OpenBSD lets one control the GPIO pins on a Raspberry Pi. Controlling a garage door is simple: connect the GPIO output pin to one side of a relay's coil, connect the 5 volt output of the Pi to the other side of the relay's coil, and connect wires from your garage's wall console to the relay's common and "normally closed" ports. Running the program below opens or closes the door. Since the Pi will be connected to the garage wall console, you'll want to enable sshd. I've named my Pi "garage" and my program "og," so I can open the door remotely with
ssh garage /home/sven/bin/og
https://undeadly.org/cgi?action=article;sid=20210527120047#hardware