I know very little about hardware hacking aside toying a little with Arduino.
There is a low voltage hook on the AC system that is specifically designed for this sort of use - although it will probably still require some sort of low voltage relay.
The room has been purpose built with remote control in mind so all of the lights etc have separate switches in a specially designed cupboard.
As for the HDMI-CEC, the only thing we really need it for is volume up/down on the sound bar. This is because the TV itself is a Sharp Aquos which has it's own remote control protocol that works over either IP or RS232 and can do power on/off and source changing. The TV's own CEC will control the sound bar volume with the TV's remote but errors when I try it using the IP/RS232 protocol – hence the need for separate HDMI-CEC. I've been diving into libcec which has now added native support for the RPi and it looks like sending volume up/down is relatively simple.
There is a low voltage hook on the AC system that is specifically designed for this sort of use - although it will probably still require some sort of low voltage relay.
The room has been purpose built with remote control in mind so all of the lights etc have separate switches in a specially designed cupboard.
As for the HDMI-CEC, the only thing we really need it for is volume up/down on the sound bar. This is because the TV itself is a Sharp Aquos which has it's own remote control protocol that works over either IP or RS232 and can do power on/off and source changing. The TV's own CEC will control the sound bar volume with the TV's remote but errors when I try it using the IP/RS232 protocol – hence the need for separate HDMI-CEC. I've been diving into libcec which has now added native support for the RPi and it looks like sending volume up/down is relatively simple.