from time import sleep
from machine import Pin
from machine import PWM
pwm = PWM(Pin(0))
pwm.freq(50)
def setServoCycle(Position):
  pwm.duty_u16(Position)
sleep(0.01)
while True:
   for Pos in range(1000,9000.50):
     setServoCycle(Pos)
   for Pos in range(9000,1000,-50):
     setServoCycle(Pos)