I'm trying to learn how to charlieplex and I'm making a simple 3x3 matrix to try and learn how. My question is how do you control the matrix using Arduino? I have the LoL library but for something this small I'm not sure how to adapt it. Any help would be greatly appreciated!! Thanks!
You need to review your design & see what it takes to for highs & lows to make each individual LED turn on.
This may result in Off LEDs having high applied to both sides or low to both sides, or low their anode & high on their cathode ("reverse biased").
Start with 2 LEDs on 2 pins (remember the resistors on each pin),
Then 6 LEDs on 3 pins,
Then for 9 you extend this to 4 pins (normally 12 LEDs, so omit 3 of them...
If you want just 9 LED's you could just use 9 pins no need to get complex. The simplest way to get higher numbers is to use a shift register.