コード例 #1
0
        public byte[] GetBytes(ButtonMessage message)
        {
            //set the sequence
            message.SequenceID = (byte)_sequenceID++;

            //set checksum
            message.Checksum = CalculateChecksum(message);

            return(ConvertToByte(message));
        }
コード例 #2
0
        ushort CalculateChecksum(ButtonMessage message)
        {
            //payload_len: The actual length of the packet
            //subtracting 2 here, to remove checksum from len
            //else we will end up computing checksum of the checksum
            ushort checksum = 0;

            checksum += (ushort)message.PacketID;
            checksum += (ushort)message.ErrorID;

            foreach (var d in message.Payload)
            {
                checksum += (ushort)d;
            }

            return(checksum);
        }
コード例 #3
0
        ButtonMessage ParseMessage()
        {
            var result = new ButtonMessage();
            int index  = 0;

            result.StartOfFrame = packet_buffer[index++];

            if (result.StartOfFrame != SOP)
            {
                return(null);                //Invalid SOP
            }
            result.PacketID   = packet_buffer[index++];
            result.ErrorID    = packet_buffer[index++];
            result.SequenceID = packet_buffer[index++];

            int index2 = 0;

            result.Payload = new byte[packet_size - index - 3];
            for (; index < packet_size - 3; index++)
            {
                result.Payload[index2++] = packet_buffer[index];
            }

            result.EndOfFrame = packet_buffer[index + 2];

            if (result.EndOfFrame != EOP)
            {
                return(null);                //Invalid EOP
            }
            //correct checksum (to big endian)
            result.Checksum = BitConverter.ToUInt16(new byte[] { packet_buffer[index + 1], packet_buffer[index] }, 0);

            //verify checksum
            var check = CalculateChecksum(result);

            if (check != result.Checksum)
            {
                return(null);                //Invalid Checksum
            }
            return(result);
        }
コード例 #4
0
        Byte[] ConvertToByte(ButtonMessage message)
        {
            var index  = 0;
            var result = new byte[message.Payload.Length + 7];

            result[index++] = message.StartOfFrame;
            result[index++] = message.PacketID;
            result[index++] = message.ErrorID;
            result[index++] = message.SequenceID;
            foreach (var data in message.Payload)
            {
                result[index++] = data;
            }
            var checksum = BitConverter.GetBytes(message.Checksum);

            result[index++] = checksum[1];
            result[index++] = checksum[0];
            result[index++] = message.EndOfFrame;

            return(result);
        }