from time import sleep 
from machine import Pin,PWM

PWM = PWM(Pin(0))
PWM.freq(50)

def setServoCycle (position):
    PWM.duty_u16(position)
    sleep(0.01)

while True:
  for pos in range(1000,9000,1):
      setServoCycle(pos)
  for pos in range(9000,1000,-1):
      setServoCycle(pos)