ESP8266 with a ds18b20 temperature sensor mounted in the HVAC plenum right above the air handler.
Test Water Heater Monitor. Adafruit HUZZAH ESP8266 module, FS300A G3/4 flow sensor, two DS18B20 thermometers, current, and voltage measurement using ADC. Monitors hot and cold water temperatures, hot water usage, current, voltage, and energy usage by th
Propane tank level as measured by a ratiometric hall effect sensor mounted over the tank's analog dial gage. Uses an Arduino Mini Pro and an ESP8266 Wi-Fi module, powered by a 3.2V LiFePo4 battery and solar cell.