Here’s a fun hack that uses a Nintendo controller, Arduino, and CD drive to create a fun, keyless entry system.
Use a Classic Nintendo controller to lock and unlock your door! The output from the Controller is read by an arduino and it looks for a particular combination of buttons, once the combination is entered it sends a signal to eject a Cd-Rom Drive which pushes or pulls the lock. I started making this project like I always do; with what I have on hand. So if you have the same stuff lying around it can be assembled for very little cost.