Sometimes you need to display a number nice and large, making it easily readable at a good distance. [Lewis] has just the thing for that: a big expandable 7-segment display. The build is modular, a… ...

The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52.