I like that suggestion even more than mine :-)

Ehm, I don't recall, and I don't feel like opening up my cab right now. But I don't think it matters much. You will need to use a transistor able to supply current needed by your fan, which likely will be most of them. Have a look at this article for some more background.

@flop said in Fan GPIO and code control: If your fan makes much noise, you could change the GPIO voltage pin of 5v to 3.3v!. i dont think thats a good idea....fan draws too much current....