Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable • Hacker News Board

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#121

Post by ssl-3 » Tue, Dec 16, 2025, 7:24 AM UTC

dontlaugh wrote: post #118

ssl-3 wrote: post #100

Earlier quoted context omitted.

The audio part can still be made to be simple. Others have mentioned toslink and I'd like to expand upon that. When you get a new TV and no longer have a headphone jack to plug your powered speakers into, then you can just add a DAC that converts the toslink digital audio that your new TV outputs into the bog-standard line-level analog audio that your speakers understand. DACs like this are available at all price poi…

But you’d be left without volume control, or at least from the same remote you control the TV with.

I've successfully set up sound bars with toslink and used the TV's remote to run the volume up and down. Toslink doesn't have to be a fixed level.

If future-TV lacks this functionality: DACs that have remote volume controls are very nearly as inexpensive as those that don't.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#122

Post by sandos » Tue, Dec 16, 2025, 8:24 AM UTC

I really need this in my life. Once upon a time, things were good and our Chromecast with Google TV knew _exactly_ how to turn on our soundbar, set our TV to output sound to said soundbar, control the volume on that soundbar using IR.

Now absolutely nothing of that works. The audio output on the TV is set seemingly semi-randomly depending on content!?. The volume controls just stopped working, and I can not FIND THE SETTINGS in the menus? I suspect it is required to completely redo the remote setup to see those settings, OR as I rather suspect: they broke this shit in purpose to get us to buy a new Google TV Streamer.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#123

Post by zimpenfish » Tue, Dec 16, 2025, 8:47 AM UTC

spacecrafter3d wrote: post #49

zimpenfish wrote: post #31

Earlier quoted context omitted.

Amusingly, my AppleTV is currently the one thing that doesn't even though it used to - for some reason, with no changes, it just stopped turning on the TV. Switch 2 can happily turn on the TV though. Most peculiar. (I've tried updating the AppleTV, replugging the HDMI cable, unplugging the HDMI cable for , etc. Nothing has worked. TV does not have any network which means it can't have had any nefarious updates.)

This has happened to me several times. I believe what fixes it is power cycling my AV receiver, in case it helps you.

Might if I had an AV receiver. Apple TV is plugged directly into the TV. But the TV does have a weird junction box (consolidates all the connections into a single cable up to the TV, maybe it counts as an AV receiver) and it might be worth unplugging everything from that and that from the TV. Will give it a try.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#124

Post by daoistmonk » Tue, Dec 16, 2025, 9:01 AM UTC

zimpenfish wrote: post #31

codepoet80 wrote: post #4

Yup, my AppleTV is the only device that gets CEC right. Even my LG TV and LG soundbar get confused. And don’t get me started on the PS4 Pro’s garbage implementation. I’m sad that Logitech killed Harmony because CEC was supposed to make universal remotes obsolete — they’re still the only way my full home theater can function without juggling a dozen remotes.

Amusingly, my AppleTV is currently the one thing that doesn't even though it used to - for some reason, with no changes, it just stopped turning on the TV. Switch 2 can happily turn on the TV though. Most peculiar. (I've tried updating the AppleTV, replugging the HDMI cable, unplugging the HDMI cable for , etc. Nothing has worked. TV does not have any network which means it can't have had any nefarious updates.)

try rebooting the remote: https://support.apple.com/en-us/102569 it always fixes problems with either turning the tv on/off or volume issues for me

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#125

Post by recursive » Tue, Dec 16, 2025, 9:04 AM UTC

ssl-3 wrote: post #100

recursive wrote: post #17

Modern AV stuff is insane. I have no interest in taking it up as a hobby. I have an xbox, a TV, and a pair of bookshelf speakers. How am I supposed to get the audio to the speakers without a bulky expensive receiver box? Luckily, I have one of the last remaining TVs with a headphone jack. I don't use a remote for any of it. Side note: Sometimes the TV doesn't come on when you press its power button. After a tremendou…

The audio part can still be made to be simple. Others have mentioned toslink and I'd like to expand upon that. When you get a new TV and no longer have a headphone jack to plug your powered speakers into, then you can just add a DAC that converts the toslink digital audio that your new TV outputs into the bog-standard line-level analog audio that your speakers understand. DACs like this are available at all price poi…

Thanks. Those are some helpful search terms.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#126

Post by InterlooperX » Tue, Dec 16, 2025, 9:31 AM UTC

Agreed that CEC is weird. Never thought about adding yet another device like the Pi into the mix to help control everything, though...

I have accepted that I am apparently in the minority with my setup. In fact I was actually surprised to read that OP has a Denon as, just by what I have read about the topic of home theater", everyone else seems to be doing just fine with a simple soundbar which has one! hdmi socket.

