from time import sleep
from machine import Pin
from machine import PWM
pwm = PWM(Pin(2))
pwm.freq(100)
def servo (position):
  pwm.duty_u16(position)
  sleep(0.01)
while True:
   for pos in range(1000,1000,10):
    servo(pos)
   for pos in range(9000,1000,-10):
    servo(pos)