Garage Door Opener Help

[BrianG]

Small update on this project:

Every time I want to go into the garage, I have to unlock the walk-in entry door. Not a big deal I guess, but I'm lazy, so I thought I'd put another transmitter in the house and just hit it before I go outside. However, the garage opener kit came with only one transmitter for the car. When I went to the place where it was purchased, I found that extra transmitters are close to $50 each. These transmitters are simple enough I could probably build my own and for a lot less than $50, but I'm lazy, so I decided to do things a bit differently.

I picked up a car keyless entry system from ebay for $15 shipped. It was from China and ultra cheap, so it's probably a clone of some other company. I don't recognize the design of the brains module nor the fob, so I'm not sure what it's a clone of. Anyway, I rigged it up so the lock outputs (which are simply relay terminals internal to the module) to the wires that hook to the garage goor open button by the walk-in door. I took apart this button and looked at the circuit and verified that it simply "shorts" the two wires top open/close the door. Simple enough.

So, I scrounged up a small switching 12v supply, and a little bit of wiring later:



I had to wire it up so the lock and unlock wires are in parallel. Now, I have two more transmitters to open the door. The only downside is that the "lock" and "unlock" buttons work differently depending on what state the module thinks the door is in, but if pressing one button doesn't operate the door, I just press the other.

This is the key fob unit. It's quite heavy and feels surprisingly well-made for a cheap Chinese unit:



And as for security, it supposedly has rolling codes and only works with these specific transmitters, so I don't think I have to worry about people doing drive-by opener tests or sniffing the signal (I doubt 99% of the people around here even know what that means).