Batteryless BLE and Light-based IoT Sensor Nodes for Reliable Environmental Sensing

TL;DR

This paper presents the design and implementation of batteryless, energy-harvesting IoT sensor nodes using BLE and Light-based technologies, achieving reliable environmental sensing without batteries by adaptive energy management.

Contribution

It introduces a novel integrated design of batteryless BLE and Light-based IoT nodes with adaptive duty cycling for continuous, reliable operation powered solely by indoor light energy.

Findings

BLE nodes communicate every 19.3 seconds reliably.

LIoT nodes communicate every 624.6 seconds reliably.

Adaptive duty cycling ensures continuous operation without batteries.

Abstract

The sustainable design of Internet of Things (IoT) networks encompasses considerations related to energy efficiency and autonomy as well as considerations related to reliable communications, ensuring no energy is wasted on undelivered data. Under these considerations, this work proposes the design and implementation of energy-efficient Bluetooth Low Energy (BLE) and Light-based IoT (LIoT) batteryless IoT sensor nodes powered by an indoor light Energy Harvesting Unit (EHU). Our design intends to integrate these nodes into a sensing network to improve its reliability by combining both technologies and taking advantage of their features. The nodes incorporate state-of-the-art components, such as low-power sensors and efficient System-on-Chips (SoCs). Moreover, we design a strategy for adaptive switching between active and sleep cycles as a function of the available energy, allowing the IoT nodes to continuously operate without batteries. Our results show that by adapting the duty cycle of the BLE and LIoT nodes depending on the environment's light intensity, we can ensure a continuous and reliable node operation. In particular, measurements show that our proposed BLE and LIoT node designs are able to communicate with an IoT gateway in a bidirectional way, every 19.3 and 624.6 seconds, respectively, in an energy-autonomous and reliable manner.