How to connect to FG using interface UDP in C #

[fgjw]

Hi,
For some time I am trying to control the plane using the UDP interface in C#.

To do this, I run FlighGear with:

cd C:\Program Files\FlightGear 2020.3
SET FG_ROOT=C:\Program Files\FlightGear 2020.3\data
.\\bin\fgfs --aircraft=c172p --fdm=null --native-fdm=socket,in,30,127.0.0.1,5501,udp --native-ctrls=socket,out,30,127.0.0.1,5502,udp --fog-fastest --disable-clouds --start-date-lat=2022:05:09:09:00:00 --disable-sound --in-air --enable-freeze --airport=EPWA --runway=11 --altitude=00.0 --heading=0 --offset-distance=0 --offset-azimuth=0

In C #, I build a sample datagram and send it:


private int portHost = 5502;
private int portClient = 5501;

private string ipClient = "127.0.0.1";

byte[] buffer = new byte[409];

//version
buffer[0] = 0x00;
buffer[1] = 0x00;
buffer[2] = 0x00;
buffer[3] = 24;
//padding
buffer[4] = 0x00;
buffer[5] = 0x00;
buffer[6] = 0x00;
buffer[7] = 0x00;
//longitude
buffer[8] = 63;
buffer[9] = 215;
buffer[10] = 101;
buffer[11] = 206;
buffer[12] = 233;
buffer[13] = 115;
buffer[14] = 170;
buffer[15] = 144;
//latitude
buffer[16] = 63;
buffer[17] = 237;
buffer[18] = 35;
buffer[19] = 84;
buffer[20] = 102;
buffer[21] = 17;
buffer[22] = 94;
buffer[23] = 112;
//altitude
buffer[24] = 64;
buffer[25] = 90;
buffer[26] = 112;
buffer[27] = 0;
buffer[28] = 0;
buffer[29] = 0;
buffer[30] = 0;
buffer[31] = 0;
//agl
buffer[32] = 0;
buffer[33] = 0;
buffer[34] = 0;
buffer[35] = 0;
//phi
buffer[36] = 0;
buffer[37] = 0;
buffer[38] = 0;
buffer[39] = 0;
//theta
buffer[40] = 0;
buffer[41] = 0;
buffer[42] = 0;
buffer[43] = 0;
//psi
buffer[44] = 0;
buffer[45] = 0;
buffer[46] = 0;
buffer[47] = 0;
//alpha
buffer[48] = 0;
buffer[49] = 0;
buffer[50] = 0;
buffer[51] = 0;
//beta
buffer[52] = 0;
buffer[53] = 0;
buffer[54] = 0;
buffer[55] = 0;

buffer[56] = 0;
buffer[57] = 0;
buffer[58] = 0;
buffer[59] = 0;

buffer[60] = 0;
buffer[61] = 0;
buffer[62] = 0;
buffer[63] = 0;

buffer[64] = 0;
buffer[65] = 0;
buffer[66] = 0;
buffer[67] = 0;

buffer[68] = 0;
buffer[69] = 0;
buffer[70] = 0;
buffer[71] = 0;

buffer[72] = 0;
buffer[73] = 0;
buffer[74] = 0;
buffer[75] = 0;
buffer[76] = 0;
buffer[77] = 0;
buffer[78] = 0;
buffer[79] = 0;

buffer[80] = 0;
buffer[81] = 0;
buffer[82] = 0;
buffer[83] = 0;
buffer[84] = 0;
buffer[85] = 0;
buffer[86] = 0;
buffer[87] = 0;
buffer[88] = 0;
buffer[89] = 0;

buffer[90] = 0;
buffer[91] = 0;
buffer[92] = 0;
buffer[93] = 0;
buffer[94] = 0;
buffer[95] = 0;
buffer[96] = 0;
buffer[97] = 0;
buffer[98] = 0;
buffer[99] = 0;


for (int n = 0; n <= 308; n++) buffer[100 + n] = 0;


UdPClient1.Send(buffer, new System.Net.IPEndPoint(System.Net.IPAddress.Parse(ipClient), portClient));


The problem is that I don't see the effect. I get some data from FG.
Anyone where there may be a problem that I cannot change the location of the plane?



