HDMI ARC issues

[cr4zymanz0r]

NOTE: This is probably a hardware bug with the DE10-Nano. However, I believe this needs to be documented somewhere for the MiSTer community to see if others are having the issue and discuss if there is a possible resolution (even if it ends up requiring a hardware modification).

My Setup: So in my main setup my HDTV is connected to an audio receiver via HDMI which uses ARC (audio return channel) to pass audio from the TV to the receiver, as well as let me control the receiver for things such as adjusting the volume via the TV remote. This is a standard feature of HDMI since version 1.4 (if your TV and receiver support it).

The Issue: When the MiSTer (DE10-Nano) is connected to my TV and powered off, HDMI ARC does not function at all for anything. This means any audio from the TV or devices connected to the TV is not passed to the receiver, and the TV cannot control the receiver (adjust volume, power receiver off). Once the DE10-Nano is powered on, ARC will start working again but the behavior is sometimes inconsistent. Audio will start working, but sometimes the control functions (volume adjustment) won't work. Unplugging the HDMI cable from the DE10-Nano 'fixes' the problem.

Troubleshooting Performed: I removed all cables (even power) from the MiSTer except HDMI, and the issue was still present. I also removed the IO board and SDRAM board, but the issue was still present. I could plug the HDMI cable back in afterwards and audio on ARC would continue working, but once I power cycle the TV the issue would return if the HDMI cable is connected to the DE10-Nano. Enable DVI mode on MiSTer didn't seem to help either (which makes sense since the issue is present when the DE10-Nano is powered off). I tried different HDMI cables between the TV and receiver, and between the TV and MiSTer. It also behaved the same on multiple HDMI ports and even on a HDMI switch connected to the TV (even when the switch was powered off).

HDMI pin 14 is responsible for ARC. I've heard some devices can cause issues with ARC if pin 14 is connected to ground. I checked HDMI pin 14 on the DE10-Nano with a multi-meter and it doesn't appear to be connected to ground.

Anyone Else? Does anyone else have this issue with their DE10-Nano/MiSTer when connecting it to a HDTV that also has the TV connected to a receiver via HDMI with ARC? I realize connecting the MiSTer's HDMI directly to the receiver would probably be a work-around, but all the HDMI ports on my receiver are full (and some devices have to be directly connected to the receiver as the TV doesn't pass all surround sound formats to the receiver via ARC).

[jayp76]

The DE10-nano is not a consumer product, so it lacks some features. Keep in mind it is still a developer board. Maybe this fixable via software, but i doubt it. Or Hardware mod maybe? Don't know that.
Does the problem still occur if you connect the DE-10 nano to the AV receiver directly? I know it would be nice just to use one remote, but this might be a viable workaround for you.

[Freddo]

Had this exact same issue myself. Sorry I can't offer a more sophisticated fix but one of these adapters solved it:

https://www.amazon.co.uk/LINDY-HDMI-Les ... way&sr=8-3

[Sorgelig]

So, basically you can take any HDMI cable and with special tool precisely remove pin 13 and problem is solved.

[Locutus73]

Had this exact same issue myself. Sorry I can't offer a more sophisticated fix but one of these adapters solved it:

https://www.amazon.co.uk/LINDY-HDMI-Les ... way&sr=8-3

So, basically you can take any HDMI cable and with special tool precisely remove pin 13 and problem is solved.

I would have said pin 14 (ARC) more than 13 (CEC).
But maybe the CEC pin affects ARC too.

Regards.

Locutus73

[Sorgelig]

remove both then

[Freddo]

Another quick note, you'll likely find the same, this issue occurred literally any-way that I connected the MiSTer to my HDMI stuff. Via receiver or straight to TV either way my ARC would instantly break and never come back, even with the MiSTer powered off!

Once I added the adaptor to disable CEC (between the MiSTer and the TV) my ARC started working and I can even still ARC out the MiSTer audio to my receiver no worries.

Hope that helps.

[Will7046]

Had this same problem, I then hooked the de 10 nano up to a generic cheap manual HDMI switch box and it fixed the issue.

[spono]

Had this same problem, I then hooked the de 10 nano up to a generic cheap manual HDMI switch box and it fixed the issue.

I have the exact same issue. Mister hooked up to HDMI straight into the TV HDMI1, ARC from TV HDMI2 to receiver. If I hook the mister up to the TV, then ARC doesn't work. If I hook the mister directly up to the receiver, it doesn't pass video to the TV at all (not sure what that's about - maybe another issue with the Onkyo receiver entirely).

Which HDMI switch box worked for you? The Lindy Lindy 41232 HDMI CEC Less Adapter is ~$20 in the US and I'm looking for something cheaper.

I suppose I could just tear open an HDMI cable and cut the offending conductor...

[warham]

[quote="spono"][quote="Will7046"]not sure what that's about - maybe another issue with the Onkyo receiver entirely).

quote]


noticed my onkyo doesn't like a lot of resolutions. something to check if you get stumped.

[spono]

Well I fixed it by removing pin 13 from one end of an HDMI cable. Not too hard - just used a sewing needle to push the pin back, then tested all of the pins with a meter to make sure none were making contact with it. I also checked continuity on each conductor, and for possible continuity between pins adjacent to #13, just to be sure I didn't break anything in the process.

[reelbigeddy]

Having exactly the same issue at the moment. Thanks for documenting it so I know I'm not alone!

[Tacoguy125]

Thank you for documenting as I noticed these issues on hdmi cec devices after using my MiSTer. I'm Using HDMI CEC and ARC on a Panasonic TV and Onkyo receiver. Glad I can easily search this problem and potential solution.

[ExCyber]

The schematic shows a 0-ohm resistor and a Schottky diode (I think) connected to pin 13 of the HDMI connector, but those components are both marked "DNI" (do not install), so it seems like the CEC pin wasn't meant to connect to anything in the production version of the board. Maybe this could be fixed in a future manufacturing run without it being a new board revision, just by not populating those components when the board is assembled.