Battery-Less Sensor Node Design with Solar Panels and LoRa for Wireless Sensor Networks

Abstract

A wireless sensor network (WSN) is a network of sensors that detect physical changes and convert them into analog or digital signals. These sensors communicate with each other to monitor and collect data from a specific area. Applications of WSNs range from environmental monitoring to agriculture, industrial automation, etc. The current WSN nodes are powered by rechargeable batteries and designed for short distances. The problems faced with current WSNs are short-distance communication, battery replacement in large, deployed networks, and rechargeable batteries that take longer time periods to recharge. The term “battery-less” refers to devices that operate without traditional batteries or external power sources. In this design, solar energy is used as a sustainable energy source, and supercapacitors are used to store the solar energy. Supercapacitors have a greater number of charging-discharging cycles than batteries, which can operate in a wide temperature range. They are also more environmentally friendly than typical batteries. LoRa is the technology used for long-range communication, which operates in Industrial, Scientific, and Medical (ISM) radio bands, which is the most cost-effective technology that provides wide coverage with low power consumption. For power management, lowpower approach and sleep mode are used to make the sensor node work efficiently with the stored power in the supercapacitors. The whole system design was optimized, taking scalability, performance, and cost-effectiveness into account.