from machine import Pin
import time
trig=Pin(18,Pin.OUT)
echo=Pin(19,Pin.IN)
while True:
trig.off()
time.sleep_us(2)
trig.on()
time.sleep_us(2)
trig.off()
while echo.value()==0:
siga=time.ticks_us()
while echo.value()==1:
sigb=time.ticks_us()
tm=sigb-siga
d=(tm*.0343)/2
print(d)
time.sleep(1)