#include <Adafruit_NeoPixel.h>

#define LED_PIN    2
#define LED_COUNT 16

Adafruit_NeoPixel ring(LED_COUNT, LED_PIN, NEO_RGBW + NEO_KHZ800);

void setup() {
  ring.begin();           
  ring.show();            
  ring.setBrightness(50); 
}

void loop() {
  for(int i = 0; i < ring.numPixels(); i++){
    ring.setPixelColor(i, random(255), random(255), random(255), 0);
    ring.show();
    delay(50);
  }
  for(int i = ring.numPixels()-1; i >= 0; i--){
    ring.setPixelColor(i, 0, 0, 0, 0);
    ring.show();
    delay(50);
  }
}