Piecax The Poltergeist Reinvents The Knock Block


[AndyGadget] built a haunted box as part of his Halloween preparations. This follows in the footsteps of the Knock Block we saw earlier this month but makes several hardware changes. He’s replaced the solenoid with a DC motor that rotates an arm to do the knocking. He’s avoided any CNC work by using a softwood box from a craft store as the enclosure. For control circuitry he’s used an 8-pin PICAXE Microcontroller that ‘listens’ for knocking on the box via a piezo buzzer. It will mimic knocks back to you, and if it hears the right combination The Addams Family theme song is played. This useless machine will make a great office conversation piece and with this simplified design it’s much easier to build than the Knock Block. See it perform after the break.


13 thoughts on “Piecax The Poltergeist Reinvents The Knock Block

  1. Cool design, made me larff when it did the knocks thru the addams family song.
    One little thing tho – the wristwatch beep sound kind of ruins the effect doesn’t it? I wonder if an ISD chipcorder would sound less corny.

  2. I think it would be even better if, rather than playing the whole theme with a beeper like that, it plays the song just as beats with the solenoid. When it gets to the bridge, it wouldn’t continue until you provide it with the two taps. Much more interactive

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