I Have a remote that i took apart and i need to "press" the 6 buttons with my arduino.I have plenty of 2N3904 transistors (http://www.fairchildsemi.com/ds/2N/2N3904.pdf) could i use these instead of relays? The remote's power runs off a 12v battery.
Is there a question here?
To do it :- 1) connect the ground of your device to the ground of the arduino. 2) Connect the emitter of the transistor to the ground end of the push button. 3) Connect the collector to the other end. 4) Connect a 1K resistor to the base of the transistor and the other end to an arduino output pin.