Pillars of the Guardians

This is the code for controlling an interactive LED art installation which was built for Burning Seed 2019.

For more technical details, read this article.

Lights

Lighting is controlled by LX Studio. The code is in the lights/ directory.

Running the UI (requires Processing)

This is used for development. It will compile the code automatically.

$ bin/lights-ui

Load the lights/test.lxp project file to test the lights/wiring.

Load the lights/static.lxp project file to run a static light show with no interactivity.

Running headless

This is used for running on the Pi without a graphical environment.

You have to compile the code separately:

$ ant

Then run it:

$ bin/lights-headless

Controlling the lights

The LX Studio project is set up in a very specific way (see lights/Project.java). To produce various changes to the light show, there is a Python script at bin/lights-control. It sends OSC messages to LX.

To see usage information:

$ bin/lights-control --help

This script also plays sound files which are located in sounds/. They are no checked into the git repository, so you need to source them separately.

Sensors

Magnetic sensors are monitored via the Raspberry Pi’s GPIO. The code is in the sensors/ directory and is written in Ruby.

Testing sensors

This can only be done on the Pi:

$ bin/sensors-test

It will continuously print out which of the sensors are currently firing.

Running the sensor monitor

This can only be done on the Pi:

$ bin/sensors

Logging information is printed to stdout.

Developing the state logic

You can run the tests for the state management code off-Pi:

$ ruby sensors/pillar_circle_test.rb

The code in sensors/lights_listener.rb is where the sensor code talks to the bin/lights-control script, which then talks to LX.

Uploading to the Pi

When changes have been made, the Pi can be updated like so:

$ bin/upload [PI_IP_ADDRESS]

Configuring the Pi

There are various config files in config/. To install:

1. Copy them to the Pi with bin/upload
2. Run bin/configure-pi

This installs several systemd services. To enable and start them:

$ sudo systemctl enable lights.service sensors.service pulseaudio.service
$ sudo systemctl start lights.service sensors.service pulseaudio.service

To see logs:

$ sudo journalctl -f -u lights.service -u sensors.service

The Pi config in this repository is not currently exhaustive. There are some things that were done manually, such as installing dependencies.