Using WPF like a serial monitor of Arduino IDE.

• Select a serial port from a combo box.

• Push "connect" button, write a character in a upper box and push "send" button.
• Received message shows in a lower box.

• Push "disconnect" button and exit.

• Run 9600 bps serial communicaion.
• Get a character and send it.

• http://thinkami.hatenablog.com/entry/2014/09/12/063140
• http://guminote.hatenablog.jp/entry/2015/08/13/193216
• https://hyperts.net/csharp-serial-wpf/