The MAX7219 is one of those parts in your bin that has a “done and done” attitude. In case you’re unfamiliar, this chip can be used to control 7-Segment displays, 8×8 Matrix displays ...

What do you do with 144 7-segment ... with a single Arduino Nano. Even charlieplexing won’t get you that many I/O lines. The solution was a nifty little chip called the MAX7219.

“I’ve built a digital clock made out of 144 seven-segment displays controlled by an Arduino Nano. The segments are controlled by 18 MAX7219 ICs which can control up to 64 individual LEDs or 8 ...