LED matrix is a great way to display things. Normally single matrix bloc is quite small. In order to get bigger picture you need to combine multiple modules. The best way is to use shift registers. Will built a modular LED matrix design that makes it easy to combine several 8×8 LED matrix blocks in to bigger one.
He used MAX7219 driver chips. They can be interfaced using SPI interfaces. And multiple chips can be daisy-chained. This setup requires few lines to control. Each module has convenient connector which allows quick plug-in many of them in a row.