ForestGuard

ForestGuard is a distributed embedded system designed to protect forested areas through continuous, autonomous sensing. Each detection node is built around an STM32WL55JC1 microcontroller paired with an IKS401 sensor shield, integrating a flame sensor, a high-sensitivity microphone, and environmental modules that monitor temperature, humidity, and air quality in real time. The nodes form a wireless mesh network using LoRa on the 868 MHz European band — a protocol chosen specifically for its multi-kilometre range and ultra-low power consumption in areas with no cellular coverage. Locally processed sensor data is aggregated at a remote monitoring station that handles storage, live visualisation, and alarm management.

Deploying electronics reliably in outdoor, uncontrolled forest environments imposed strict constraints on every layer of the design. Power was the hardest constraint: nodes needed to operate indefinitely without maintenance, requiring careful balancing of LoRa duty cycles, sleep/wake firmware scheduling, and solar harvesting logic matched to real-world irradiance conditions. On the sensing side, false positives were a serious risk — a campfire, reflected sunlight, or insect noise could trigger spurious alerts. The firmware implements multi-sensor fusion and adaptive thresholding algorithms that require all relevant channels to agree before escalating to an alarm, keeping the false-positive rate low without introducing unacceptable detection latency. LoRa channel management in a dense node deployment also required careful frequency planning to avoid collisions at the gateway.

Submitted to the 2024–2025 national STMicroelectronics contest. The final prototype demonstrated autonomous, continuous forest monitoring across a distributed node network, with local alarm logic, solar-sustained operation, and real-time telemetry delivered to a remote monitoring station over LoRa 868 MHz.