BulletMagnet83:
You should be able to do it using only three pins, plus power/ground with the right driver chip! So no need for I/O expanders unless you really want them.www.youtube.com/watch?v=ND7777N1h8Q
An example I built using the MAX7219 driver. Only works with common cathode displays though, so if you have common anode you'd need something else... but it was pretty easy to get running and I'm hardly an expert user!
Great work.
I also want to be able to control those 5 digit leds dynamically with a data feed coming to the arduino board from a computer (for example : led no 3 = 25345 or led no 1 = 00293) so that's another weird part.