from machine import Pin, PWM
from utime import sleep

led = PWM(Pin(15))
led.freq(1000)

while True:
    #LED irá "piscar suavemente" com efeito fade in/out.
    for i in range(0, 65536, 1000):
        led.duty_u16(i)   # Aumenta o brilho
        sleep(0.05)
    for i in range(65535, 0, -1000):
        led.duty_u16(i)   # Diminui o brilho
        sleep(0.05)