This seems for me, like a difficult task, but maybe I am looking at the wrong ways to solve the problem.
I want a flat surface with multible lines of LEDs set up in groups of 9 in squares. I will try to fit between 30-50 groups on a certain space. (This is the final product, but i might just start with 5-6 groups)
Now, I want my phone to tell the first 9 LEDS, that LED number, 1-3-6 or something, should light up.
This will require alot of wiring, right? And the amount of pins on my Arduino will be few. I have read something about Charlieplexing, but the sites i have seen uses wiring.
Is it possible to create a curcuit or something similar to reduce the wiring? - and the space. I want it to be slim.