from machine import Pin, time_pulse_us
import time

trig = Pin(4, Pin.OUT, value=0)
echo = Pin(2, Pin.IN)


def distance():
    trig.value(1)
    time.sleep_us(10)
    trig.value(0)
    us = time_pulse_us(echo, 1, 23200)
    if us < 0:
        return us
    else:
        cm = round(us / 58, 1)
        return cm


while True:
    cm = distance()
    print(cm)
    time.sleep_ms(1000)