import time
import board
import neopixel

pixels = neopixel.NeoPixel(board.A3, 5*5, brightness=0.5, auto_write=True)

for i in range(50):
    pixels.fill((50, 0, 0)) # red
    time.sleep(0.5)
    pixels.fill((0,0,50)) # blue
    time.sleep(0.5)
    print(i)