Hi,
I have a home smart doorbell/intercom system, which is powered by 12 V/AC and connected to the chime. the intercom system has only 2 wires - it doesn't have separate wires for push button and power.
What I want to do is to detect an "intercom button" press with the Moteino.
I've measured voltage on the circuit and there is about 3.9Vac when intercom is in stand by, and once you push the button, it spikes up to 12Vac.
Any idea how to detect push button event with Moteino?
I was thinking about using an AC relay or something, which will be triggered by that 12Vac spike. I can detect closed relay switch with Moteino then ...
Will that work or is there any simpler solution? If using relay is the way to go, then which relay is appropriate for this job... DC relays probably can't be triggered by AC?