• Hi,

    I'm trying to connect 330 WS2812B LEDs to an ESP8266, using neopixelWrite. However it doesn't seem to work above around 200 LEDs, it starts behaving oddly and turning off earlier LEDs. It looks like it might be an overflow error, could that be possible?

    I'm testing it with a really long array, which could also be the problem if Espruino has a maximum array length.


  • It was a hardware problem... I was using zener diodes every 50 or so to try to reduce the risk of ESD, but it was disrupting the signal.

  • Be careful about power... I2R losses on WS2812B 5050SMD light strips drop in voltage enough to screw the logic chip in the module after about 100-150 lights. This will manifest in odd behavior of the lights on the tail end. In particular, if you try setting and entire 300LED 5meter reel to full on white GRB=[255,255,255] you'll see soli white for about 100, then it will start to turn a warmer color as you get further down the strip, until completely off at about count 130 (these numbers are eyeballed approximations).

    Actual animated color control will see odd behavior in the tail end of the light chain, depending on how bright you're setting things.

    Bottom line: you need to bring power out and splice it in about every 100 or so lights.

  • Thanks for that, I've spliced in power every 90 lights and it seems to be holding up well, but I have yet to try to animate it.

  • Hey, I'm also playing about with an ESP and lots of WS2812b LEDs, I've made a WebSocket brightness dial, It's pretty cool to play with, but it isn't very stable :( sometimes it just stops serving any webpage. Anyway here's a Gist of the code as to not spam this thread: https://gist.github.com/MrTimcakes/6dc1c­78f27d3841e47d3125e8b515407

  • One thing I forgot to note is that the logic signal is fine as long as Vcc is taken care of as described. Due to the waveform reshaping in each 2812B, you can chain an unlimited number of them.

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Maximum number of WS2812B LEDs when using neopixelWrite

Posted by Avatar for AlexOwen @AlexOwen