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

num_of_pixels = 12 
ring_pin = Pin(14, Pin.OUT)
ring = NeoPixel(ring_pin, num_of_pixels)
white = [200, 200, 200]
off = [0,0,0]
def np_handler(np, color, number):
    np[number] = color
    if number > 0 :
        np[number-1] = off
    else:
        np[num_of_pixels - 1] = off
    np.write()

while True:
    for i in range(num_of_pixels):
        np_handler(ring, white , i)
        sleep(1)