Hi everyone! My name is Courtney Allen and I am a Graduate Research Assistant on the DILAC Lab Floor Chart project at Georgia Tech. This large-scale LED project is a modernization of the work developed by Elizabeth Palmer Peabody. She was an early innovator in data visualization and she promoted a method involving a large chart on the floor that students sat around and discussed. The original chart was a giant 30×30 grid of squares divided into nine equal subsections; the objective was to map the squares to major history events within a century’s time. Sometimes, the students were asked to color in the squares themselves. For a more in-depth description of Peabody’s work, please visit shapeofhistory.net, the predecessor of the Floor Chart project, shown in figure 1. You can also read the abstract from the project team’s presentation at Digital Humanities 2018, which I co-authored with the 2017-18 members of the project team.
The Floor Chart project is directed by Prof. Lauren Klein, and is part of her larger interest in the history of data visualization, as well as her work on data feminism. In short, the project proposes that Peabody’s unconventional visualization scheme poses a feminist alternative to standard visualization techniques. It’s interactive, it involves the whole body, and it allows the viewers of the visualization—who were students themselves—to create their own knowledge about the past rather than simply receive someone else’s story.
While the project thinks through issues of power and knowledge, much of my work involves thinking through issues of power of another kind. Currently, the Floor Chart project is attempting to power on the massive grid of 900 LEDs without short circuiting. In order to successfully achieve this, I am investigating how to either (1) break up the power source into 6 sources use each to power a section of 5 LED strips; or (2) find a power source with enough amperes to power all of the LEDs together. There are advantages and disadvantages to both options.
If the project is powered by multiple power sources, the advantage would be our ability to diagnose subsections of the LED strips with more accuracy should anything go wrong; however, the disadvantages are that it creates a physical larger circuit to complete – meaning there are more potential areas for wires to disconnect or for the circuit to go awry – and that there are multiple plugs needed to power so many power sources.
If the project is powered with one single, large source of power, the advantages are that the circuit is smaller, so that there are fewer potential areas for the wires or circuit to go awry, and that there is only one power source to deal with. However, the downsides with the large power source are that if something should go awry, the outcome is riskier, as more amperage is involved, and also that problem areas will be harder to define and diagnose.
Since the first option is the safer one, we decided to scale down to 5 strips to better understand how a scaled power source setup would work. As seen in figure 2 and 3, we were successful in having the arduinos connected to the LEDs at this scale. Our next step is to prototype a more permanent, modular setup that could work for the small-scale version and proceed with multiple power sources, or begin to think through the safety involved in a setup involving a single power source.
Hopefully nothing will blow up and next time you’ll hear about many LEDS being turned on at the same time!