.

[erik]

Maybe it's this command line option which freezes flightgear:
--enable-freeze Start in a frozen state

You will have to turn of the freeze state afterwards to get any action from FlightGear.

Erik

[fgjw]

I would like to continue the topic because I have achieved positive results, but at this stage I have a problem with sending more parameters to FG. Communication works but only with setting two parameters. As I add the third is the plane jumps. The following sources cause that substituting data for pitch and altitude the plane is super moving. If I change the roll it breaks. Does anyone know what could be causing the problem?

MainWindows.xaml.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

using System.Windows.Threading; //DispatcherTimer
using System.Diagnostics;

using System.Runtime.InteropServices; //DllImport
using System.Threading;

using System.Net.Sockets;
using System.Net;

namespace FGCom
{
/// <summary>
/// Logika interakcji dla klasy MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
bool bfindFGFS = false;

DispatcherTimer dispatcherTimerPLAY = new DispatcherTimer();

int iCount = 0;

UdpClient client = new UdpClient();

public MainWindow()
{
InitializeComponent();
}

private void Window_Loaded(object sender, RoutedEventArgs e)
{
dispatcherTimerPLAY.Tick += new EventHandler(dispatcherTimerPLAY_Tick);
dispatcherTimerPLAY.Interval = new TimeSpan(0, 0, 0, 0, 100);

IPEndPoint ep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 49000);
client.Connect(ep);
}

float roll_deg = 0;

private void dispatcherTimerPLAY_Tick(object sender, EventArgs e)
{
iCount++;
lbl_count.Content = iCount.ToString();

// // Send the output to FlightGear
// //String sendString = X.altitude_ft + "," + X.latitude_deg + "," + X.longitude_deg + "," + X.roll_deg + "," + X.pitch_deg + "," + X.yaw_deg + "\n";

//String sendString = "100,37.613544,-122.357246," +roll_deg.ToString()+"0,0\n"; //; + 37.613544 + "," + -122.357246 + "," + 0.5f + "," + 0 + "," + 0 + "\n";

//String sendString = sld_alt.Value.ToString()+","+sld_roll.Value.ToString()+"\n"; //; + 37.613544 + "," + -122.357246 + "," + 0.5f + "," + 0 + "," + 0 + "\n";

String sendString = iCount.ToString()+ "," + sld_roll.Value.ToString() + ","+ sld_pitch.Value.ToString() +"\n";

Byte[] sendBytes = Encoding.ASCII.GetBytes(sendString);

client.Send(sendBytes, sendBytes.Length);
}

private void btn_start_Click(object sender, RoutedEventArgs e)
{
dispatcherTimerPLAY.Start();
}
}
}

MainWindows.xaml:
<Window x:Name="Window_FGCom" x:Class="FGCom.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:FGCom"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800" Loaded="Window_Loaded">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="91*"/>
<RowDefinition Height="328*"/>
</Grid.RowDefinitions>
<Button x:Name="btn_start" Content="START" HorizontalAlignment="Left" Margin="71,88,0,0" VerticalAlignment="Top" Width="75" Click="btn_start_Click" Grid.RowSpan="2"/>
<Label x:Name="lbl_count" Content="0" HorizontalAlignment="Left" Margin="190,88,0,0" VerticalAlignment="Top" Grid.RowSpan="2"/>
<Slider x:Name="sld_roll" HorizontalAlignment="Left" Margin="79,240,0,0" VerticalAlignment="Top" Width="666" Maximum="360" Grid.Row="1"/>
<Label Content="Roll:" HorizontalAlignment="Left" Margin="20,236,0,0" VerticalAlignment="Top" Grid.Row="1"/>
<Slider x:Name="sld_alt" HorizontalAlignment="Left" Margin="79,199,0,0" VerticalAlignment="Top" Width="666" Maximum="100" Grid.Row="1"/>
<Label Content="Altitude:" HorizontalAlignment="Left" Margin="20,195,0,0" VerticalAlignment="Top" Grid.Row="1"/>
<Slider x:Name="sld_pitch" HorizontalAlignment="Left" Margin="79,274,0,0" VerticalAlignment="Top" Width="666" Maximum="360" Grid.Row="1"/>
<Label Content="Pitch:" HorizontalAlignment="Left" Margin="20,270,0,0" VerticalAlignment="Top" Grid.Row="1"/>
</Grid>
</Window>

