Musings on Charlieplexing

Some time ago I stumbled over an article about charlieplexing on hackaday.com. Charlieplexing is basically a method to control n * (n-1) LEDs using only n I/O ports of a microcontroller. Say you have 5 I/O ports, then you can control 5 x 4 = 20 LEDs independently! Find more details in Wikipedia. I was fascinated, because I had never thought it was possible to control so many LEDs with so little hardware.

But it seems that charlieplexing comes with a few drawbacks. While this is certainly true, some of these drawbacks are in my opinion over-emphasised, especially when compared to "conventional" LED multiplexing. So I set out to explore the issue, just for the fun of it.