Long-Range Bluetooth Low Energy Devices for Smart Greenhouse Irrigation Automation

Facing increasing pressure on agricultural productivity and sustainability, this paper explores the feasibility of replacing hardwired connections in massive deployments of sensor nodes for irrigation automation using Bluetooth Low Energy (BLE) over medium to long ranges. Compared to other radio solutions (Wi-Fi, GSM, ZigBee), BLE minimizes power consumption to meet the requirements of battery-coin-powered devices, while offering the possibility to coexist in the access point with other radio interfaces for very long-range communication (typically, LoRaWAN). Although BLE is traditionally applied to short-range connections, its recent enhancements, including extended advertising and forward error correction, are briefly presented and utilized to fine-tune a proof-of-concept implementation for an over-extended range. Tests conducted in real environments demonstrate successful broadcasting at distances up to 440 m.