What else can be built of all printer that refuses to print? Useless machine sounds good enough. Therm “useless machine” is around for some time and it represents a device which simply tries to turn off itself when someone switches it on. Many hobbyists are making these machines that do does this on one or another way.
This one is a bit different because it has eight switches instead of one. Since printer head position motor and encoder were still in tact and encoder chip (Agilent AEDS 9621P) seemed to be easily interfaced to microcontroller it became pretty easy access all switches with resolution 327 steps/cm. The useless machine is controlled by Atmega8 microcontroller which plays whole thing.