from machine import Pin
from time import sleep
from neopixel import NeoPixel

ring = NeoPixel(Pin(0), 16)
color = (255,0,0)
off = (0,0,0)

for i in range(0,16):
    ring[i] = color
    ring.write()
    sleep(1)
    ring[i] = off
    sleep(1)