fg.bat:
cd "C:\\Program Files\\FlightGear 2020.3\\bin"
fgfs.exe --fdm=null --generic=socket,out,10,127.0.0.1,49001,udp,outputprotocol ^
--generic=socket,in,10,127.0.0.1,49000,udp,inputprotocol1 ^
--aircraft=c172p ^
--enable-hud ^
--units-meters ^
--altitude=stopy ^
--airport=EPWA
pause

inpuprotocol1.xml:
<?xml version="1.0" encoding="utf-8" ?>
<PropertyList>
<generic>
<input>
<line_separator>newline</line_separator>
<var_separator>,</var_separator>

<!-- Position -->
<chunk>
<name>altitude-ft</name>
<type>float</type>
<node>/position/altitude-ft</node>
<format>%f</format>
</chunk>

<!-- Orientation -->
<chunk>
<name>roll-deg</name>
<type>float</type>
<node>/orientation/roll-deg</node>
<format>%f</format>
</chunk>

<chunk>
<name>pitch-deg</name>
<type>float</type>
<node>/orientation/pitch-deg</node>
<format>%f</format>
</chunk>

</input>
</generic>
</PropertyList>

[wkitty42]

please put code in code tags as i've done in this quote...it really helps for readability and code alignment... also, you left out outputprotocol.xml

MainWindows.xaml.cs:

Code: Select all

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

using System.Windows.Threading; //DispatcherTimer
using System.Diagnostics;

using System.Runtime.InteropServices; //DllImport
using System.Threading;

using System.Net.Sockets;
using System.Net;

namespace FGCom
{
    /// <summary>
    /// Logika interakcji dla klasy MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        bool bfindFGFS = false;

        DispatcherTimer dispatcherTimerPLAY = new DispatcherTimer();

        int iCount = 0;

        UdpClient client = new UdpClient();

        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            dispatcherTimerPLAY.Tick += new EventHandler(dispatcherTimerPLAY_Tick);
            dispatcherTimerPLAY.Interval = new TimeSpan(0, 0, 0, 0, 100);

            IPEndPoint ep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 49000);
            client.Connect(ep);
        }

        float roll_deg = 0;

        private void dispatcherTimerPLAY_Tick(object sender, EventArgs e)
        {
            iCount++;
            lbl_count.Content = iCount.ToString();

            // // Send the output to FlightGear
            // //String sendString = X.altitude_ft + "," + X.latitude_deg + "," + X.longitude_deg + "," + X.roll_deg + "," + X.pitch_deg + "," + X.yaw_deg + "\n";

            //String sendString = "100,37.613544,-122.357246," +roll_deg.ToString()+"0,0\n";   //; + 37.613544 + "," + -122.357246 + "," + 0.5f + "," + 0 + "," + 0 + "\n";

            //String sendString = sld_alt.Value.ToString()+","+sld_roll.Value.ToString()+"\n";   //; + 37.613544 + "," + -122.357246 + "," + 0.5f + "," + 0 + "," + 0 + "\n";

            String sendString = iCount.ToString()+ "," + sld_roll.Value.ToString() + ","+ sld_pitch.Value.ToString() +"\n";

            Byte[] sendBytes = Encoding.ASCII.GetBytes(sendString);
                                         
            client.Send(sendBytes, sendBytes.Length);
        }

        private void btn_start_Click(object sender, RoutedEventArgs e)
        {
            dispatcherTimerPLAY.Start();
        }
    }
}

MainWindows.xaml:

