LoRa Wireless Sensor Network

Deployed a sensor network on a 5-acre property using RFM95W LoRa modules at 868MHz with Raspberry Pi gateway. All six nodes have been running continuously for 14 months.

Range with 2dBi antennas and clear line of sight is easily 500m. Through building walls, metal roof, and vegetation the worst node at 80m achieves 100% packet delivery. Key protocol decisions: each node sends a self-identifying payload with node ID, sequence number, and sensor data — the gateway logs everything to SQLite. Sequence numbers let me detect dropped packets without round-trip acknowledgment.

Battery life: the nodes use an ATmega328P with RFM95W, wake every 5 minutes, transmit in under 200ms, then sleep at sub-10uA. On 3xAA alkaline the nodes have run for over a year and I still haven't replaced a battery. The key is keeping the RFM95W in sleep mode except during the actual transmit window — even a few seconds of idle radio time dominates power budget.