How it works
frogg is an always-on air temperature and humidity sensor that computes Vapor Pressure Deficit — the gap between how much water vapor the air could hold and how much it does: the drying force plants feel. It is USB-powered with a vented enclosure and streams every reading to the cloud, where VPD is computed with the Tetens equation and dew point with the Magnus formula. User-configurable calibration offsets are applied before those equations, so every derived value recomputes from corrected inputs.
Key capabilities
- Greenhouse mode: VPD drives decisions in place of outdoor weather — pick a crop profile or a custom VPD target (default 1.0 kPa)
- Hard safety rails: frost cutoff at 5 °C and heat-stress guard at 35 °C
- Multiple frogg sensors aggregate worst-case by default — the plant in the harshest corner sets the pace
- Always-on by design: sleep is permanently disabled because VPD control needs a continuous signal
Specifications
| Processor | ESP32-C3 (WiFi + Bluetooth) |
| Measures | Air temperature, relative humidity, barometric pressure (+ optional secondary temperature probe); VPD + dew point computed in the cloud |
| Duty cycle | Continuous (always-on) — required for VPD control |
| Power | USB |
| Setup / Updates | Bluetooth provisioning · WiFi OTA |
keepr — $300
gophr — $200