SAPO DIGITAL SIGNAGE CLIENT
PROJECT STATUS (MAY 2ND 2014):
As such, we don't plan on developing this further except for bugfixes and "tactical" enhancements, since it's still very easy to use and deploy for relatively static displays.
UPDATE (OCT 1ST 2013):
Moebius is significantly smaller (it's aimed at embedded deployments) and assumes no desktop environment is installed (it doesn't even ship with X11), so it makes a lot more sense for digital signage.
SETTING UP FOR TESTING AND DEVELOPMENT
Clone the repo (no surprises here)
etc/config.json, making any required changes
STUFF YOU SHOULD BE AWARE OF
This is version 2.0 - version 1.0 was used internally at SAPO since October 2012, and 2.0 was deployed mid-2013 before we switched to a simpler video-only solution based on MEO Kanal also using Raspberry Pi hardware.
Here's a brief summary of the original requirements and their impact on solution design:
clients were not supposed to store any content locally, except a handful of templates to render baseline content. The idea here is that you'll be running this against a set of web services or a full web server that will render pages to the devices.
clients therefore run "playlists", i.e. JSON files listing URLs to render locally. Playlists can contain URLs to HTML content of various descriptions or to video files, and support time intervals and simple "random" groups.
the server can push new content to the client in near-realtime (depending on content type), including whole new playlists.
communication between client and server was downgraded from websockets to an HTTP(S) polling mechanism to better cope with firewalls, NAT, timeouts, etc.
accordingly, the client runs its own HTTP server to allow for disconnected operation (if the central server goes down, we'll always be able to display something, and cache some information in the meantime)
we had no idea what displays would be available, so we settled on 1280x720 as default and 1024x768 as a fallback. 1920x1080 is possible, but you'll be stretching the hardware to the limits when rendering HTML locally so it's not advisable (plus most people can't tell the difference when you're projecting or viewing from afar).
resolution is explicitely set on views to make it easier to size and position both HTML and SVG elements (the Codebits layouts were extensively based on inline SVG, with some dimensions computed inside views).
since we had to deal with both X and
omxplayer, resolution is assumed to be set in
/boot/config.txtas well as using
fbset(and even then we make sure
uzblis launched with the
geometryoption to clip the rendering surface)
Bring your image up to date and install required packages (some of these are only required for development and testing, but they add little to the overall footprint):
sudo apt-get update sudo apt-get dist-upgrade sudo apt-get install ack-grep bash-completion chkconfig denyhosts \ fbi git-core htop ntpdate omxplayer python-pygments tmux \ ttf-mscorefonts-installer unclutter uzbl vim watchdog x11-xserver-utils \ xinit xserver-xorg-video-fbturbo
moebius.configwill take you there if you choose
Internals) to set the framebuffer to 1280x720 by uncommenting these two lines:
# uncomment to force a console size. By default it will be display's size minus # overscan. framebuffer_width=1280 framebuffer_height=720
This will undo any automatic detection done during the boot process and significantly boost browser performance (full HD is nice, but it is also very slow without proper GPU support).
/boot/config.txt, set the GPU memory to 64MB to allow GPU video decoding to work:
# Set variable gpu_mem gpu_mem=64
/boot/cmdline.txtto disable the boot logo, move the boot VT to
tty9, disable the cursor and automatically blank the console:
dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty9 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait logo.nologo loglevel=3 quiet vt.global_cursor_default=0 vt.handoff=7 consoleblank=1
Setting up the client
Clone the repo to
/root(no surprises here):
cd /root git clone https://github.com/sapo/digital-signage-client.git cd digital-signage-client
etc/config.json, making any required changes
install/deploy.shto setup the configuration files and startup scripts
RECOMMENDED: Check the startup scripts and add corresponding video and image files for your splash screen (if any).
RECOMMENDED: use Hexxeh's rpi-update to upgrade to the latest firmware and kernel
sudo dpkg-reconfigure tzdataand choose your timezone
RECOMMENDED: enable the Raspberry Pi's hardware watchdog so that it will automatically reset the board upon freezing:
sudo modprobe bcm2708_wdog sudo sh -c "echo 'bcm2708_wdog' >> /etc/modules" sudo apt-get install watchdog chkconfig sudo sh -c "echo 'watchdog-device = /dev/watchdog' >> /etc/watchdog.conf" sudo chkconfig watchdog on sudo /etc/init.d/watchdog restart
Add the following lines to
/etc/default/rcSto disable swap and enable
Add the following lines to
tmpfs /tmp tmpfs nodev,nosuid,size=16M,mode=1777 0 0 tmpfs /var/log tmpfs nodev,nosuid,size=16M,mode=1777 0 0
The startup scripts assume you have four media assets in
boot.movis a 20s long, 12fps boot animation
down.movis a 20s long, 12fps shutdown animation
ready.movis an arbitrary "welcome" video
blank.pngis a 1280x720 PNG that acts as an "intermission" image
The 12fps framerate was chosen beause it yields <10MB files at 1280x720 resolution, and you can change the startup scripts to use static images instead.
Moebius differs from Raspbian in not providing a
pi user. Given that a signage client does not provide any services (even though it is physically exposed and thus essentially compromisable from the moment you deploy it), running everything as
root doesn't pose any significant extra risks and significantly simplifies matters.
However, the following are basic security precautions you should follow:
RECOMMENDED: change the
rootuser password (it's
raspiin the default Moebius setup, in case you're wondering).
sshdpassword authentication for the root login in
RECOMMENDED: Set up SSH access and add your public key to
/home/root/.ssh/authorized_keysfor remote maintenance.
sshdto run on another port (even with
denyhosts, it makes sense for some deployments) or block port 22 access from everywhere but the address(es) you'll be managing these from.
SD CARD IMAGES
Due to popular demand, I have to state that there are none publicly available yet. Still, if there were, they'd be sized for a 4GB SD card (purely out of cost considerations) and could be created by doing something like:
# a 4GB image has 3904897024 bytes, and we can write it via rdisk devices faster on OS X sudo dd of=/dev/rdisk2 if=~/Desktop/signage.raw.img bs=4m count=931
Note that the app has built-in support for diagnostics logging (which is kept in RAM and can be sent back to the server if so desired). This is set up as the
ram logger in
This can be very helpful in debugging the system remotely, but will not capture tracebacks as is (pull requests towards contributing that functionality are welcome).
The original blog post, wherein you'll find some screenshots of the server.
- This entire codebase is MIT licensed, and therefore free to use as you please for commercial or non-commercial purposes.
- Sample GIF images are CC Licensed from Wikimedia Commons.
- The Roboto Font is bundled as a convenience (and because it's eminently suited to digital signage) under the Apache License.
- The SAPO logo is a registered trademark of Portugal Telecom. It is included as a default part of this software's branding screen and cannot be reused for any other purpose.
As common courtesy, we ask you to preserve (and contribute to) source code comments, attributions and this
README if you decide to fork, deploy or otherwise redistribute this software.