from machine import Pin,PWM
import utime

def main():
    pwm0 = PWM(Pin(28), freq=2000, duty_u16=0)
    pwm1 = PWM(Pin(27), freq=2000, duty_u16=0)
    pwm2 = PWM(Pin(26), freq=2000, duty_u16=0)

    while True:
        for i in range(0, 65535):
            print(i)
            pwm2.duty_u16(i)
            utime.sleep_ms(1)
        utime.sleep(1)
        for i in range(65535, -1,-1):
            print(i)
            pwm2.duty_u16(i)
            utime.sleep_ms(1)
        utime.sleep(1)
        
if __name__== '__main__':
    main()