Prerequisites

• Raspberry PI - but can be run on a local machine as well. This install guide was written using a new install of Raspbian Jessie (2017-04-10-raspbian-jessie.img). Make sure your system is up to date:

$ sudo apt-get update

• Python (http://www.python.org) - original code developed under python 2.7.10. Python should already be installed on your PI.

• Git (http://www.gitscm.org) - you will probably have the git command installed, but if not install it by:

$ sudo apt-get install git

• WiringPi (http://wiringpi.com) - original code developed against version 2.44. Currently the gpio command is used from this package. The code will first check to see if this command can be found before accessing GPIO pins. If the command is not present, a log message will be printed to the server output indicating so along with what pins were intended to be accessed. This allows for local development that is not happening on the PI.

To install WiringPi:

$ git clone git://git.drogon.net/wiringPi
$ cd wiringPi
$ git checkout -b 2.44 2.44
$ ./build

Verify WiringPi installed to the expected location:

$ test -e /usr/local/bin/gpio || echo "not installed"

If you see "not installed", check your WiringPi installation. If the installation was completed properly, you can delete the WiringPi repository

$ cd .. ; rm -rf wiringPi

Setup

Ensure this repo is cloned and cd into it:

$ git clone https://github.com/srqsoftware-hacknight/LEARN.git
$ cd LEARN

Running locally / for development

You can run the provided script to launch the HTTP server:

$ ./bin/run.sh

or invoke the CGI server directly. This command must be run in the project root directory:

$ python -m CGIHTTPServer

Open http://localhost:8000 in your browser. If you are accessing your PI remotely, you will need to replace "localhost" with the IP of your PI

Setup for kiosk mode on PI

Install chromium and utilities on the PI:

$ sudo apt-get install chromium-browser x11-xserver-utils unclutter

Update config files to support booting into "kiosk mode":

$ sed -i '/xscreensaver/d' $HOME/.config/lxsession/LXDE-pi/autostart
$ cat << EOF >> $HOME/.config/lxsession/LXDE-pi/autostart
@/home/pi/LEARN/bin/run.sh
@xset s off
@xset -dpms
@xset s noblank
@sed -i "s/\"exited_cleanly\": false/\"exited_cleanly\": true/" ~/.config/chromium/Default/Preferences
@chromium-browser --noerrdialogs --kiosk http://127.0.0.1:8000 --incognito
EOF
$ sudo reboot

Within a few seconds of the window manager loaded you should see the browser display the main page in full screen mode

Create a clickable Desktop application that will reboot the PI and reset to a good state:

$ cat << EOF >> $HOME/Desktop/LEARN.desktop
[Desktop Entry]
Name=LEARN
Type=Application
Comment=LEARN
Categories=Application
Exec=/usr/bin/sudo reboot
Terminal=false
StartupNotify=false
EOF
$ cd /usr/share/applications
$ sudo ln -s /home/pi/Desktop/LEARN.desktop

There is a shutdown.sh script located in the bin directory that will listen on a pin for a button press and execute a shutdown command.

This script can be added to /etc/rc.local by adding the following:

/home/pi/LEARN/bin/shutdown.sh &

Developing

The cgi-bin directory contains python scripts that get invoked. The controller.py file provides the main logic for determining which template to use and toggling GPIO pins. Given the small size of the functionality, its probably best to keep things here but feel free to refactor as needed.

The css directory contains CSS directives for the HTML files that live in the templates directory. To make changes to the UI, simply edit the appropriate CSS file or HTML template.

Edit the controller.py file if you are adding new functionality such as a new letter or button that renders a new page and so on. The index.html file serves as a convenience to automatically redirect requests made to the root URL to controller.py.

To change and re-generate the letter images:

./bin/generate-images.py /path/to/images/directory

NOTE: to use the image generation script you will need to have the Wand bindings installed:

pip install Wand