from time import sleep
from machine import Pin
from machine import PWM
PWM =PWM(Pin(0))
pwm.freq(50)
  def set serv ocycle(postion):
PWM.duty_u 16(postion)
sleep(0.01)
while true:
  for pos in range (1000,900,50)
    set servo cycle(pos)
  for pos in range(9000,1000,50)  
    set  servo cycle (pos)