Turning a Dumb AC Unit Smart (Without Losing My Security Deposit)
9 hours ago
- The author automated a rental apartment's analog AC unit using a stepper motor, ESP32, and MQTT integration with Home Assistant.
- Two options were considered: controlling the mode dial (stiff, requires high torque) or the temperature dial (loose, low torque); the author chose the latter for simplicity.
- The V0 prototype used leftover parts and a binder clip/cardboard mounting, while V1 improved with adjustable L-brackets and nuts/bolts.
- The stepper motor is controlled via MQTT, exposed in Home Assistant as a 'cover' entity, and combined with a temperature sensor to create a generic thermostat.
- The solution cost ~$15 in parts, works about 80% reliably due to mounting sag, but still reduces manual adjustments and electricity costs.