private void b_scan_Click(object sender, EventArgs e)
        {
            SerialPort port = new SerialPort(selectedport, 115200);
            port.Open();

            port.WriteLine("test");
            char[] macadress = new char[port.BytesToRead];

            for (int i = 0; i < macadress.Length;i++ )
            {
                port.Read(macadress, i, port.BytesToRead);
                    
            }

            string devices = new string(macadress);

            for (int i = 0; i < macadress.Length; i++)
            {
                terminal.AppendText(devices);
            }

            port.Close();
            
        }