def wait_for_interface():
    print("Waiting for interface: {} to become available . . .".format(self.interface))
    i = 0
    while i < timeout or timeout == -1:
        if os.path.exists(self.interface):
            print("Successfully bound to: {}.".format(self.interface))
            on_connect_callback()
            return
        i += 1
        time.sleep(1)
    print("Timeout({} sec). Interface not available.".format(timeout))

def read_events():
    try:
        return _file.read(self.event_size)
    except IOError:
        print("Interface lost. Device disconnected?")
        on_disconnect_callback()