The TV-B-Gone is a well known piece of kit in hacker circles: just point it at a noisy TV in a public space, hit the button, and one of the hundreds of IR remote codes for “Power Off” that it ...

The first step was to enable communication between an Arduino Micro and a Nokia cell ... [Lauters] then took the phone apart and tapped into the power button to control on/off states.

You can read the state of a button using Arduino and a few lines of code ... you want to and you can even add extra circuitry to turn ON an LED or use a relay to power up different equipments.