use mains AC as a switch for arduino?
hey gang, does anyone know if it's possible to use mains AC as a switch for the 'duino?
A little background:
Calculon is working on a project that he hopes will take advantage of his doorbell's AC power. He wants the old-school analog doorbell switch to activate a function on his arduino instead of firing off a solenoid in the door chime. Is this possible with some sort of voltage divider? He doesn't need to measure the current, voltage, phase, or anything liek that, he just needs to sense on/off like a pushbutton. He assumes the initial doorbell voltage will be 120V.
[original story: Let's Make Robots]