This project is dedicated to bring automatic presentation start and stop for the Raspberry Pi - should work on any linux machine, though. The detailed configuration applies mainly to the Raspbian (Debian Wheezy for Raspberry Pi) with the graphical user interface (LXDE).
DISCLAIMER: USE AT YOUR OWN RISK!
There was a need in my company to run a presentation easily and display them on a screen in the entry hall. As a Raspberry Pi is not really consuming a lot of electricity and thus it was an obvious choice. The following criteria were a requirement:
- Easy to use
- Display one presentation with at least one slide
- Needs to advance through the presentation (if more slides are available)
- when arriving at the end, it needs to restart
- cheap (free)
Then the obvious: use what you have...
- Raspberry Pi Model B
- no screen saver
- no blanking
- Samba Share (Windows Share)
- SSH connection for distance connection (The pi is in a different room than the screen)
The decision has been made, since okular is so smart that the advance and loop functionality can remain active even with only one slie in the presentation.Okular knows how to handle that. (true for nov 2017)
This should work on every Raspberry Pi running Raspbian Wheezy but it has been tested on a Raspberry Pi Model B and Raspberry Pi 2 Model B, as we have no others available at the time. Once Raspberry 3 Model B are in, tests will start.
The configuration is based upon a local installation. This means that you have a keyboard, mouse and a screen attached to be able to configure the pi directly. Additionally, you need a network connection.
This configuration also assumes that the Pi is in a virtual network or behind a firewall that does not allow connections from the outside of the network.
If your raspberry pi does not show full screen, it could be that the disable_overscan is commented out or set to 0. (Source 2018-01-10)
If you want to use the provided script as is, you should create a folder presentations in the root folder /home/pi/. Then you need to give it the permissions to be used by everyone chmod 777 presentations
it should be clear that the scripts and configuration can be adapted to your needs and requirements
Then you need to install the SSH server and the Samba server. Please consult the official documentation on how to install and configure them. And obviously, the presentations folder is the one to be shared in our example.
Create a file slide_time.txt in the presentations folder and edit it. It should only contain an integer value. That integer states the number of seconds each slide should be visible - we used 20.
The actual presentation should be called presentation.pdf and placed into the root of the shared folder.
The last 2 can be set at a later date - via windows share for example
Okular is a wonderful tool when it comes to PDF presentations. That allows us to have the automatic progression through and loop of the presentation. The python script will take care of the configuration of the SlidesAdvanceTime, SlidesAdvance and SlidesLoop settings.
Screen is used to be able to start scripts that run in the background, manually, so that you can disconnect from the pi without killing the script.
As the Raspberry Pi is, by default, blanking the screen after a set amount of time, we need to deactivate it. So start by installing xscreensaver, run it and disactivate the screen saver. Do not uninstall it afterwards as the blanking would come back. Additionally, you need to configure your .profile by adding the following lines at the end, if you desire to run the script via ssh:
export XAUTHORITY=/home/pi/.Xauthority
export DISPLAY=':0'This is needed to tell okular to which display to bind to as there is no default set.
Then you need to set the following in the file /etc/xdg/lxsession/LXDE/autostart to deactivate the screen blanking in X:
@xset s noblank
@xset s off
@xset -dpmsCopy the provided scripts, runner.py and afterstart.sh to the pi root directory /home/pi/. Remember that you can modify them as you please - it is under MIT license... But if you followed this tutorial, you should be able to just run them.
Now that you are set up, you can add a desktop background (like a company logo) and then power down the machine. Once powered down, you can move the pi to the final location, plug the network cable (for Windows share access) and HDMI in and let it run.
Once the system booted, you can connect to the Pi via SSH and run the scripts (copied in the the root directory).
The helper script afterboot.sh is killing the taskbar and running the python script using screen in detached mode. If you want to run just the python script without the removal of the taskbar, comment the line killall lxpanel (using a #).
It should run! You can now include the script in the auto start list. This should be done at your own risk. Because we want more control, we decided against it - we have to start it manually, each time we boot the machine.
Anyone having the username and password to access the share can change the presentation - unless you defined specific rights.
the presentation is relaunched automatically after one has copied a new presentation or modified the slide advance time. Additionally every operation might take a lot of time as we are talking about a Raspberry Pi.
If you delete the presentation.pdf or slide_time.txt the script will not die. It will stop the presentation or simply reset the time to the DEFAULT_SECS - found in the runner.py.
But all that has to be done by the user wanting to modify the presentation, is to connect to your windows share on the Raspberry Pi and copy the file. The rest is handled automatically.
If the presentation does not start, ever if you files are all in the correct place, please verify that the script is actually running. If you ran it using the provided afterstart.sh, then you can check simply by writing screen -r presentation. If nothing turns up, than consider rerunning the script or starting the command manually.