There are already a ton of Instructables on Charlieplexing out there, so I won't go into the theory behind it, or how it works. This Instructable will instead focus on how I wired it up on my breadboard using 3 pairs of LEDs and 3 leads, then expanding it to 10 pairs of LEDs with 5 leads.
From a learning perspective, my objective was to learn about Charlieplexing. How does it work, and how do you code it.
Step 1: A Pair of LEDs
Wiring was going to be a mess, I figured, so I wanted my pairs of LEDs to be pretty compact. I put the LEDs in my breadboard facing opposite directions, in the same columns, practically touching, with a resister wired right next to them.