IoT Battery-Less System for Plant Health Monitoring

In this work, we introduce an innovative battery-less Internet of Things (IoT) device designed specifically for the purpose of monitoring plant health. This system operates by gathering energy directly from the soil where the plant is rooted, employing a combination of the electrode potential principle and a cutting-edge maximum power point tracking algorithm, optimizing energy harvesting and ensuring that the system operates at peak efficiency. The harvested energy is efficiently stored within a supercapacitor, which subsequently serves as the primary power source for a highly energy-efficient System on a Chip (SoC). This SoC, in turn, is responsible for collecting and transmitting data related to light conditions and soil humidity. The data is transmitted via Bluetooth Low-Energy (BLE) technology, making it accessible for remote monitoring and analysis. Initial results from our research showcase the remarkable feasibility of the proposed system. We have successfully demonstrated its capability to extract energy from the environment, as evidenced by a fully functional prototype that relies solely on energy harvested through this method. A 330 µF capacitor has been charged in less than 3 min for the initial power-on of the whole system and less than 20 s after the initial startup, providing a 3 mA current to a standard LED for about 300 ms.