from machine import Pin
import utime

trigger = Pin(2, Pin.OUT)
echo = Pin(3, Pin.IN)

sound = 340 * 100  # m/s * centi = cm/s


def ultra():
    trigger.low()
    utime.sleep_us(2)
    trigger.high()
    utime.sleep_us(10)
    trigger.low()

    # echo goes high as soon as sound wave is sent
    #   and returns to low once sound gets back
    while echo.value() == 0:
        sent_time = utime.ticks_us()  # us

    while echo.value() == 1:
        received_time = utime.ticks_us()  # us

    delta_time = received_time - sent_time  # us
    distance = delta_time / 1_000_000 * sound / 2
    print("The distance from object is", distance, "cm")


while True:
    ultra()
    utime.sleep(0.1)