M5-ProductExampleCodes/Module/FACESII_NeoPixelTest/FACESII_NeoPixelTest.ino

/*
 neo pixel test

   hardwware:  M5StackFire 

 please install the Adafruit library first!
 September 2018, ChrisMicro
*/

#include <Adafruit_NeoPixel.h>

#define M5STACK_FIRE_NEO_NUM_LEDS 10
#define M5STACK_FIRE_NEO_DATA_PIN 15

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(M5STACK_FIRE_NEO_NUM_LEDS, M5STACK_FIRE_NEO_DATA_PIN, NEO_GRB + NEO_KHZ800);

void setup()
{
  pixels.begin(); 
}

void loop()
{

  static int pixelNumber=0;// = random(0, M5STACK_FIRE_NEO_NUM_LEDS - 1);
  pixelNumber++;
  if(pixelNumber>9)pixelNumber=0;
  int r = 1<<random(0, 7);
  int g = 1<<random(0, 7);
  int b = 1<<random(0, 7);

  pixels.setPixelColor(pixelNumber, pixels.Color(r, g, b));     
  pixels.show();

  delay(100);

}