from hcsr import HCSR04
from machine import Pin
from time import sleep
sensor = HCSR04(trigger_pin=6, echo_pin=8, echo_timeout_us=20000)
buz = Pin(13,Pin.OUT)
while True:
    distance = sensor.distance_cm()
    print("distrance :", distance , "cm")
    sleep(0.5)
    if distance <= 100  :
        buz.value(1)
        print("buzzer ring")
        sleep(0.5)
    else :
        buz.value(0)