This instructable is less a build you’re own project and more a description of the theory of charlieplexing. It’s suitable for people with the basics of electronics, but not complete beginners. I’ve written it in response to the many questions I’ve gotten in my previously published Instructables.

What is ‘Charlieplexing’? It is driving lots of LEDs with only a few pins. In case you’re wondering Charlieplexing is named after Charles Allen at Maxim who developed the technique.

This can be useful for lots of things. You may need to display status information on a small microcontroller, but only have a few pins spare. You may want to show a fancy dot matrix or clock display but don’t want to use lots of components.

Some other projects demons…

By: rgbphil

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