#include <Adafruit_NeoPixel.h>
int PIN = 12;
int N_LED = 16;

Adafruit_NeoPixel ring = Adafruit_NeoPixel(N_LED, PIN);

void setup() {
  // put your setup code here, to run once:
 ring.begin();
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int i = 0; i < N_LED; i++){
    ring.setPixelColor(i, ring.Color(0,0,255));
    // draw the new pixel
    ring.show();
    delay(500);

    ring.setPixelColor(i, ring.Color(0,150, 150));
    ring.show();
    delay(500);

  }
  delay(10); // this speeds up the simulation
}