A self-powered WSAN for energy efficient heat distribution

The impact of IoT might significantly be increased by autonomous nodes with both sensing and actuating capabilities. This article describes the project of a wireless sensor and actuator network (WSAN) made up of autonomous nodes. Both the sensing and actuating nodes sense and communicate the temperature through the DASH7 coordinator. In addition the actuating node drives a motor to tune a valve controlling a radiator. Connectivity is provided by the above-mentioned low power protocol DASH7 running over a subGHz radio network. Nodes are powered by harvesters. The WSAN is intended to be a nearly unobtrusive component of a smart environment addressable by a gateway with edge-computing capabilities. Monitoring and actuating features are exposed by the network and are available to remote mobile clients. Thus an Internet of Things scenario is implemented with autonomous components, a gateway and a user friendly interface built on a simple Android application. The paper sketches the proposed architecture and is focused on the first node prototypes, their design challenges and preliminary measured performance. Requirements for self-sustainability and trade offs between service responsiveness and availability are discussed.