Here is a simple, yet useful circuit of an Arduino 4-digit 7-segment LED display unit. The module used here is a self-contained, compact common-cathode module containing four 7-segment LED numeric ...

Check out the video below to learn more about the DIY Arduino laser engraver constructed using the innards from an old PC DVD player.

Being only ten at the time I was unable to build the thing and, now that I’m 40, I still can’t fathom how to build this DIY CNC plotter out of a DVD player and some Arduino gear.

There are so many nice hacks in [Joekutz]’s retro LED display project that it’s hard to know where to start. There’s his DIY LED display controlled by an Arduino UNO.