keebx: RGB LED
Part of the keebx engineering log.
WIP
Comments
IS31FL3731
6028 common anode LEDs then. For the controller the IS31FL3731 is the most common choice.
The LEDs get connected to the RGB controller in a charlieplexed matrix. That way you can drive a lot of LEDs without using too many pins on the MCU.
SoC LEDs that have a controller chip integrated into each LED like the WS2812B are unfortunately not really usable for per-key lighting since they draw too much power. They are only recommended for use with backlighting where you only have 10-12 LEDs in total.
This of course doesn't really apply if are only designing a very small macropad PCB that will only have a few LEDs in total anyways. In that case you could use SoC LEDs like the SK6812 Mini-E. They are compatible with the WS2812 data protocol.
https://www.reddit.com/r/MechanicalKeyboards/comments/lbkvv6/rgb_lighting_matrix_help/