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SK6812away

Re:Building DIY LED strips for fun on Sunday July 19, 2020 @10:51PM (#23894256)
Hey, keep it up. I'd be very embarrassed if any of my blog posts ended up on HN, too.

You'll get there! :)

Re:Building DIY LED strips for fun on Sunday July 19, 2020 @10:44PM (#23894223)
IME, you can use 3.3V logic with 5V WS2812B/SK6812 strips, no trouble.

Each LED reforms the signal before sending it to the next LED in the chain, so voltage dropping over distance shouldn't a huge issue for the logic line unless the strip is very far away from the controller.

And the datasheet almost agrees with my experience; the "high" voltage threshold is listed as 0.7×VDD, and 0.7×5=3.5V. That's a bit over 3.3V, but I haven't had any issues across several projects. Maybe it's because many USB supplies provide a little over 5V to account for droop? Maybe the datasheet is slightly pessimistic? Maybe 0.7 really means 2/3? Whatever the reason, it simplifies the wiring for small displays.

Here's my favorite reference for the single-wire protocol that these LEDs use, since everyone seems to be chiming in with one:

https://wp.josh.com/2014/05/13/ws2812-neopixels-are-not-so-f...