What do you do with 144 7-segment displays ... hand-coded lookup tables for each digit. The lookup tables are stored in ROM, saving precious RAM on the Arduino. A clock wouldn’t be any good ...

[Lewis] has just the thing for that: a big expandable 7-segment display. The build is modular, allowing it to be extended from 2 to 10 digits ... can be built using an Arduino Nano or an ESP8266 ...