You remember all the good old days when all it took to get into your best friend’s treehouse was some secret knock you all formed.  Even if you never experienced that yourself, every little kid wishes for that kind of a code.  Well now as a full grown adult, you can create a similar item that does that for your full sized house.  Don’t worry, it’s a bit more secure than just some guy standing on the other side waiting to turn the lock on your cue.

Seeing the pictures of the lock and thinking of all the possibilities is enough to get anyone excited, but seeing the device in action is enough to make any gadget lover giddy with anticipation.  The video explains a bit on how it’s made and what is used to make it.  It also shows the device detecting the knock and unlocking the door.  Some of the parts include a tiny gear reduction motor, a PVC pipe and a piezo speaker.  For those of you that need more than a quick video to figure out the project, there is also a detailed guide on how it’s done.

Source: Techeblog