Here is a simple, yet useful circuit of an Arduino 4-digit 7-segment LED ... Also, this multiplexing technique turns the massive amount of microcontroller pins ... /* * Arduino 4x7 LED Display * ...

What do you do with 144 7-segment displays? If you’re [Frugha] you put them all together to create an epic clock. Each display has 8 individual LEDs — 7 segments, and a decimal point. P… ...

“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 ...