A 47×47 pixel array to display images and animations.
Design Objective
With this project, I wanted to build a large pixel array that could be used to show text, simple images, animations, and music visualizations. It needed to be big enough to be clearly seen from the street (for holiday decorations) and flat enough to hang on the wall as an art piece for the remainder of the year. It also needed to have an integrated power supply and control over wired or wireless networks.
Controller & Lights
To control this panel, I used my recently developed LED Controller. With this I paired 12mm bullet pixels, which are produced in strands of 50 and each have their own WS2811 chip inside, making them easy to address individually.
Structure
I targeted a final size of 4’x4′ so I could use a standard sheet of plywood for the backing. I designed a standard sub panel to hold 36 pixels in a 6×6 array, which would then itself be placed in a 6×6 tile configuration on the backing plane for a total of 1296 pixels. The panel was designed to be 200×200 mm, just small enough to fir on the bed of my 3D printer.
After making a few of these, I decided to pivot away from 3D printed panels. Printing 36 of these would have represented an investment of nearly 2.5 kg of filament, making an off-the-shelf solution a bit more viable. I found a machine-punched strip product that fit the problem perfectly and cost less than 2 rolls of PETG filament. It was also denser, with a 4’x4′ piece having 47×47-2209 total pixels.
Assembly was time-consuming, as I had to manually insert each pixel into its hole. I designed a tool to fit into the palm of my hand to make the process easier, but it still took the better part of 2 weeks of evenings to fill the entire grid.
Control Box
I found a 12V power supply to feed the array, and modeled a simple enclosure to hold it and the control board. I included a small hole to pass through the shaft of the control pot and vents to provide airflow to the power supply.
Conclusion
This project took much longer and was far more expected than I had originally assumed. The end result was large, extremely bright, and unwieldy to move and use. I will think twice before building something this scale again. Still, I am proud of the result, and learned a lot about scaling my projects in the process.
