UAC audio intermittent.

SeenFan · ‎06-12-2023

Trying to develop a USB DAC application with RT1160.

Build project from SDK example:

evkmimxrt1160_dev_composite_hid_audio_unified_freertos_cm7

SDK version: 2.13.0
Test device:

- iPhone 13 Pro Max.

- iOS 16.4.1

- iPhone 12 mini.

- iOS 16.4.1

While connecting with iPhone. Run into a situation where audio playback become intermittent.
Reproduce steps:

Open the Apple Podcast app.
Connect the EVK. The audio will switch to the headphone jack output.
Open YouTube and play any video. The audio should be normal at this point.
Exit YouTube. The audio will stop. Wait for approximately 10 seconds.
Reopen Podcasts/YouTube/Spotify, etc. The audio may become intermittent.

Attaching a sniffer tool. I found that iPhone is always sending setInterface request after step4.

Control Groups:

- Yamaha AG-03
- Shure X2U

don't not have this issue.

kerryzhou · ‎06-30-2023

Hi @SeenFan ,

I have finished your 1KHz audio testing on my side, my wave is good:

My test method is:

Board USB J20 connect to the PC will emute USB AUDIO+HID DEMO interface.

1. Use window media player play your 1Khz

Then the board speaker will output the 1KHZ sound

2. Use the Audacity to record the sound from the PC mic, my surrounding is quite, so, it can record the board speaker sound, then I check the wave, totally OK.

You can see:

The original one and the record one are the same.

What's the code you are testing?

Use my previous project release version:

If you use the debug version to work, set the symbols NDEBUG.

I attach the new project again.

What's the product you want to use, if you also want to play in the PC and iphone for long time, do you mind to change to the Full speed instead of the High speed, then both PC and the iphone will stable, as my iphone 7 is full speed, no issues.

Best Regards,

Kerry

View solution in original post

SeenFan · ‎06-30-2023

Hi Kerry,

I don't see any difference right now. Attached my source FYI.

Regards

Seen

kerryzhou · ‎06-30-2023

Hi @SeenFan ,

If you still have issues, please test my new project which I share you right now:

https://community.nxp.com/pwmxy87654/attachments/pwmxy87654/imxrt/25757/1/evkmimxrt1160_dev_composit...

Any updated information, kindly let us know.

Best Regards,

Kerry

kerryzhou · ‎06-30-2023

Hi @SeenFan ,

So, your issue is resolved, right?

Please do more long time testing, if it is really resolved, please let me know, and our expert Tim Wang who help you do the deep research also very concerned your cases, do you mind also tell us, what's the product you are design?

Best Regards,

Kerry

Hui_Ma · ‎06-16-2023

Hi Seen,

We will do another test next week and update test result later.

Thanks for the patience.

best regards,

Mike

Hui_Ma · ‎06-13-2023

Hi,

I try to regenerate this issue with iphone, while looks like iphone could not recognize RT1160-EVK board as USB audio device.

I use a iMac PC works with RT1160-EVK board normally.

Could you show us how do you connect iphone with RT1160-EVK board?

If we need to install any APP to make USB device be recognized? Thanks.

best regards,

Mike