How it works
The probe wakes on a timer, powers its sensing circuit, reads soil moisture at three depths — shallow (≈1"), mid / root zone (≈3.5"), and deep (≈6") — then transmits one small, cryptographically signed LoRa packet and goes back to sleep. Because it sleeps most of the time and the solar panel recharges the battery faster than the probe drains it, gophr is energy-positive: it runs indefinitely with no battery changes and no charging visits.
Key capabilities
- Capacitive sensing: an on-board oscillator excites each soil pad and an envelope detector converts the coupling to a voltage — each pad calibrated dry-to-wet, reported as a percentage
- Sensor roles configurable in software: by default mid drives watering decisions, shallow detects rain, deep guards against over-watering
- Every reading signed (HMAC-SHA256) with a private per-device key handed over during Bluetooth provisioning
- Range extendable across any property via pidgn extenders
- Magnetic reed kill-switch ships it powered off
Specifications
| Processor / radio | ESP32-C3 + SX1262 LoRa @ 915 MHz, SF10 / 125 kHz — long range at low power |
| Sensors | 3× capacitive moisture (shallow / mid / deep); battery + solar telemetry |
| Power | Li-ion + solar (MPPT charger); deep-sleep duty cycle |
| Range | Long-range LoRa, extendable via pidgn extenders |
| Updates | Three paths — Bluetooth, WiFi, or over-the-air via LoRa |
magpi — $200
pidgn — $200
keepr — $300
kukoo — $100