from hcsr04 import HCSR04
from time import sleep
from machine import Pin
led = Pin(12, Pin.OUT)
sensor = HCSR04(trigger_pin=15,echo_pin=4)
while True:
distance = sensor.distance_cm()
print("Khoảng cách: ", distance, " cm")
if distance < 20:
led.value(1)
else:
led.value(0)
sleep(0.1)