I have connected analogRead(An) to a speaker that is driven by low voltage 0.5 - 1.5, that speaker is just a "standard" home interphone system which "rings" when you press the interphone bell. I am aware that I cannot continously read that voltage because it is AC. I cannot use bridge rectifier be…

Reading "ac voltage pressence" using software only.

jremington May 28, 2018, 4:04pm 12

This will not be long term solution.

Guaranteed!