from utime import sleep_ms
from neopixel import NeoPixel
from machine import Pin,PWM

np=NeoPixel(Pin(23),16)
for i in range(16):
    np[i]=255,0,0
    np.write()
    sleep_ms(100)
    np[i]=0,255,0
    np.write()
    sleep_ms(200)
    np[i]=0,0,255
    np.write()
    sleep_ms(100)