Initializes the device with the corresponding serial or device number.

        :param int or None serial: Serial number of the USB-CANmodul.
        :param int device_number: Device number (0 – 254, or :const:`ANY_MODULE` for the first device).

def init_hardware(self, serial=None, device_number=ANY_MODULE):
        """
        Initializes the device with the corresponding serial or device number.

        :param int or None serial: Serial number of the USB-CANmodul.
        :param int device_number: Device number (0 – 254, or :const:`ANY_MODULE` for the first device).
        """
        if not self._hw_is_initialized:
            # initialize hardware either by device number or serial
            if serial is None:
                UcanInitHardwareEx(byref(self._handle), device_number, self._callback_ref, None)
            else:
                UcanInitHardwareEx2(byref(self._handle), serial, self._callback_ref, None)
            self._hw_is_initialized = True