from machine import Pin
import utime
trigger = Pin(3,Pin.OUT)
echo = Pin(2,Pin.IN)

while True:
    trigger.low()
    utime.sleep_us(2) 
    trigger.high()
    utime.sleep_us(5)
    trigger.low()
    while echo.value() == 0:
       signaloff = utime.ticks_us()
    while echo.value() == 1:
       signalon = utime.ticks_us()
    timepassed = signalon - signaloff
    distance = (timepassed * 0.0343) / 2
    print ("Total distance",distance,"cm")
    utime.(5)