LoRa-Based Multi-Node Environmental Monitoring of Ponds in the Vicinity of Bhaktapur

Abstract

LoRa (Long Range) radio technology can be used for long-range, low-power environmental monitoring in distributed locations such as ponds. However, its default ALOHA-style channel access causes packet collisions and limits scalability as node count grows. This paper presents the design, implementation, and field evaluation of a Time Division Multiple Access (TDMA) based multi-node LoRa system for monitoring ponds in the vicinity of Bhaktapur, Nepal. Three ESP32-
based sensor nodes (temperature, humidity, and pressure), synchronized via DS3231 real-time clocks (RTCs) and interfaced with SX1278 LoRa transceivers at 433 MHz, transmit data to a central receiver in a star topology within dedicated time slots, entering deep sleep otherwise to conserve energy. The system was field-tested under close and long-range conditions across three Spreading Factor/Coding Rate (SF/CR) configurations, with a Flask dashboard for data visualization. Across three SF/CR configurations, trends in packet loss, RSSI, and SNR are analyzed to identify a reliable, energy efficient setting for a three-node pond monitoring deployment, indicating configuration choices that are promising for further scaling.