use mains AC as a switch for arduino?
February 13, 2013
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.
UPDATE: The chime's transfomer puts it at 16v AC. Also, there is a spare 4-cables-in-1 red wire that is live and unused as well.
UPDATE 2: Calculon knows to be careful, about disconnecting the power so he doesn't electrocute himself, and can live to a ripe old age and so forth. Thanks.