from machine import Pin
from neopixel import NeoPixel
import time

button = Pin(13, Pin.IN, Pin.PULL_UP)

pixel_pin = 22
pixel_count = 16

pin = Pin(pixel_pin, Pin.OUT)
np = NeoPixel(pin, pixel_count)

def on():
    for i in range(pixel_count):
        np[i] = (255, 20 + i * 10, 147 + i * 5)
        np[15 - i] = (255, 245 - i * 10, 245 - i * 5)
        np.write()
        time.sleep(0.2)


def off():
    np.fill((0, 0, 0))
    np.write()

while True:
    if not button.value():
        on()
    else:
        off()
    time.sleep(0.2)