this first installment will show you how to power your arduino from your computers power supply even when your computer is off.
and take control of the computers power switch using your arduino.
After this there are many different things you can do to activate your pc
Supplies you will need:
an arduino, any will do!
and jumper wires (two f-f and one f-m)
phillips head screw driver (to open your computer case)
Step 1: Powering the arduino
you will be tapping into the +5v standby pin on your computers power supply.
the easiest way to do this is simply to take the male end of your female to male jumper wire (or any wire) and stick it down the back of the connector and secure it there.
this is a constant 5v source when the pc is off and on.
then you just run that wire to the 5v pin on your arduino. dont use vin unless you have a 3.3v board (like my pro mini).
the ground can come from anywhere be it the 24 pin atx connector, a hard drive connector, or like what i did an unused usb header.
Step 2: The other connection.
unplug them both and connect your jumper wire to the ground on your arduino being powered by your computer.
touch the other end to one of the two pins. if the pc starts to shut down or power on (depending on which state its in) then thats the pin you need if not connect it to the other pin and connect it to adruino digital 13