The Arduino driven setup monitors vibrations on the lid. When you knock on the box, it records the pattern and plays it back using the solenoid. He was inspired by a knock-detecting door lock .

The Method For Creating A One-Of-A-Kind Wooden Box In No Time. ... The lid fits perfectly because it is cut from the completed box ... After angling the long edges of all four box sides with 45 ...

The clicking mechanism is created entirely by wooden parts. [dynamic music] [box clicking] ... It was a very secretive sliding-lid box. So I carried that thought with me all the way to college.

One of these items, a wooden box with the lid still firmly in place, has finally been opened, revealing its precious contents. Bits of beeswax. Yep, the wooden box was holding a plain old candle.