Roll the eDice!

During my miss spent youth I've built quite a few electronic projects, not all of which worked. One of the early ones that did work was an electronic dice. Well, worked after a fashion: the schematics called for a seven segment display, but the boys at the local radioschack sold me a bar of seven LEDs! No wonder I never rolled a one...the schematics are on the left, if you are interested.

Later I've built atleast three more to my own design. Unfortunatelly I have no photos or schematics any more...except this one, which was designed to be used by my father in his teaching job. Chrisse had designed one that had remarkably few parts, however, it displayd the number two not diagonally as a proper dice should, but horizontally. That just was not good enough for me.

So I started to play around with the idea and came up with this design, Chrisse put in the finalising touches; the schematics are his handwriting. He innovted the auto-off desing and the gradually slowing roll action. The design features:

• auto off
• 'real' dice patterns
• gradual slow-down
• few parts
• just two ICs
• syncronous desing

The one in the animation still runs after some eight years. It was built by my daughther Sandra with some help from me. Below you see the original prototype.

Kusti, 1.9.2004

P.S.

This design actually has one flow. Can you spot it? The dice is more likely to stop at some numbers than others because because the current consumption of the LEDs modula the thresshold of the NAND-gate that functions as the oscillator. To cure that it is necessary to add a power supply regulator.