Love this capability, bought a bunch.  Have a small issue with voltage drop across units causing the unit to dim each time i an another to the chain. Pls advise if possible

What chip is used in the RGBW "neopixels"?  That ought to cut the need down to two chips/digit?

Great project.  I've been doing a 4H project with serial addressable LEDs and Arduino.  This will be a great follow on project.  Will you sell just the parts in PCB, kids like to do the soldering with help of course, SMD not a problem.

I'll give my first born child if this were for 16/17 segment displays.

The WS2811 chips only have three PWM outputs per chip. At about 40ct per chip and six WS2811 per segment, that would be a little expensive after a short while. I personally would just go for 74HC595 Shift Registers, giving each segment two of those so that you don't need to multiplex. No PWM, but it'd be cheaper and easier on the MCU.

Expensive? :cough: https://www.aliexpress.com/item/Free-shipping-100pcs-lot-WS2811S-WS2811-SOP-8-IC-best-quality/32810984795.html

@Keith Olson Unless of course one is smart enough to check Aliexpress or LCSC. I'm just too used to Digikey, which only sell a ten-pack for the same price as the 100-pack there, so thanks for the recommendation! Makes me want to use an unjustified amount of these in personal projects :>

Heh.  Me, too!  I suddenly find myself considering building 100cm-high, 16 segment displays using six of those each.

Ahhh, this is awesome!
I actually had forgotten that you can get the WS2811 as a separate chip. I've been working with WS2812 in their "all-in-one" LED package a bit too much. This almost makes me wonder how small you could get one of those 7 Segment drive chips ...

In any case, I do know a little bit about writing Arduino libraries, as well as plenty of C++ code, and together with the Adafruit library for driving NeoPixels in general, it'd be pretty easy to write up a library for that stuff!

I also already worked on a few transition effects for my New Year's eve countdown clock, maybe those, in a simpler fashion, could be added to the library!

Hey Sean, great idea. Seems like this will be super useful. Thanks!