A Long-Range Low-Power Modular Platform for Plant Health Monitoring in Climate-Smart Agriculture Scenarios

This paper presents a modular, low-power IoT platform for in-vivo plant monitoring, designed to operate autonomously for years using a single AA lithium battery. The system features a custom dual-board architecture: the Core board, responsible for processing and communication, and the Sensing board, which integrates detection of plant stem electrical signals, soil matric potential, and environmental parameters. The stem sensing subsystem is based on a dual-frequency analog front-end that also employs a digitally programmable relaxation oscillator. This design allows the system to adapt to different plant species and hydration conditions while maintaining low complexity and minimal power consumption. Experimental evaluation demonstrates that a complete sensing and communication cycle is completed in less than 5 seconds, with an estimated lifetime between 5.04 and 10.72 years assuming one data sample every 15 minutes. Preliminary tests conducted in a climatic chamber show the platform's ability to detect plant bio-activity in response to changes in air temperature and light intensity, while also ensuring stable signal acquisition.