Low-power LoRa wind sensor

• Main Author: Ho, Jervis Xing Xian
• Other Authors: Mo Li
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Computer science and engineering::Computer systems organization::Computer-communication networks; Engineering::Computer science and engineering::Hardware::Input/output and data communications
• Online Access: https://hdl.handle.net/10356/144622
• Institution: Nanyang Technological University

LoRa (Long Range) is a type of LPWAN protocol that stands out for being resilient to Doppler effect and its high channel capacity. This is attributed to its use of a variation of the Chirp Spread Spectrum (CSS) technology, of which LoRa PHY’s encoding and modulation process allows it to negate a high degree of interference and the time shift caused by the Doppler effect. All these benefits are achieved at the cost of low bandwidth/data rate, but do not hinder the functionality of the technology. LoRa devices are mostly sensors such as temperature sensors and anti-burglary detectors, all of which do not require large bandwidths to operate but instead prioritize operational reliability. As sensors are expected to transmit data periodically, active and sleep cycles are implemented to help reduce its power consumption. Sensors capitalize on reducing power used during sleep cycles, then transition to active cycles only when data needed to be transmitted. However, the long times that sensors are deployed causes the sleep cycle to take up a significant amount energy. This project focuses on drastically reducing that energy used during the sleep cycles by implementing a trigger-based wind sensor that sends an interrupt that turns the Micro Controller Unit (MCU) active. Results from this research would give LoRa device manufacturers an insight on how to further reduce their device’s energy consumption.