Random USB disconnection on android headunit.

[dd310]

Headunit is a DUDU7 (FYT platform - UIS7870 cpu - Android 13)

I started using HU Revived because of the limitations of the alternatives:

• Integrated CarLink app: Absence of any kind of settings, especially of DPI control -> interface is extremely zoomed in

• Autokit with CCPA dongle -> Awful UI, lack of two fingers gestures, need of bt connections even if only USB is beign used

I also like the availability of track info on media beign played in AA.

However, while using the same phone and cable I was using with these previous solutions, sometime the USB connection is randomly reset, causing AA restart.

I tries using all 3 USB ports (well, 2, as one is occupied by a USB DAC).

I'm attaching a log I saved right after one of these disconnections happened, but let me know if/how I can contribute debugging this behaviour.

https://pastebin.com/jqih7UKU

[teodortomas]

I'm getting random USB disconnections too (Not entirely sure what model and cpu I have, but i think it's a T100 platform). I just thought it was an issue with my head unit... maybe not?

Usually it recovers and reconnects, but sometimes I have to replug the cable.

I've had this issue from the very beginning of HURev, but I also noticed it before, when I was using HUR. That's the reason I thought it was a problem with my HU.

[dd310]

I tried to collect more logs today with debug logging enabled.

Two kind of disconnections occurred:

• The first @ 14:08, disconnection message appeared, had to replug the cable
• The 2nd @ 14:13, stream stopped and froze at the last frame, phone still believed it was connected (audio playback was not paused as it happened in the 1st case). Only after some minutes it timed out and disconnected.

I was thinking that maybe my headunit was cutting the usb link somehow, but using the same usb ports neither the original CarLink app, nor the CCPA dongle w/ AutoKit, nor the connected usb dac ever suffered from loss of connection.

I tried changing every setting in HU Revived, but none made a difference.
I even rooted my unit and deleted the integrated CarLink app, because I noticed that, even though autoconnect was disabled, it still had a service running in the background I thought it might be interfering. It did not help.

HUR_Log_20260619_140738_964.txt

[teodortomas]

I tried to collect more logs today with debug logging enabled.

Two kind of disconnections occurred:

• The first @ 14:08, disconnection message appeared, had to replug the cable
• The 2nd @ 14:13, stream stopped and froze at the last frame, phone still believed it was connected (audio playback was not paused as it happened in the 1st case). Only after some minutes it timed out and disconnected.

I was thinking that maybe my headunit was cutting the usb link somehow, but using the same usb ports neither the original CarLink app, nor the CCPA dongle w/ AutoKit, nor the connected usb dac ever suffered from loss of connection.

I tried changing every setting in HU Revived, but none made a difference. I even rooted my unit and deleted the integrated CarLink app, because I noticed that, even though autoconnect was disabled, it still had a service running in the background I thought it might be interfering. It did not help.

HUR_Log_20260619_140738_964.txt

Did you try software decoding?

[dd310]

I tried to collect more logs today with debug logging enabled.

Two kind of disconnections occurred:

• The first @ 14:08, disconnection message appeared, had to replug the cable
• The 2nd @ 14:13, stream stopped and froze at the last frame, phone still believed it was connected (audio playback was not paused as it happened in the 1st case). Only after some minutes it timed out and disconnected.

I was thinking that maybe my headunit was cutting the usb link somehow, but using the same usb ports neither the original CarLink app, nor the CCPA dongle w/ AutoKit, nor the connected usb dac ever suffered from loss of connection.

I tried changing every setting in HU Revived, but none made a difference. I even rooted my unit and deleted the integrated CarLink app, because I noticed that, even though autoconnect was disabled, it still had a service running in the background I thought it might be interfering. It did not help.

HUR_Log_20260619_140738_964.txt

Did you try software decoding?

I did not, but I tried both h265 (which was also artifacting, thus unusable) and h264

[andreknieriem]

I will take look at the logs and the code and see if I see somethings, that might break something ;)

[dd310]

Thanks!

[dd310]

Today I did a few more tests using a different and shorter USB cable, and the connections seemed to be stable.

I ran USB cables under the center console trim of the car, so it was a pretty long run overall (1m HU - CCPA / 3M CCPA - phone).
What i think might be happening may be a mix of different causes:

• The ccpa box was actively converting the signal, so the effective length was only the one ccpa - phone. Bypassing it increased the length -> signal degradation.

• HU revived might be less forgiving to data errors.

• Autokit and CCPA were using less bandwidth.

I'll continue testing in the nest days and will keep you posted

[andreknieriem]

Can you please try:
https://github.com/andreknieriem/headunit-revived/releases/tag/v.3.0.1-alpha

[dd310]

Tested this morning in two 30min drives:

• With the long usb run, issue persisted, stream froze randomly and only the last frame was shown.
• Using the short cable, the stream was fine and never froze.

I think I'll rewire my setup in the car trying to keep the usb run as short as possible.

[dima97rzd]

Hi. I’m still continuing to fight the same issue on my OnePlus 15. I previously wrote that this problem had generally been described as a widespread one here. But I recently read through some more forum threads, and it seems like it was supposedly fixed a while ago. Since those fixes, I have already received two updates.

I have already tried all kinds of things, such as disabling battery optimization, network optimization, clearing the cache, and so on — honestly, everything. But I also tried driving with Carlinkit, as someone suggested, and damn, it works stably. The only problem is that the functionality is absolutely terrible.

HUR_Log_20260621_210150_147.txt

During a short drive on version 3.0.0, I managed to reproduce this issue while recording the log. Could you please take a look? Maybe it will help clarify something.

I saw version 3.1.0, but when I installed it, with the same settings as in 3.0.0, the display was shown incorrectly on the screen. Black bars appeared at the top and bottom, and the touch input went crazy — or rather, when I tapped one icon, a different one was triggered.

[andreknieriem]

Yeah version 3.0.1 is not stable enough. Just testing and try to fix errors.

What I can see in your logs are 2 things.

1. You are using h265 (hevc) codec on a mediathek device. This codec has often bad implementation and can fail. I guess carlinkit just uses h264. Please try that too.
2. The log is full of usb read errors. And not less. Why carlinkit does not crash with that usb is strange. Should have worked bad too.
   I will take another look tomorrow to see, if I can find more errors.

[andreknieriem]

https://github.com/andreknieriem/headunit-revived/releases/tag/v.3.1.0-alpha here is a new version which introduced libusb as alternate usb driver. It can be enabled in the settings :)