Discussions

I have ArduPilot Mega Software-In-The-Loop almost working in 64-bit Ubuntu 12.04. Only problem is that there seems to be a lack of MAVLink packet communication. Can anyone help me out?

Following is how I set up the simulation software. I hope this will serve as a tutorial once I get past that final problem.

1. Open a terminal console window.
2. Make a new folder for simulation software and enter the directory:

   mkdir sitl
   cd sitl

3. Install prerequisites, if missing:

   sudo apt-get install git python-serial g++ autoconf libtool automake gawk

4. Download MAVProxy, mavlink, JSBSim and APM:

   git clone git://github.com/tridge/MAVProxy.git
   git clone git://github.com/tridge/mavlink.git
   git clone git://github.com/tridge/jsbsim.git
   git clone https://code.google.com/p/ardupilot-mega/

5. Build and install JSBSim:

   cd jsbsim
   ./autogen.sh
   ./configure --enable-libraries --enable-shared --prefix=/opt/jsbsim
   make
   sudo make install
   cd ..

6. Build ArduPlane and ArduCopter binaries and copy them from temporary folder:

   cd ardupilot-mega/ArduPlane
   make -f ../libraries/Desktop/Makefile.desktop
   cd ../..
   cp /tmp/ArduPlane.build/ArduPlane.elf .
   cd ardupilot-mega/ArduCopter
   make -f ../libraries/Desktop/Makefile.desktop
   cd ../..
   cp /tmp/ArduCopter.build/ArduPlane.elf .

7. Install flightgear:

   sudo apt-get install flightgear

Now, because JSBSim did not install it's binaries in the system folders when I ran "make install", I have to make sure that the binaries can be found by simulation scripts. As a temporary hack, I added the following folder to the $PATH variable: "~/sitl/uav/sitl/jsbsim/src". This is where the compiled but uninstalled JSBSim executable is located.

I tried to run the simulation, following this tutorial. Opening four separate terminal tabs, I launched these executables, in order.

1. First terminal:

   cd sitl/ardupilot-mega/Tools/autotest
   ./fg_plane_view.sh

2. Second:

   cd sitl
   ./ArduPlane.elf

3. Third:

   cd sitl/MAVProxy
   ./mavproxy.py --master tcp:127.0.0.1:5760 --sitl 127.0.0.1:5501

4. Fourth:

   cd sitl/ardupilot-mega/Tools/autotest/jsbsim
   ./runsim.py --home=-35.362938,149.165085,584,270 --script=jsbsim/rascal_test.xml --fgout=127.0.0.1:5503

Note that if you execute "./fg_plane_view.sh" last, then FlightGear gets stuck at loading scenery.

This is where I ran into problems. The simulation is not moving. In addition, I discovered that the MAVProxy output is too clean -- it has only ASCII text, no binary MAVLink data. The expected output is described here.

What am I missing?

Edit: It seems that things are working. If I type "auto" into the MAVProxy, as Daniel suggested, the plane starts to fly (and crashes into ground in a minute or two). Still, I see no binary data in MAVProxy output, but this may be a feature.