I'm using an arduino 2560 because this model has more than 24 pins.
So it's not a hardware problem.
AS3Glue is an actionScript class (for Flash or Adobe AIR),
with this class Flash and Arduino can communicate together.
I am inspired by this tutorial for my projecthttp://www.kasperkamperman.com/blog/arduino/arduino-flash-communication-as3/
My project is a box with 20 buttons (my 20 inputs) and 4 lights (my 4 outputs)
when a button is pushed down arduino sends an order to my Adobe Air application
then the application shows a message on the screen (wrong) or (right).
If the message is right the Adobe Air application sends a message to the board which turns the light on.
I did a first test with one button and one light and it works fine
when I'm going over the pin 14 that don't work.
I'm going to try to connect firmata and processing to my arduino mega2560
in order to know if the problem isdue to firmata or as3glue.