Air Conditioner Simulation at 20C
Mikroe HVAC Click Board with SPS30 and SCD4x
Using an ESP8266 ESP-01 module and an Arduino Pro Mini 3.3V I wirelessly update all outputs from my thermostat to here for data analysis and because it's cool. This requires a voltage divided rectifier since thermostats run at least 24 VAC RMS.
Nest Thermostat Data Logging
ESP8266 with a ds18b20 temperature sensor mounted in the HVAC plenum right above the air handler.