im working on a project with an 144 LED/m strip driven by an Adafruit ItsyBitsy M0 Express. To test the LED strip I connected it directly to the ItsyBitsy driving only 5 LED's. Now I'm trying to run a test program but only the 5 previously declared LED's light up and stay that way. setPixelsColor or setBrightness has no effect whatsoever. Hope someone has an idea.

Here the test program

#include <Adafruit_NeoPixel.h>

#define NUMPIXELS 5
#define PIXELPIN 5

Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUMPIXELS, PIXELPIN, NEO_GRB + NEO_KHZ800);

void setup() {



void loop() {
  strip.setPixelColor(2, 255, 0, 255);
  strip.setPixelColor(2, 0, 0, 0);
  • In my Neopixel code I don't set the data pin as output. Though I don't know, if this is even a problem. – chrisl May 5 '18 at 14:26
  • Did you mean only 5 of 144 leds are lit? – Mert Gülsoy May 6 '18 at 22:06
  • Yes I only declared 5 LED's so the current on the pin won't be to high – Zeg du Toit May 7 '18 at 7:26

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