Pictures

• Finished project.
• Finished project.
• Finished project.
• Finished project.
• Me testing the control circuit.
• Dima testing an LED.
• Wiring an LED.

Scope

• Lines of code: 6605 C++, 214 Java, 400 assembly.
• 169 tricolor RGB LEDs. 676 total solder joints on the net.
• Feet of wire: 3000
• Personal hours of work: 250
• Total hours of work: 1000
• LED power consumption: 20 watts
• Number of ICs: 37
• Cost: $800

Design

The three major parts of the system are the LED net itself, the control box, and the computer. The LED net is logically arranged into 12 rows and 48 columns. Since each LED is really three LEDs, this arrangement allows for 192 LEDs. The LED net is a regular hexagon with 8 LEDs on each side spaced 12 inches apart. The large hexagon is essentially filled with smaller 12 inch hexagons to create a repeating hexagonal pattern. This arrangement requires 169 LEDs.

Controlling each LED individually would require 507 outputs from the control circuit to the LED. This is clearly unrealistic. Instead, the circuit has an output for each row and each column. The controller quickly cycles through each row turning only some of the columns on within that row. By cycling at around 100Hz this is not apparent to a viewer but only 60 outputs are required.

The control box uses a USB interface chip to download new patters from the computer in real time. It then stores the new pattern in RAM while simultaneously cycling through LEDs. by controlling the duty cycle of each LED it can control the apparent brightness.

The Computer software generates patterns based on user input through a Java program (the actual computation is done using CC++) and the input to the computer's sound card. This lets us make the LED net operate in sync with the music.

Credits

• Joe Olivier developed the concept and helped design and write the software.
• Dima Kernasovskiy much of the physical construction of the LED net.

• Software engineering: Spensor Rarrick, Jessica Gray, Dough Hanley, Alan Somers.
• Mechanical design and construction: Laura Rogers, Mary Ollenburger.
• Other engineering: Joshua Goldstein, Thomas Quetchenbach, Daniel O'Hanlon, Peter Foley.
• LED net construction: Vera Pavel, Jenny Iofinova, Ross Losheri, Jeremy Ehrhardt Alan Rubink, Valerie Syverson, Jacob Leonard King.
• Putting up with me: Adam Azarchs
• Having a USB host controller that doesn't suck: Advanced Micro Devices.
• But David! I worked on the LED not and I don't see MY name on your list. I'm a busy man and I know I've forgotten a lot of people who helped. Tell me who you are and which list you want to be on and I'll add you.