Callback for data received from the copter.

def _incoming(self, packet):
        """
        Callback for data received from the copter.
        """
        if len(packet.data) < 1:
            logger.warning('Localization packet received with incorrect' +
                           'length (length is {})'.format(len(packet.data)))
            return

        pk_type = struct.unpack('<B', packet.data[:1])[0]
        data = packet.data[1:]

        # Decoding the known packet types
        # TODO: more generic decoding scheme?
        decoded_data = None
        if pk_type == self.RANGE_STREAM_REPORT:
            if len(data) % 5 != 0:
                logger.error('Wrong range stream report data lenght')
                return
            decoded_data = {}
            raw_data = data
            for i in range(int(len(data) / 5)):
                anchor_id, distance = struct.unpack('<Bf', raw_data[:5])
                decoded_data[anchor_id] = distance
                raw_data = raw_data[5:]

        pk = LocalizationPacket(pk_type, data, decoded_data)
        self.receivedLocationPacket.call(pk)