated. The important and required power management aspects implemented in hardware and software are discussed, in the light of the network specifications. After showing the challenges needed to overcome the use of a battery-less switch in wireless systems such as 802.15.4, we present our solutions and the results of some tests