Commercial garage door openers are a little different beast than your standard door opener. Standard garage openers have one button, where as the commercial versions normally have 3. The button configuration is a bit confusing as well, so lets go through this setup.
First, lets talk about wiring. The LCE-3 has three buttons, the Open & Close buttons are ‘normally open’ buttons, meaning when you push them, they close the circuit to activate the opener with the requested action. The STOP button however is a ‘normally closed’ button, meaning when you push the button you are disrupting the circuit.
To get this connected to the raspberry pi, I used a 5v 4-channel relay switch. I connected the open and close buttons using wiring going from the normally open position on the relay to the button terminals on the controller. For the STOP button, I cut the wire going to the stop button, and wired the relay normally closed position in line. I connected Channel 1 on the Relay (OPEN) to GPIO 17 (Pin 11), Channel 2 (CLOSE) to GPIO 27 (Pin 13), and Channel 3 (STOP) to GPIO 22 (Pin 15).
I then installed the Blynk Server on my Raspberry Pi, and configured 3 buttons using the GPIO information above. The Blynk app is crazy simple to use, and there are tons of tutorials around so I’m not going to outline that here today.