Intelligent control of your receiver
It is annoying to manually control my subwoofer, which is located at the other end of the living room. To avoid this, you must implement your own “master / slave” circuit. First step is to detect when the receiver is turned on or off in a secure manner.
I can’t get this information via the receivers buildin network interface . It works only if the receivers is switched on.
A much more elegant way is a load depenting relay. I choosed the Eltako AR12DX-230V relais. The advantage is that it does not turn the receiver in standby but really only when a set load limit is exceeded. This relais is connected with an universal interface which sends the current state to openHAB.
The socket of the subwoofer itself is controlled by a switch actuators.
An additonal openHAB rule translates this states into on/off switch commands for the subwoofer socket.