Hello guys,

a want to trigger and notify my phone if the door rings. I already open my intercom and found a 12v ac bell. Now i think its a option to use a diode to transform 12v ac to dc. After that i use a 12v to 3.3v stepdown board and connect this 3.3v line with the arduion interrupt pin.

Can this work the way I imagine? I am not quite as fit for electrical engineering. Or does someone know a finished solution in the form of a board to realize this?

The intercom is a SSS Siedle ht 611-01 w

Thanks :)