Uses a D1 Mini and Arduino code with an HTU21D for ambient sensing and two DS18B20 OneWire sensors for inlet and outlet temperature measurement. The heat-pump mode detection uses temperature difference and its derivative of the inlet and outlet temperatu
Measures the relationship between light intensity and solar panel power output. Panel is 80 x 55 mm rated at 6 V 100 mA. An INA219 measures current, voltage, and power output. A TP4056 controls the charge of a 600 mAh cell. Reports every 5 minutes.