# Embedded Motion Control 2012/FAQ

## Ubuntu

### I installed Ubuntu, but my wireless internet is not working.

You're wireless card is not supported by Ubuntu 10.04. One possible fix is to download the latest wireless drivers here, see Where to download bleeding edge. This page also contains detailed info on how to install the drivers. This basically boils down to:

1. Extract the tar ball into a folder
2. Open a terminal, and cd to the directory
3. Compile the driver against the kernel:
make
This may take a while.
4. Install the driver:
sudo make install
5. After a reboot, your wireless should be working.

Note: Since you build the driver against the kernel, you need to rebuild it after every kernel update, i.e., you have to again do the compilation and installation step described above.

### I try "svn co http://svn2.wtb.tue.nl/repos/emc2012/groups/emc01" but I need the GNOME keyring password.

Go to console [code]cd ~/.subversion nano config [/code]

Go to [auth] and enter below [auth] the following "password-stores =". Press ctrl+x and save the file with the same name (config). Open a new console and it works fine.

## RViz

### I've got an error with RViz and it doesn't start

If the error looks like this:

  The program 'rviz' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadDrawable (invalid Pixmap or Window parameter)'.
(Details: serial 22 error_code 9 request_code 136 minor_code 3)
(Note to programmers: normally, X errors are reported asynchronously;
that is, you will receive the error a while after causing it.
To debug your program, run it with the --sync command line
option to change this behavior. You can then get a meaningful
backtrace from your debugger if you break on the gdk_x_error() function.)
[rviz-6] process has died [pid 1978, exit code 1].


The following solutions can be tried:

In section 3.4 Segfault during startup from RViz troubleshooting page.

Open a terminal without Gazebo running and just type:

  export OGRE_RTT_MODE=Copy


If this does not work, just follow the next steps:

1 rosrun rviz rviz --sync ( add the --sync it even says in the error message)
2 don't give up even with sync it will fail,maybe...try it 2-3 times
3 if it still fails do rosmake rviz rviz and repeat step 1