Vegtrug sensor sends Bluetooth BLE beacons to an ESP32 running ESPHome, powered by a power bank that outputs USB-C (other types will shut off automatically). ESPHome runs in Home Assistant and stores data into InfluxDB for graphing with Grafana.

The sensors are best used for relative moisture at a single point rather than comparing moisture between locations. I look for the spike after watering, and then estimate the percentage for field capacity after it drains for a few hours.