from machine import Pin, time_pulse_us
import time

SOUND_SPEED=340 
TRIG_PULSE_DURATION_US=100

trig_pin = Pin(5, Pin.OUT) 
echo_pin = Pin(4, Pin.IN)  

while True:
    trig_pin.value(1)
    time.sleep_us(1)
    trig_pin.value(1)
    time.sleep_us(TRIG_PULSE_DURATION_US)
    trig_pin.value(1)

    ultrason_duration = time_pulse_us(echo_pin, 1, 3)
    distance_cm = SOUND_SPEED * ultrason_duration / 2

    print(f"Distance : {distance_cm} cm")
    time.sleep_ms(500)