private void BtnDisconnect_Click(object sender, EventArgs e)
        {
            try
            {
                if (UART.IsOpen)
                {
                    while (UART.BytesToWrite > 0)
                    {
                    }
                    UART.DiscardInBuffer();
                    UART.Dispose();
                    UART.Close();

                    btnConnect.Enabled    = true;
                    btnDisconnect.Enabled = false;
                    lblStatus.Text        = "Port is closed !";
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }