2018.4.38

def checkdist():
    GPIO.output(IN5,GPIO.HIGH)
    time.sleep(0.000015)
    GPIO.output(IN5,GPIO.LOW)
    while not GPIO.input(IN6):
        pass
    t1 = time.time()
    while GPIO.input(IN6):
        pass
    t2 = time.time()
    return (t2-t1)*340/2