private byte[] WriteData(byte[] command, bool ack = true, int retries = 5)
    {
        byte[] ackBuffer = new byte[2];
        bool done = false;

        while ((!done) && (retries-- > 0))
        {
            Port.Write(command, 0, command.Length);

            if (ack)
            {
                while (Port.BytesToRead != 2) { Task.Delay(1).Wait(); }
                Port.Read(ackBuffer, 0, 2);

                done = 0xEE07 != (ackBuffer[0] << 8 | ackBuffer[1]);
            }
            else
                done = true;
        }

        if (!done)
            throw new Exception("WriteData retries exceeded");
        return ackBuffer;
    }

    private byte[] ReadData(byte[] command, int readLength)
    {
        byte[] headerBuffer = new byte[2];
        byte[] returnBuffer = new byte[readLength];

        Port.Write(command, 0, command.Length);

        while (Port.BytesToRead != 2) { Task.Delay(1).Wait(); }
        Port.Read(headerBuffer, 0, 2);

        if (headerBuffer[0] != 0xBB)
            throw new Exception(string.Format("ReadData error 0x{0:x2}{0:x2}", headerBuffer[0], headerBuffer[1]));
        if (headerBuffer[1] != readLength)
            throw new Exception(string.Format("ReadData error: failed to read {0} bytes.  Read {1}", readLength, headerBuffer[1]));

        while (Port.BytesToRead != readLength) { Task.Delay(1).Wait(); }
        Port.Read(returnBuffer, 0, readLength);

        return returnBuffer;
    }