from time import sleep
from machine import Pin,PWM

pwm  = PWM(Pin(1))
sw = Pin(10,Pin.IN)
pwm.freq(50)
#pwm.duty_u16(1000)

while True:
    if sw.value()==1:
        for position in range(1000,9000,50):
            pwm.duty_u16(position)
            sleep(1)
        
    else :
        for position in range(9000,1000,-50):
            pwm.duty_u16(position)
            sleep(1)