nRF5340 Audio DK: Audio Loosing sync both with I2S and U

[Nambiar]

Hi All,

       I have been using nRF5340 DK audio with toolchain Version 2.5.2 and using the Audio Demo (nrf5340_audio_dk_nrf5340_cpuapp_common) for gateway and headset (Broadcast source and Sink). I have not changed anything and used script to build and flash the binaries.

• The source and sink is able to manage sync only for ~10s in I2S case (Audio in at Source using I2S). 
• The source and sink is able to manage sync for ~ 1s in USB case.

This means audio plays for 10s/1s and then the sink is unable to get the audio afterwards.

As it is experimental SDK any suggestion to improve it or am I missing any configuration.

Regards

Sainath

[Nambiar]

Elfving : Any update , have attached the logs as requested.

[Elfving]

Great. Sorry about the delay from my side here, things are really busy these days.

So I heard that this can theoretically happen with the current Audio controller, as it prioritizes ISO over ACL. Though for it to be this bad your connection would really have to so suffering. Do you just have the two audio devices next to each other on a desk, or far away from each other? Is there anything close by that could interfere with the connection? If the DKs were wrapped in tin-foil it might explain this.

Regards,

Elfving

[Nambiar]

The BAP configuration of 48_4_1 or 48_4_2 is not explicitly mentioned in the KConfig of BAP  Module, any specific reason for it. Also from the spec it looks like the default BAP configuration is 48_4_2, am I right Elfving . Also Is there any way to get the exact number of BIS events or ISOC SDU packet received, any interface to get this information?

[Elfving]

I am not sure, so I just wanted to let you know that I've forwarded this question to the relevant R&D team. I'll let you know once I hear from them.

Regards,

Elfving

[Elfving]

Just heard back from them. For the broadcast we are not using the exact BAP configurations, but the closest thing is 48_4_1 (we reduce the number of retransmits). For the number of SDUs received you could change this to a LOG_WRN to get it printed every 1 second.

Regards,

Elfving

[Nambiar]

Thanks Elfving  for the information and code changes. I have few follow up questions.

• Is there a plan/way in code to support 48_2 at the receiver side. ( Table 6.5: Recommended LL parameters for broadcast Audio Stream configuration) in the BAP specifications pdf. This is required to evaluate the product level readiness in Wireless Interference scenario
• When will be the PTO config be enabled in BIS. 

[Nambiar]

Any update Elfving 

[Elfving]

Nambiar said:

• Is there a plan/way in code to support 48_2 at the receiver side. ( Table 6.5: Recommended LL parameters for broadcast Audio Stream configuration) in the BAP specifications pdf. This is required to evaluate the product level readiness in Wireless Interference scenario

48_2 is supported already, it's just a change of bitrate compared to 48_4

Nambiar said:

When will be the PTO config be enabled in BIS.

PTO is already enabled and supported for BIS. As long as max_transport_latency > 10 it should use PTO=1 (on the source side)

Regards,

Elfving

[Nambiar]

Great let me enable it and give it a try. Wanted to see the improvement on the SINK side. 

[Nambiar]

Hi Elfving , Thanks I was able to run the BIS configuration and hear the audio from another Gateway. Can you kindly give pointers to enable the same in Nordic Gateway . Also while recording the Sink through I2S , a lot of environment noise creeps in , is there a way to store the audio received in SD card or use USB as the audio out or some other mechanism to reduce noise on the Audio jack. 

[Sigurd Hellesvik]

Hi,

I am sorry for the delay, but Håkon is out of office this week.

I will look into this and let you know what I find soon.

[Maria Gilje]

Hi Sainath,

Thank you for your patience.

When building the nRF5340 Audio application after adding 

CONFIG_TRANSPORT_BIS=y
CONFIG_BT_BAP_BROADCAST_48_4_2=y

to my prj.conf and using the buildprog.py script to build and flash two nRF5340 Audio DKs with 

python <path_to_ncs-main>\nrf\applications\nrf5340_audio\tools\buildprog\buildprog.py -c both -d both -b debug -p -f

 the application behaves as expected.

Nambiar said:

is there a way to store the audio received in SD card or use USB as the audio out or some other mechanism to reduce noise on the Audio jack. 

The supported features for the nRF5340 Audio application are listed in nRF5340 Audio feature support and QDIDs. Output is only supported with I2S.

Nambiar said:

Also while recording the Sink through I2S , a lot of environment noise creeps in

I don't understand what you mean here. Please explain or elaborate what functionality you want.

Best regards,

Maria