nRF5340 Audio - configure gateway unit also as ACL peripheral

[Dekel]

Hi,

I'm working with nRF5340 Audio DKs.

I'm able to successfully run the audio example in BIS mode (with gateway and headset devices).

My goal is to open another BT connection, in parallel to the audio broadcast on my gateway device, to which I can connect with the headset units and the nRF Toolbox App via NUS. I'd like the gateway device to act as peripheral in that manner and to be able to connect to 6 different devices concurrently via NUS (5 headset units + 1 smartphone app).

I tried implementing it by myself, and I feel like on the brink of it, but calling bt_le_ext_adv_create() twice (once for audio and once for ACL) fails with EIO (I/O error). It's unclear to me why it happens. As I see it, the challange is to create 2 concurrent advertisements in the gateway unit - audio streaming and ACL connection.

On this ticket I received great help from Brian Kim, which implemented the gateway device as central in terms of ACL connection.

I'll share that I was able to deduce from his development and successfully configure the headset device as central in terms of ACL connection (in parallel to audio streaming receival). here are the relevant files: headset_as_ACL_central.rar

I would appreciate any help with such implementation.

Thank you,

Dekel

[Brian Kim]

Thanks for your patience, Dekel.

Please the attached file. As you know, adding ACL link affects the LE audio performance directly. so you can tune the related parameters number of retransmissions, bitrate, advertising interval and so on. For better performance, you should tune the numbers accordingly. 

  

Best regards,

BrianModifiedFiles.7z

[Dekel]

Hi Brian,

I tried to run the code you've shared as it is. When trying to connect to the gateway unit with my iPhone, either through nRF connect for mobile or nRF Toolbox, it doesn't succeed.

I receive the error of BT_HCI_ERR_CONN_FAIL_TO_ESTAB and the unit constantly connects and disconnects from the iPhone:

I'll mention that there's no I2S audio source connected to the gateway unit and also there's no headset unit around it. That's in order to avoid interference.

I tried to manipulate prj.conf, but with no success.

I would appreciate your help.

Thanks,

Dekel

[PassionPioneer]

As a part of deleting the bonding information I followed following steps

1. Disable scanning on smartphone and advertising on the audio dk
2. Re-enable scanning on smartphone and advertising on the audio dk

But there is no change in the behavior. 

Thanks for looking to this.

Regards,

Naveen

[PassionPioneer]

Hi Brain,

Is there any update?

Regards,

Naveen

[Dekel]

PassionPioneer said:

I am working on same type of requirement in nRF5340 audio DK, I replaced files and tested with smartphone with android version 12. The board is connected and able to receive the data sent from the mobile but after few seconds the board is getting disconnected. The following is the error log image, please suggest the solution

Hi Naveen.

the security warning got my attention, I believe it's worth looking into that.

Please look in bt_mgmt.c - is bt_conn_set_security() being called? (it should appear once in that file). In my code it's commented-out.

[Brian Kim]

Hello Naveen,

I tried with the binary I shared before(merged_domains_BK.hex) and confirmed it works without any issues with my pad(not Redmi).

-. Does the issue happen only on the specific device(Redmi Note 9 pro)? what about with the other devices?

-. Are you testing with the same binary?

//Brian

[PassionPioneer]

Hi Dekel ,

Thanks for your suggestion, it worked. Now I don't see any connection lose. 

Now I will check communication from peripheral to central.

Dekel, please do provide any more suggestion you would like to provide as I am needed to make work audio and sensor data together on single chip.

Regards,

Naveen.

[Brian Kim]

Hello Naveen,

Thanks for the good news. Please close this case and open a new ticket if you have another issue later. 

//Brian

[PassionPioneer]

HI Brain,

Okay, now I am going to purchase another audio dk board to implement. Before closing this I would like to know how both audio and peripheral uart works in parallel? Anything is needed to handle from the user code.

Regards,

Naveen