from machine import Pin, PWM
import time

servo = PWM(Pin(15))
servo.freq(50)

while True:
    for position in range(1000, 9000, 50):
        servo.duty_u16(position)
        time.sleep(0.01)

    for position in range(9000, 1000, -50):
        servo.duty_u16(position)
        time.sleep(0.01)