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:

    distancia = medidor.distance_cm()
    print("Distancia = ", distancia, "cm")
        
    if distancia >= 20:
        led.value(1)
        print("encendido, alerta")
    
    else:
        led.value(0)
        print("No hay nadie, todo normal")
    sleep(1)