Code: Select all

<Window x:Name="Window_FGCom" x:Class="FGCom.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:FGCom"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" Loaded="Window_Loaded">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="91*"/>
            <RowDefinition Height="328*"/>
        </Grid.RowDefinitions>
        <Button x:Name="btn_start" Content="START" HorizontalAlignment="Left" Margin="71,88,0,0" VerticalAlignment="Top" Width="75" Click="btn_start_Click" Grid.RowSpan="2"/>
        <Label x:Name="lbl_count" Content="0" HorizontalAlignment="Left" Margin="190,88,0,0" VerticalAlignment="Top" Grid.RowSpan="2"/>
        <Slider x:Name="sld_roll" HorizontalAlignment="Left" Margin="79,240,0,0" VerticalAlignment="Top" Width="666" Maximum="360" Grid.Row="1"/>
        <Label Content="Roll:" HorizontalAlignment="Left" Margin="20,236,0,0" VerticalAlignment="Top" Grid.Row="1"/>
        <Slider x:Name="sld_alt" HorizontalAlignment="Left" Margin="79,199,0,0" VerticalAlignment="Top" Width="666" Maximum="100" Grid.Row="1"/>
        <Label Content="Altitude:" HorizontalAlignment="Left" Margin="20,195,0,0" VerticalAlignment="Top" Grid.Row="1"/>
        <Slider x:Name="sld_pitch" HorizontalAlignment="Left" Margin="79,274,0,0" VerticalAlignment="Top" Width="666" Maximum="360" Grid.Row="1"/>
        <Label Content="Pitch:" HorizontalAlignment="Left" Margin="20,270,0,0" VerticalAlignment="Top" Grid.Row="1"/>
    </Grid>
</Window>

fg.bat:

Code: Select all

cd "C:\\Program Files\\FlightGear 2020.3\\bin"
fgfs.exe --fdm=null --generic=socket,out,10,127.0.0.1,49001,udp,outputprotocol ^
 --generic=socket,in,10,127.0.0.1,49000,udp,inputprotocol1 ^
 --aircraft=c172p ^
 --enable-hud ^
 --units-meters ^
 --altitude=stopy ^
 --airport=EPWA
pause

inpuprotocol1.xml:

Code: Select all

<?xml version="1.0" encoding="utf-8" ?>
<PropertyList>
  <generic>
    <input>
      <line_separator>newline</line_separator>
      <var_separator>,</var_separator>

      <!-- Position -->
      <chunk>
        <name>altitude-ft</name>
        <type>float</type>
        <node>/position/altitude-ft</node>
        <format>%f</format>
      </chunk>

      <!-- Orientation -->
      <chunk>
        <name>roll-deg</name>
        <type>float</type>
        <node>/orientation/roll-deg</node>
        <format>%f</format>
      </chunk>

      <chunk>
        <name>pitch-deg</name>
        <type>float</type>
        <node>/orientation/pitch-deg</node>
        <format>%f</format>
      </chunk>
 
    </input>
  </generic>
</PropertyList>

[fgjw]

wkitty42 thank you for your advice. Below I give source: outputprotocol.xml

Code: Select all

<?xml version="1.0" encoding="utf-8" ?>
<PropertyList>
  <generic>
    <output>
      <line_separator>newline</line_separator>
      <var_separator>,</var_separator>

      <chunk>
        <name>throttle</name>
        <type>float</type>
        <node>/controls/engines/engine/throttle</node>
        <format>%f</format>
      </chunk>

      <chunk>
        <name>elevator</name>
        <type>float</type>
        <node>/controls/flight/elevator</node>
        <format>%f</format>
      </chunk>

      <chunk>
        <name>aileron</name>
        <type>float</type>
        <node>/controls/flight/aileron</node>
        <format>%f</format>
      </chunk>

      <chunk>
        <name>rudder</name>
        <type>float</type>
        <node>/controls/flight/rudder</node>
        <format>%f</format>
      </chunk>
    </output>
  </generic>
</PropertyList>


wkitty42 do you know how to solve my above problem?

[wkitty42]

wkitty42 thank you for your advice.

you are welcome

wkitty42 do you know how to solve my above problem?

i do not, sorry...