Build a Smart Thermostat with ESP32, Home Assistant, and Relays

Ever wanted to ditch your clunky old thermostat for a DIY smart version that integrates seamlessly with Home Assistant? I did—and after a few weekends of tinkering (and a couple of fried relays), I built a reliable ESP32-based smart thermostat. Here’s how you can too. Why Build a DIY Smart Thermostat? Commercial smart thermostats are great, but they often come with limitations: proprietary ecosystems, cloud dependencies, or lack of customization. With an ESP32, a relay, and a temperature sensor, you can build a thermostat that’s: