After 24 days of running to the front door whenever I thought I heard the sound of the postman, my Arduino micro controller finally arrived. Actually, to be more precise I had to go fetch it because the parcel was too big to fit through the mail slot. Apparently, the postman came one week earlier while I was out and left a note saying I had to go pick it up at the post office. I never received that note and have been living a life of recurring disappointment for nothing! Anyway, I have it now and it is even more fun than I expected!


After doing the first programme ‘Hello World’ of the blinking light, I thought I’d live out my lifelong dream of clapping my hands to switch a light on and off. So with the help of the ‘knock’ tutorial from the Arduino website I got it done.

You can watch the video of my contraption in action below.


Here’s where I got my inspiration from:

Today I also had the fantastic opportunity to attend a one-day workshop on hardware hacking run by Chris Hand. I bought a £2 keyboard from a charity shop and circuit bent it. By circuit bending electronics, you can get some unintended sounds and behaviors. I unfortunately don’t have a recording of it, but it wasn’t tremendously exciting.


I guess this opens up a new category: { sound + arduino }

6 Responses to “Clap on, Clap off { sound + arduino }”  

  1. 1 wolfgang muller

    i’m glad you’ve fulfilled your lifelong dream…the clapper thingy is seriously cool though. it be awesome for the TV though, especially since i continuously misplace the remote.

  2. 2 edu

    hehehehehee, hardware hacking just rocks, the other day I “hack” the smoke detector in my room, basically I attached a screwdriver to a stick and hitted continuously the small blipping speaker of the detector untill the “blip” became a tiny “tick” not anoying at all. soo that was hacking, hahahhahaa, or signal processing?? don’t know yet…


  3. 3 Andrew

    I love it…

  4. 4 Andrew

    Wolf, it’s easier if you just tie a little cable between your remote and your sofa.

  5. 5 Chris

    Wow, nice.

    However isn’t a threshold from the knock tutorial just a reading of the volume of all sound. Wouldn’t you have to analyze the sound to detect it is a clap not just a loud noise? is this what you have done, if so are you against sharing your code?

    Nice work anyway, I am eager to experiment myself however I don’t have the skills to analyze sound like that.

  6. 6 Andrew Spitz

    Hey Chris, you’re right, it’s just reading volume. This is basic stuff that you can get from the tutorials. It was my first little Arduino thing I did. So there’s no FFT analysis going on (to find a clap), it’s purely volume based.

    If you bring the Arduino into Max/MSP:, then it is easier to analyze the sound and decipher a clap from other sound sources. For that you’d use an external called [bonk~], which you can find here:

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