from machine import Pin
import neopixel
import time

LED_PIN = 16

np = neopixel.NeoPixel(Pin(LED_PIN), 1)

while True:

    np[0] = (255, 0, 0)
    np.write()
    time.sleep(0.5)

    np[0] = (0, 0, 0)
    np.write()
    time.sleep(0.5)