Luxor: A Perpetual Batteryless Sensing Device Targeting Real-world Long-life Applications

The rapid growth of Internet of Things (IoT) technologies has brought new challenges regarding the sustainability and longevity of sensing devices. Most IoT end-nodes rely on chemical batteries to store their energy which limits their lifetime, increases maintenance requirements, and generates significant environmental impact. This work addresses these issues by presenting a batteryless device designed for real-world long-life sensing applications. Our solution operates autonomously through ambient energy harvesting, using an amorphous silicon photovoltaic cell and a high-efficiency energy management circuit with supercapacitor storage. The system architecture is based on a System-on-Chip Bluetooth coupled with an external hardware timer, achieving ultra-low-power consumption and fully deterministic energy consumption per cycle without firmware overhead. The modular design integrates temperature and humidity sensing, Bluetooth Low Energy (BLE) communication, and adaptable antenna configuration. Experimental validation in a typical indoor office environment (200–500lx), with a 30-minute sensing interval, demonstrated reliable and stable performance, achieving transmission success rates above 96.5%. These results confirm the feasibility of sustainable and long-lasting IoT deployments without battery-related maintenance.