Jim Campbell: ToolsDemystifying “custom electronics”

Video camera

Monitor

FPGA

LED panel

Oscilloscope

Computer

Jim Campbell: Tools

Video cameraDigital video is captured in MiniDV format.

Signal is fed to custom electronics, where it is stored

for processing and playback

Monitor Simple video monitor used to preview video and select

areas to be represented with LEDs

Jim Campbell: Tools

FPGAField Programmable Gate Array

The heart of the “custom electronics,” these boards are similar to our own BASIC stamps

larger but more primitive; could be used to create a

BASIC stamp

Available off-the-shelf from Xilinix

Circuitry controlled by Hardware Description Language

Campbell uses Verilog to prototype and program

Verilog language similar to C, but easier

A concurrent language, it does not matter where a

line of code is in the program

Don’t have much memory; Campbell doesn’t need a lot for his video

Jim Campbell: Tools

LED screenUsually RGB, white or red light emitting diodes

Different colors produced from different

inorganic minerals

RGB just a combination of three individual diodes

Campbell first produced his own panels, now has panels produced

Jim Campbell: Tools

OscilloscopeCreates a two-dimensional graph of one or more electrical

potential differences (voltages, etc.) over time

Campbell uses oscilloscope for prototyping,

troubleshooting

ComputerProgramming FPGAs

Capturing raw video to be processed and stored by FPGA board

Jim Campbell: Basic Process

Video captured from computer

Sent to FPGA

Previewed on monitor

Pixels chosen

Stored on computer

Verilog used to program FPGA for LED screen playback

Jim Campbell: Alternates

In gallery, spare hardware and backups of all data are kept on hand

For outdoor lighting with lightbulbs, basic principles are the same, except using computer-controlled dimmers