from machine import Pin, PWM
import time

servo=PWM(Pin(5))
servo.freq(50)

while True:
  for pulso in range(500000, 2500000, 1000):
    servo.duty_ns(pulso)
    time.sleep_ms(1)

  for pulso in range (2500000, 500000, -3000):
    servo.duty_ns(pulso)
    time.sleep_ms(1)