I am a newbie to Arduino, and I really am not sure how Arduino works. I am trying to create a relay that can be triggered by line level audio. When audio is sent to the relay I want the relay to close, and output 12 volts dc. The 12 volts of dc is to trigger on an ac outlet. What Arduino do I need? How do I hook it up? Any information can help. There would have to be some type of timing delay adjustment so if audio dropped out for 5 to 30 seconds the relay would not ope. Also a sensitivity threshold adjustment for how much, or little line level audio will trigger the relay. I am at the very beginning starting point with all of this. Keep it simple if you can. Thanks for any help you can give me.
Look for audio trigger modules for Arduino, and for relay modules. Both have to be added to a bare Arduino. The modules should come with data sheets and example code. Even the smallest Arduino will do what you want.
I want the relay to close, and output 12 volts dc. The 12 volts of dc is to trigger on an ac outlet.
That doesn't make complete sense to me.
Sounds to me (pardon the pun, being an audio project haha) that you just need a relay module as DrDiettrich said. The Arduino output will trigger the relay; the mains AC live will be broken and attached to the relay's Normally Open (NO) and Common (COM) outputs. When the relay is energised, the outputs will connect and the power to your load will be established.
(That means of course that the outlet will need to be on all the time....)
You might consider one of these.
So you want something on (or off) when the audio is (mostly) present.
If that “ac voltage” is 110v (US) or 240 (uk and others)… be very VERY careful here.
The audio: Is it already “in a wire”, as a voltage, or is it still just in the air?
If not already in a wire: