PLEASE: an Open-Source Emulation Platform for Development of Sustainable and Battery-Less Sensor Systems

Driven by the increasing demand for data, connectivity and automation, the amount of Internet of Things (IoT) devices continues to expand across consumer electronics and industrial applications. Integrating energy harvesting (EH) technologies as a battery-free alternative requires a controlled setting to emulate realistic EH systems. Yet, current tools are often not sufficiently accurate to model all hardware and software components of an EH system. Moreover, it is hard to mimic realistic energy availability scenarios, which are crucial for the design and optimization of EH systems. Therefore, a novel emulation platform is introduced that facilitates the development, testing, and optimization of complete and realistic EH systems. This emulator device replicates the behavior of the entire EH system. It consists of a Raspberry Pi 5 with a custom developed add-on hardware hat and dedicated software. This add-on hardware hat provides a stable output voltage between 1.2 and 3.6 V to the IoT device under test and contains a current measurement circuit with an accuracy of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.6~\mu $ </tex-math></inline-formula> A. The software includes novel and accurate digital-twin models of the energy harvester, the storage element, and the power management unit, enabling the emulation of various EH scenarios. Two application scenarios are demonstrated, a wireless bluetooth low energy (BLE) heart rate sensor optimized for ambient light EH and a compact wireless BLE temperature sensor optimized for radio-frequency EH. The proposed emulation platform enables rapid EH design evaluation under varying energy conditions, streamlining development and validating system reliability. This could be an important step toward establishing EH as a sustainable and widely adopted alternative to conventional battery-powered systems.