The garage door wall switch uses a dry contact to toggle the door opener. The ESP Opener parallels those contacts with a dry set of contacts from a small relay. The ESP has a statIc IP assignment in my household router so I always know how to reach it. The specific ESP8266 module I'm using is the ESP201. Some ESP modules won't work with a relay, when they boot up certain outputs are pulsed. This gets it stuck in a boot loop. This could be avoided by using a transistor but if your ESP were to restart in the middle of the night your door could open up.
Enjoy this project?