Does the I/O expander have a name and model or part number or where you bought it...
Little basic questions. Might you do us and yourself a favor and read this first? Please?
http://forum.arduino.cc/index.php?topic=149016.0
We All know what it says...
You didn't bother to read simple instructions that are written to help YOU in answering YOUR questions...
While it is obvious that your primary language isn't english that doesn't explain your refusal to try to understand the basics of asking for help on a subject that you've done little to understand yourself.
Therefore the answers you get might or might not be of any help..
Doc