from time import sleep 
from machine import Pin
import time

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

def ultrasonic():
    trigger.low()
    time.sleep_us(2)
    trigger.high()
    time.sleep_us(5)
    trigger.low()
    while echo.value() == 0:
        signaloff = time.ticks_us()
    while echo.value() ==1:
        signalon = time.ticks_us()
    timepassed = signalon - signaloff
    distance = (timepassed * 0.0340)/2
    return distance
while 1:
    time.sleep(1)
    print(ultrasonic())