I've build an digital clock made out of 144 7 segment displays controlled by an arduino nano. The segments are controlled by 18 MAX7219 ic's which can control up to 64 individual leds or 8 7 segment displays. The array has 144 displays made each up of 8 individual leds so the array has an total off 1152 leds you can control.
(Note: when building this clock make sure the Tiny RTC’s headers are upside down so the battery faces downwards.)
Awesome project, ordered the boards and components soldered on all the bits except for the 7 segment displays, I have just placed a few on with the legs bent to test if any of the leds lit up, sadly none are lighting up, does anyone have any tips on debugging why they are not lighting up.