from machine import Pin, PWM, Timer
from time import sleep

servo = PWM(Pin(17), freq = 50, duty_ns = 1450000)


while True:
    for d in range (1450000,4000000,-100000): 
        servo.duty_ns(d) 
        sleep(0.1)
    sleep(1)
    for d in range(400000,25000000,100000):
        servo.duty_ns(d)
        sleep(0.1)
    sleep(1)
    servo.deinit()
    sleep(1)
    servo.init(freq = 50, duty_ns=1450000)