The knock-activated noisy box

This project was intended as a prank; when I was thinking about the uses of a knock sensor I thought it would be funny to use it to make a doorbell. The thing you see is a small box that produces a funny chirping noise when you knock or shake it. It is intended to be attached to a door, or some other moving object. Not really an Arduino project since it uses only basic electronic components, but still it was quite entertaining to make and it’s a chance to have fun with analog electronics!

Read ahead to see instructions on how to make one!

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