So, here is my setup: -Dumb TV (Panasonic. So old it doesn't have a CI+ module built in, it is "just" a CI module) -Denon AV Receiver -Nintendo Wii -Nintendo Switch Dock -Original Xbox -Blueray Player -HTPC -Satellite Receiver -AppleTV

Excessive? Maybe but I still own all that stuff, have room for it in my cabinet so I like to convenience of powering each of these on when I feel like it without having to unearth them from a storage room and then fiddle with cables to connect everything for just a short time of usage.

Basically everything is plugged into the Denon. And then a single HDMI cable goes from the Denon to the TV. So the TV stays on one HDMI channel and everything else happens on the Denon. Switch Inputs on there and you get the corresponding Audio/video signal from the chosen device.

So far I have been lucky that in order to switch everything on, I could use a Harmony One. I could simply program the power on command for the TV, then switch to HDMI1 and turn on the Satellite receiver. This was the default. Put it on a news station and you got yourself some background noise. If you want to switch, you just had to tell the Harmony to switch its input to any other device listed above.

It really irks me that the Harmony line is dead and I don't know what I will do should the remote, one day, stop to function. Now I wonder if I would have to go the Pi route to have that switch things around depending on devices announcing themself when turned on.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#127

Post by nottorp » Tue, Dec 16, 2025, 10:15 AM UTC

recursive wrote: post #17

Modern AV stuff is insane. I have no interest in taking it up as a hobby. I have an xbox, a TV, and a pair of bookshelf speakers. How am I supposed to get the audio to the speakers without a bulky expensive receiver box? Luckily, I have one of the last remaining TVs with a headphone jack. I don't use a remote for any of it. Side note: Sometimes the TV doesn't come on when you press its power button. After a tremendou…

I've solved the problem by slapping myself whenever I catch myself looking at sound bars, receivers etc for the living room.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#128

Post by redfloatplane » Tue, Dec 16, 2025, 12:04 PM UTC

ssl-3 wrote: post #100

recursive wrote: post #17

Modern AV stuff is insane. I have no interest in taking it up as a hobby. I have an xbox, a TV, and a pair of bookshelf speakers. How am I supposed to get the audio to the speakers without a bulky expensive receiver box? Luckily, I have one of the last remaining TVs with a headphone jack. I don't use a remote for any of it. Side note: Sometimes the TV doesn't come on when you press its power button. After a tremendou…

The audio part can still be made to be simple. Others have mentioned toslink and I'd like to expand upon that. When you get a new TV and no longer have a headphone jack to plug your powered speakers into, then you can just add a DAC that converts the toslink digital audio that your new TV outputs into the bog-standard line-level analog audio that your speakers understand. DACs like this are available at all price poi…

It's quite hard to know if the DAC is actually decent quality though. I've bought two from Amazon (admittedly at the low price point) and both of them have line noise - one of them even has a ground loop buzz, which surprised me, since it's powered by USB-C. I'm unconvinced that any of the higher price points (that are still within my budget) aren't just these cheapo ones in slightly fancier cases.

My old TV had real analogue out for speakers and it really did sound a lot better than what I've been getting through TOSLink and this cheapo DAC. Same Hi-Fi and speakers. I'm sure the problem could be solved with a more expensive DAC, but which one? How could I know?

I find this is one of those things where it's quite hard for the uninitiated to see through the cloud of 'audiophiles' saying that you must buy gold cables or your audio will sound like garbage, and still getting decent quality audio.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#129

Post by kimos » Tue, Dec 16, 2025, 12:48 PM UTC

I’ve tried getting CEC working with my pretty average setup: Samsung Frame, Marantz receiver, couple of console games.

It has been worse than doing all the remote juggling switching mysel because it is non-deterministic. This article will help me debug it, but it’s a toss up which audio device the screen will pick, if game mode activates or not, and if some device waking in the wrong order will put another one right back to sleep. Even if I follow the same steps every time.

Re: Fix HDMI-CEC weirdness with a Raspberry Pi and a $7 cable

#130

Post by k4rli » Tue, Dec 16, 2025, 1:23 PM UTC

recursive wrote: post #17

Modern AV stuff is insane. I have no interest in taking it up as a hobby. I have an xbox, a TV, and a pair of bookshelf speakers. How am I supposed to get the audio to the speakers without a bulky expensive receiver box? Luckily, I have one of the last remaining TVs with a headphone jack. I don't use a remote for any of it. Side note: Sometimes the TV doesn't come on when you press its power button. After a tremendou…

I've seen new cheap LG tv-s with horrible port selection while their premium OLEDs have everything necessary (except Displayport).

I had my LG C9 audio via the headphone jack going to amp and it worked fine. On one of the cheaper LGs I set it up similarly with optical cable and a tiny optical->rca converter.