Quote Originally Posted by manumenzella View Post
Hey. Thanks for all the answers. I think im going to connect a npn transistor as most of you suggested. The probem is that, as it is battery powered, i need to keep the current draw very small. Do you know which will be (more or less) the current flowing from the IO to the base of the npn???
I was going to use the multimeter to measure it, but, after the cleaning lady came home, the screen was broken into pieces!!!
Well, thanks again for your help
Manuel
Using a transistor instead of a MOSFET is going to cost you a few mA in base current right there. MOSFET's have practically no gate current, generally in the pico-amps (except when switching states due to gate capacitance). Use an N channel MOSFET, 2N7000. It'll easily handle 12v across the drain-source, and switch on/off with 5v logic levels on the gate.