Hack a 12-DIP garage door opener remote
Okay, so after getting the pcb, You'll need twelve TLP621 optocouplers, an arduino(nano), two sets of headers (12 long each), soldering and desoldering equipment, and a garage door opener with a 12-dip encoding system.
After soldering the parts in the schematic to the pcb, you desolder the 12-DIP switch and attach each set of two pins to their respective numbered header with either hookup wire, or jumpers. The next step is to short the button on the remote such that it is always on. This way, the remote will go through all of the codes and test them all, without you having to hold the button down.