pastaclub

You still need driver ICs, but they are already integrated into the LEDs. So the PCB gets simpler but you have one controller per LED, so with 36 LEDs you‘re paying for 36 controllers. “Tons of shift registers“ is exaggerated. Microcontrollers like the ATtiny88 already have 28 GPIOs, so up to 26 or so you wouldn‘t need any shift registers. If you opt for a small controller plus shift registers, it still would only be 1/8 or 1/16 of the number of LEDs, which isn’t tons. You‘re right about the resistors, but with industrial PCBA that shouldn’t be an issue. Your pre-connected break-away approach is awesome and makes it very versatile. And it‘s great to see a finished project. That thread on the german forum has been there for years, received many replies but nobody has shown working hardware before.

That makes sense if you want RGB functionality. I personally would be happy enough with single color LEDs, especially in a design with many encoders, due to cost. Resolution of course needs to be much higher than only 8 LEDs, so it seems a good candidate for DIY as well... and for PCBA since it’s quite boring to place so many components. Speaking of resolution, there aren’t any affordable encoders with more than 24 positions per rotation, right?

I also wonder what led to the decision to use these very pricy LEDs, especially since so many are needed. Wouldn’t it have been much cheaper to design the PCB for regular plain SMD LEDs and add a simple microcontroller per encoder with enough pins to drive all LEDs? (maybe I just didn’t understand yet why RGB LEDs are needed)