Advice on 2020-sized SK and APA variants

Ideas and Tips
1

I am thinking of using individual 2020-sized leds for wearable projects. I’m looking for advice and things I should be aware of regarding the various types available (likely from Aliexpress).

  • The leds will be part of meshes/tiled patterns, likely embedded in 3D-printed parts. For concreteness, imagine a pattern of 1-inch flat printed hexagons on a fabric backing.
  • I plan on designing a minimally-sized carrier PCB so I can connect them all with thin gauge wire (I haven’t found a 2020-sized breakout PCB).
  • I am leaning towards 3-wire to reduce the amount of soldering involved. 3-wire will probably mean poor performance at low brightness levels, but considering they will be illuminating 3D printed plastic from the inside, it might be acceptable to run them at a higher brightness—power will come from a 10,000 mAh USB battery pack.
  • Alternatively, I could just bite the bullet and design a 4-wire carrier PCB and not worry about colors at low brightness.

Here’s an example listing of SK6805 2020s (APA102 also available).

Is there anything I should be aware of in terms of different 5 V SK and APA variants? Or can I assume as long as they’re 3/4-wire and 5 V, they’re all the same?

Thanks!

2

I don’t have PCB design experience, but one thing I’ve observed is that I’ve never seen these pixels in a form factor that puts more than a centimeter between adjoining pixels. The way I’ve used them is on very tight 240/m metal backed strips.

I think the takeaway is that I don’t know if the signal propagation / regeneration works as well as their 5050 sized cousins. Something to test early. At least with the APA102s, you can reduce the clock and data speed later, even to speed slower than SK6805s.