Got it to work 😄. The issue was the M5.begin call. I was passing true to DisplayEnable, but I guess there is some collision, so the device can't drive the strip and the matrix display at a same time. For my project the strip alone is good enough, so disabling the display is not a problem.
#include <Arduino.h> #include "M5Atom.h" #include "Adafruit_NeoPixel.h" #define PIN 32 #define NUMPIXELS 10 #define DELAYVAL 500 Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800); void setup() { M5.begin(true, true, false); pixels.setBrightness(255); pixels.begin(); Serial.println("\nGroveLedStickTest\n"); } void loop() { pixels.clear(); for (int i = 0; i < NUMPIXELS; i++) { pixels.setPixelColor(i, pixels.Color(255, 0, 255)); pixels.show(); delay(DELAYVAL); } }