The 7-segment displays are excellent for numerical data, while the 14-segment displays can handle both numbers and letters, making them suitable for more complex information displays.

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.

Reddit user Krukerfluk has created an awesome DIY digital clock using 144 x seven segment displays, combining them to create a larger LED display powered by an Arduino Nano.

The LEDs are arranged onto 100x100mm boards that each contain an Arduino Nano and 9 seven segment displays, daisy chained through three-pin headers located on the sides of the boards.