Want to drive more LEDs with fewer IO pins? Then you might be interested in the Charlieplexing technique. I’ve written an example sketch can drive six LEDs each with 8-bit PWM using the three IO pins on the Adafruit GEMA microcontroller and is a fairly easy sewable LED sequin project since there are no crossed wires when it is stitched with conductive thread. Enjoy the short video of it in action below and read on for more details…