Dan Conrad Chromaccord Performance Instrument

I developed the digital control system for Dan's Light Performance Instrument using an Arduino, code-generator, and custom PWM board.

The Chromaccord "smart controller" looks like a mixing board, but the sliders control RGB leds in the display. Dan has a number of "templates" that section off the display, so we have a mechanism to map the leds to the sections as he changes the templates. Dan then performs, by changing the colors in each section as experimental music is performed live. There is definitely a style to Dan's playing, in a psychedelic sort of way. A few other artists have performed with the Chromaccord, and do it differently. You can find some performances on youtube (look for "chromaccord" in the title) -- yes the afterimages and complementary color effects are intentional.

A mutual friend introduced me to Dan because I had been working on a LED control board, and Dan wanted a system that could control 45 sets of LEDs. The breakout board never made it into general production, but we used 3 of them in the Chromaccord, as well as the Arduino library I wrote (for the TCL59116).

I designed and implemented the software to read the 12 sliders, 3 selector switches, and map sets of LEDs to areas of the display. An essential part of the system was flexible mapping of LEDs to areas, and I included a code-generator in a Jupyter Notebook (also in the github link above). Dan designed and built the smart controller box, mounted, and wired the controls.

Dan already had a larger, analog version of this, but wanted something with more flexibility and more transportable. The original was RGB oriented (those sliders are in 4 sets of RGB), and so was this one, though I tried to convince him that HSV made more sense for the way he was thinking of the performance. Another artist did use the Chromaccord in HSV mode, and the later software for the Light Paintings evolved to use HSV.

Sadly, there have been few opportunities for Dan to perform with the Chromaccord since we built it. Please contact Dan if you are interested!

We anticipate using the Chromaccord to test patterns in Light Paintings, and we designed in the ability to plug the Chromaccord control system to the current Light Painting system (with a replaceable PWM object layer).

A big challenge in this project to was to allow Dan to create the "patches" controlled by the selector switches. He has a variety of templates that go in the Chromaccord, which require mapping the 45 leds into groups that match the template's geography. The code (data-structures) for describing that is very brittle (and annoying) in C++ (array of pointers to variable length arrays), so I used code-generation from python to C++. Jupyter Notebooks seemed like the best mechanism (documentation & code together!).