I found a really cool mod during a bout of Stumbling. It is by a guy named Steve Hoefer who according to his site, Grathio Labs, is a globally recognized inventor and creative problem solver based in San Francisco. In this video Steve gives us his Secret Knock Detecting Lock that will unlock your door if you provide the correct knocking sequence, and the correct tempo.
You can build this cool little contraption yourself by following Steve's instructions on The Instructables website here: (How To Build A Secret Knock Detecting Door Lock)
Steve also describes his invention in more in depth on his website as well. From his article:
The Secret Knock Detecting Lock unlocks your door when it detects the correct knocking sequence. It's the perfect accessory to your secret lair, club house or tree house. It has gotten worldwide attention and the video has been seen well over half a million times. A ton of people have been inspired by this project and expanded and adapted it. Its simplicity and cleverness has also encouraged thousands of people to get started exploring the world of microcontrollers.
You can check out the video below:
I'm not sure that I would trust my most prized possessions with a locking mechanism of this type. I mean someone with a sound amplification device could be staked outside of your apartment where you can't see them to hear your knocking combination. In fact, you can get one of those listening devices pretty cheap on Amazon. The one pictured below is less than $100 (Click the picture to visit the product on Amazon)
Still though, pretty cool right? Are you going to try to build one? If you do, let us know how it goes in the comments!