4,000-Pixel Animated LED Mural

Ben Sheffer, now an undergrad at MIT, has been interested in making LED displays since first hearing about them in middle school. While fascinating, the cost of creating such a display, not to mention actually writing the code and wiring it up, seemed daunting. Now, however, he’s decided to jump head first into this world, with a project consisting of 4,000 lights that are animated via stored bitmaps, or even algorithmically with external sensor input.

To handle the 40 x 100 matrix mounted on panels of plywood, Sheffer used a PIC32MZ0512EFE064 microcontroller, which he chose by looking up the fastest PIC/AVR MCU he could find for under $10. It runs at 252 MHz and has a floating point unit, giving it enough processing power for this massive job. To hook everything up, he designed a custom PCB to add the needed components and breakout GPIO pins for control.

Even with this custom board, wiring up 4,000 of these lights in RGB strips was no small task, requiring lots of wire, along with steel strips to hold everything together and act as power busses. He also added a plexiglass sheet overtop of the assembly to protect it in the lounge of his dorm.

At a final cost of $650, the price of the display isn’t insignificant, but he notes that it’s cheap as far as these things go. Be sure to check it out in the demo videos below of a dog running, as well as a rendered water reflection — more clips can be found in Sheffer’s write-up.