23 October, 2012

A Useless Machine with delay and howl

The useless machine or ultimate machine originates from Claude Shannon, the scientist who figured out how to find the channel capacity in a communications system. I bought the basic machine as a kit from Solarbotics.

But then I added a few features:
  • A delay circuit that makes it look more alive as it gives the impression of doing some thinking before it responds to the switch.
  • Sound that varies with how open the lid is and the amount of light that hits the photosensitive resistor. It was inspired by the design of the Growl and Scream Altoids of FightCube.
  • A couple of LEDs, a red one when it opens and a blue one when it closes.
The circuits were built on small pieces of veroboard and the circuit diagram can be downloaded from here. In retrospect I'm not completely happy with the sound, it could have growled and screamed even more, but then how much effort can one really justify putting into a project which is - useless - anyway?


  1. Hello Sverre, thanks for the funny video. 73, Bert

  2. You can never say its useless not until you don't taker advantage of it though.

  3. hello, I know how you managed to create a second delay?
    I can not do it, I'm not an electronics expert like you

  4. I am sorry but the link to the schematic seems to have vanished. I have updated the article above and also put the link here. You will find the delay circuit there.