The heart of the project is a MAX7219 4-in-1 LED display that costs well under $10. The board has four LED arrays resulting in a display of 8×32 LEDs. The MAX7219 takes a 16-bit data word over a 10 MHz serial bus, so programming is pretty easy.
The MAX chip can decode for seven-segment displays or just allow you to light up the outputs directly, which is what the code here does. You can cascade the chips, so it is possible to string more than one of these modules together.
The code is available on Dropbox. The code is extremely simple due to the use of the Parola library and a MAX72XX library. We’ve seen a number of projects based around this chip. Some of the uses are pretty novel.
Source: ARDUINO DRIVES A 600-CHARACTER DISPLAY
