from machine import Pin
import utime
trigger=Pin(2,Pin.OUT)
echo=Pin(3,Pin.IN)
def ultra:
 trigger.low()
 utime.sleep_us(2)
 trigger.high()
 utime.sleep_us(5)
 trigger.low()
 while echo.value()==0: 
    signalon=utime.ticks_us()
 while echo.value()==1:
    signaloff=utime.ticks_us()
 a = signalon-signaloff
 distance=(a*0.0343)/2
 print("the distance is",distance)
while True:
    ultra()
    utime.sleep_us(1)