LEAP#229 Dice

This is my deluxe version of a 555/4017-based dice circuit. It’s got slow-down and auto power-off, but is also craftily packed into a cube. All the inards are exposed, but I think that’s a good thing. Perhaps the next step would be to cast it in clear resin? As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image

This project is a combination of circuit ideas. It breaks down into 5 main systems:

  • Counter: The 555 timer and CD4017 provided a clocked 1-of-6 line output
  • Die Display: A network of steering diodes and transistors decode the 6 outputs to a 7-LED conventional dice display
  • Counter roll & slowdown: An RC network and high-side PNP switch slow the counter speed over time until the “roll” stops
  • Auto Power-off: a p-channel MOSFET with RC timer cuts the circuit power after the roll
  • Trigger: a mercury switch simulates a “shake”

Here’s a quick video of the dice in action: