He ended up designing an 8 by 16 grid of LED’s that was turned into a game of Tetris. He arranged all 128 LED’s into the grid on a piece of perfboard.

Our project is infact an Arduino with Serially Interfaced MAX7219 Operates an 8X8 LED Matrix to display a heart pattern. The MAX7219 IC is a serial input/output common-cathode display driver that ...

An Arduino drives the entire matrix with a single pin. Rather than reinvent the wheel, [Jack] used Adafruit’s NeoMatrix library to drive his display.