I’m looking for a way to use HA to switch between two audio RCA inputs. I found an automatic switcher, but the reviews concern me, so I figured HA can do it. One input will be a (dumb) TV and the other will be a Chromecast device, via an HDMI > RCA audio extractor. So, I can use the Chromecast state to trigger a relay. I’m hoping I can use an ESP8266 device tied to a 4ch relay like this. The RCA has a L+, L-, R+, and R-, so my thought is to use each channel of the relay to control each of those 4 wires. The output could attach to the middle common terminal, on input on the NC side and one on the NO side.
Does anyone have any thoughts on if this will work? It seems like it would, but I wonder if it will cause “noise” in the signal. Is there a better way to do this?
I had the chance to try this tonight and am happy to report that it appears to work well. The audio sounded as clear as it does without the relay in the middle.
Thinking about a manual switcher I had a long time ago, it only switched the signals and all the earth’s were permanently connected, this would mean only needing 2 relays for a stereo pair.
I connected the negatives for the connections on each relay. For example if you have left input 1, left input 2, left output all those negatives are connected together. Then right input 1, right input 2 and right output have their negatives connected to each other but not the left connections.
