using System;

using System.IO.Ports;

public class Program

{

    public static void Main()

    {

        SerialPort sp;

        sp= new SerialPort("COM3",115200,Parity.None,8);

        sp.Open();

        Console.Foreground=Console.Color.Green;

        Console.keyInfo k=Console.ReadKey();

        byte t;

        t= (Byte) k.[char];

        Byte[]tosend;

        tosend= new Byte[1];

        tosend[0]=t;

        sp.write(tosend,0,1);

        Byte r= ReadByte();

        Console.WriteLine("llego", + r.tostring());

        Console.ReadKey();

    }

}