Canopy: Sensor nodes that keep my mom's plants alive when we travel

Started because my mom's tomato plants kept dying every time we went on vacation. The first version used WiFi and the batteries died in six hours, so I switched to LoRa which brought it down to a wake-transmit-sleep cycle that lasts about two weeks on a 18650. The nodes are wired up on perfboard - messy but it works. The tricky part was waterproofing the soil moisture probes; I went through three sealant approaches before settling on heat shrink over the connectors. The dashboard is a simple SvelteKit page that polls the MQTT broker and shows charts.

• › 3 sensor nodes running ~2 weeks on 18650 batteries
• › LoRa radio with deep-sleep between 5-minute readings
• › MQTT broker on Raspberry Pi with SvelteKit dashboard

• › Waterproofing took longer than the firmware