After months of (slow) development, the project is good enough for me to be used every day without hiccups, except a small software fix and another one in the enclosure that I'm printing right now. Will post updates soon.

I'd love this project being used by others too. But I realize it may not be that easy. First, because I published this project here on Hackaday.io only yesterday and I still have to figure out a lot of things. Second, the firmware itself needs a few tweaks to be customized for an environment that's not like mine. A few things right off the bat:

• When it starts, it looks for a MusicCast device called "Living Room" in the local network. Alas I couldn't tell to just pick up any device, because it uses "_spotify-connect._tcp.local" as a mDNS service name and many non-MusicCast devices may respond to that. You can change the device name in src/discovery.cpp.
• The firmware assumes the TV is an LG, with its remote control sending specific IR codes. If you have a different model, you should change the IR codes in src/config.h. Which codes do you need? Open the serial console after the upload and watch for "[IR:xxxxxxxx]" text every time you press a button.
• The minimum/maximum volume levels are hard-coded to 1 and 161, that's good for my Yamaha R-N602 amplifier. Yours may need different values. Again, they can be changed in src/config.h.
• The firmware supports Samsung Multiroom and Yamaha MusicCast protocols, but only one at a time and it's configured for MusicCast at the moment. In src/config.h you can change that.

That's all for now.