from machine import Pin
import utime

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

def distanceSensor():
    trigger.low()        # Mute the sensor (could also use trigger.value(0))
    utime.sleep(.2)       # Sleep for .2 seconds
    trigger.high()       # Emit sound
    utime.sleep(.5)       # Sleep
    trigger.low()        # Mute

    while echo.value() == 0:  # While no echo signal
        off = utime.ticks_us()
    while echo.value() == 1:  # Once we get a signal
        on = utime.ticks_us()

    timepassed = on - off  # How long between sending a pulse and getting a return signal
    distance = (timepassed * 0.0343) / 2  # Calculate time of flight
    print("The distance is", distance, "cm")

# Simple loop to test the function
while True:
    distanceSensor()
    utime.sleep(.1)