import time 
import board 
import adafruit_hcsr04
import digitalio
import pwmio

trig_pin=board.GP22
echo_pin=board.GP21
sonar=adafruit_hcsr04.HCSR04(trig_pin,echo_pin)

buzzer= pwmio.PWMOut(board.GP0,frequency=1000)


while True:
    try:
        distance=sonar.distance
        print('Distancia: {:.1f} cm'.format(distance))
        time.sleep(0.1)
        if sonar.distance < 100.0:
            buzzer.duty_cycle= 32000
        else:
            buzzer.duty_cycle=0

    except RuntimeError:
        print('Retrying...')
        pass