I am using the pi as a switch to short the pins on my motherboard to turn on my computer. I see many people use an optoisolator to do this to protect the board. What purpose does the isolator serve as opposed to a transistor?
Can I hook the 5V power switch to the collector, and the emittor to the ground, then connect the 3.3V gpio out to the base? Wouldn't this protect the board and accomplish the task on the optoisolator?