private void readPortandShow()

        {

            char[] HexChar = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };

            byte receivebyte = (byte)serialPort1.ReadByte();

            char hexH = HexChar[receivebyte / 16];

            char hexL = HexChar[receivebyte % 16];

            this.tBox.Invoke(new MethodInvoker(delegate

                {

                    this.tBox.AppendText(hexH.ToString() + hexL.ToString() + " ");

                }));

        }