A project were im using:
-8x8 bi color led matrix without PCB controller
-Arduino Timer interrupts
Material:
-1 Arduino(Nano or other, remember to change the pins used)
-1 decoder 3 to 8 negative logical
-1 decoder 3 to 8 positive logical(or negative logical + 8 NOTs)
-8x8 Led matrix
-8 1k Ohm resistors( 400 <-> 1000 Ohm )