#SENSOR ULTRASONIC
from machine import Pin 
from hcsr04 import HCSR04
from time import sleep

medidor = HCSR04 (trigger_pin = 4, echo_pin = 5)
led = Pin (2, Pin.OUT)

while (True):
    try:
        distancia = medidor.distance_cm()
        print("distancia = ", distancia)
        if distancia >= 20:
            led.value(1)
            print("Encendido, alerta")
        else:
             led.value(0)
             print("No hay nadie")
        sleep(1)
    except:
     print(error)