Dennis Núñez-Fernández

BSc in Electronic Engineering, Universidad Nacional de Ingeniería (UNI)


Add basic graphical environment to Parallella Board

Demo video: https://www.youtube.com/watch?v=6gpM57qB-I8.

Requirements: Ubuntu PC and Parallella Board.

The following steps should be performed in Parallella Board.


Install LXDE

$ sudo apt-get install alsa-base alsa-utils libasound2-plugins lxde x11-xserver-utils xserver-xorg xserver-xorg-video-fbdev xserver-xorg-video-modesetting feh xinit


Disable PCManFM Desktop mode (for faster displaying)

$ sudo nano /etc/xdg/lxsession/LXDE/autostart

Delete the line @pcmanfm --desktop --profile LXDE and save.


Xorg configuration

Insert:

$ sudo nano /etc/X11/xorg.conf

The last command should show something like:

Section "Device" Identifier "Card0" Driver "modesetting" Option "ShadowFB" "True" Option "SWCursor" "True" Option "HWCursor" "False" EndSection Section "Screen" Identifier "Screen0" Device "Card0" SubSection "Display" #---- Uncomment your preferred mode ---- #Modes "1920x1200" #Modes "1920x1080" Modes "1280x720" #Modes "640x480" EndSubSection EndSection


ALSA configuration

$ nano ~/.asoundrc

Copy, paste and save:

pcm.!default { type rate slave { pcm "hw:0" rate 48000 } converter "samplerate" }

Then:

$ sync $ sudo reboot


Start X environment

On Ubuntu PC, connect to Parallella Board with (we add -X to enable remote execution of applications):

$ ssh -X parallella@192.168.1.110

And then enter the graphical environment:

$ startlxde

Note: Correct some problem "/usr/bin/xauth: file /home/technical/.Xauthority does not exist".

Exit from SSH and reconnect to SSH, this can solve this problem.

Note: Correct some problem "Error: X11 connection rejected because of wrong authentication", according to http://www.cyberciti.biz/faq/x11-connection-rejected-because-of-wrong-authentication/:

Make sure ~/.Xauthority owned by you.- Run following command to find ownweship:

$ ls -l ~/.Xauthority

Run chown and chmod to fix permission problems (replace user:group with your actual username and groupname):

$ chown user:group ~/.Xauthority $ chmod 0600 ~/.Xauthority

Make sure X11 SSHD Forwarding Enabled.- Make sure following line exists in sshd_config file:

$ grep X11Forwarding /etc/ssh/sshd_config

Sample output:

X11Forwarding yes


Install media player

Insert the command:

$ sudo apt-get install smplayer

Launch smplayer, then:

Options->Preferences->Video->Output driver: x11.

Options->Preferences->Audio->Output driver: alsa.

Note: If appear the next message "libqtgui4", solve with: http://answers.ros.org/question/203610/ubuntu-14042-unmet-dependencies-similar-for-14043/:

$ sudo apt-get install libgl1-mesa-dev-lts-utopic


Logout and exit from LXDE

To exit, logout and reconnect with SSH, or only Ctrl+C.


Result

Start with graphical environment:


Resources

- http://elinux.org/Parallella_Linaro_Nano#How_to_Install_lightweight_X_environment.

- http://www.cyberciti.biz/faq/x11-connection-rejected-because-of-wrong-authentication/.