Mr Pacheko,
Not quite, I am sure there are several 3.3v RS485 interface chips available on the market (like the LTC1480) - you would need to have this interface chip between the Arduino pins and the DMX outside world. DMX works on a differential bus system and not 0-5v as you stated.
I have been using SN75176, which I believe will work at 3.3v but I havent tested it
Regards