On the Question of Electronic Dice & Charlieplexing
Sometimes you might wonder about driving an array of LEDs with just a few number of I/O pins – either because that’s all that’s available or because you want to challenge yourself to figure it out. Charlieplexing is one solution and this post will help you think through the basics of it, using electronic dice to explain the concept:
I recently bought a very low cost electronic dice kit on an impulse. Assembling it was good retro-fun for a while. The circuit design is was purely 70ies style: A CD4017, a NE555 and a couple of transistors. Of course, this got me thinking: How would it be done today in a most efficient way? Of course this means using a microcontroller, and, of course this means using as few resources as possible. Will an ATiny10 with 3 I/Os pins do?