How works the Broadcast Source Device with Broadcast Audio Assistant and non-nordic headset compatible Auracast.

[selim.pousse]

nrf Toolchain: 2.7.0
nrf Connect SDK : 2.7.0
Gateway: nrF5340 Audio DK
Headset: Earbud 'MOMENTUM TW 4' (Sennheiser)

I try to run and test this following application "Broadcast Source"  into the nrF5340 Audio DK (as role gateway) which should interact with auracast earbuds 'MOMENTUM TW 4' (as role headset).

As far as I understand , we need an intermediate "Broadcast Audio Assistant Device" which can be a smartphone (using nrf Connect Mobile ?), a PC, or a nrf-DK with LE audio support:

Use Case 1: Try to use the nrF5340 Audio DK (running "Broadcast Source" app) as gateway, my smartphone as Broadcast Audio Assistant Device and my auracast eardbud 'MOMENTUM TW 4' as headset.
The broadcast service of nrF5340 is published and detected by the nrf Connect mobile app. but my smartphone doesn't support the LE audio support. Is it necessary for the smartphone to support the LE Audio to manage the nrF5340 broadcast service and be able to select the advertisement or the channel wished to be listened ?

Use Case 2: Try to use a 1st nrF5340 Audio DK as gateway, a second nrF5340 Audio DK as Broadcast Audio Assistant, and auracast Headset 'MOMENTUM TW 4'
"Broadcast Audio Assistant" provided by Zephyr Project seems not working into the 2nd nrF5340-Audio-DK which play the role of the Assistant. According the doc, only nrf52840dk is supported.

*** Booting nRF Connect SDK v2.7.0-5cb85570ca43 ***
*** Using Zephyr OS v3.6.99-100befc70c74 ***
[00:00:00.415,588] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:00.415,649] <inf> bt_hci_core: HW Variant: nRF53x (0x0003)
[00:00:00.415,649] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 214.51162 Build 1926957230
[00:00:00.417,419] <inf> bt_hci_core: Identity: C6:95:06:0E:89:94 (random)
[00:00:00.417,449] <inf> bt_hci_core: HCI: version 5.4 (0x0d) revision 0x21fb, manufacturer 0x0059
[00:00:00.417,480] <inf> bt_hci_core: LMP: version 5.4 (0x0d) subver 0x21fb
Bluetooth initialized
[00:00:00.419,738] <wrn> bt_hci_core: opcode 0x2041 status 0x01
Scanning failed to start (err -5)

First, what I try to achieve makes sense ? if yes, can you help me to understand this issue of running an Broadcast Audio Assistant into a nrF5340-Audio-DK.

Thank in advance for your answers and Best Regards.

[selim.pousse]

Hi,
thank you very much for your answers. I followed your instructions to program the broadcast_audio_assistant app into the nrF5340 audio DK,
Now I'm using 2 nrF5340-audio-DKs :

• one DK playing the role of the gateway and running the Broadcast source app
  
• one other DK playing the role of the Bluetooth assistant and running the broadcast_audio_assistant app
  

Now, I have other issues :
1) the assistant DK should detect the service 'NRF5340_BROADCASTER' published by the Broadcast source DK. Why the assistant doesn't react at all in the logs ?
2) the headset (set of LE Audio Broadcast capable earbuds) should connect (or pair) to the assistant DK, why I don't see it in my provided logs above ?

[Amanda Hsieh]

It might be that the earbuds are connected by some other devices, or maybe the earbuds advertise a different name. Could you check that? 

Since the broadcast assistant should be able to scan and connect with one of the earbuds

[selim.pousse]

Hi,
The name of the earbuds is correct. And they are not connected to any other devices.
Even if the preconfigured filtering is removed from prj.conf, it doesn't change anything in the logs of the broadcast_audio_assistant app.

According the code, broadcast_audio_assistant app will at first search for and connect to the first broadcast audio sink found. 
this step seems not working because it doesn't even detect your nordic DK as a sink (nrF5340 Audio DK) which runs the broadcast_sink app.
Which means with nordic headset or non-nodic earbuds, the result is same. No reaction according the logs:

Best Regards.

[Amanda Hsieh]

Hi, 

Due to this line in the broadcast_audio_assistant, it could be that the earbuds don't advertise the needed UUID, so the broadcast assistant cannot find it. You could try to comment out Line #334 and #375 in this example.  It would work because it would check the advertised name again. 

-Amanda H.

[selim.pousse]

Thank a lot for your help, adjusting the code of broadcast_audio_assistant app did help. here the resulting logs:

[00:00:25.317,535] <inf> bt_id: NRPA: 32:98:84:94:64:98
Scanning for Broadcast Sink successfully started
Broadcast Sink Found:
  BT Name:        
'MOMENTUM' not found in names

Broadcast Sink Found:
  BT Name:        
'MOMENTUM' not found in names

Broadcast Sink Found:
  BT Name:        MOMENTUM TW 4
Match found for 'MOMENTUM'
Connecting to Broadcast Sink: MOMENTUM TW 4
Connected: 47:6B:23:F0:CF:EB (random)
[00:00:27.807,678] <inf> bt_smp: SC LTK: 0xd9c530b7db3baf6348ecb61780503ae4 (No bonding)
Security level changed: 2
BASS discover done with 1 recv states
[00:00:28.019,775] <inf> bt_id: NRPA: 0D:70:97:2C:3B:42
Scanning for Broadcast Source successfully started
Broadcast Source Found:
  BT Name:        MOMENTUM TW 4
  Broadcast Name: NRF5340_BROADCASTER
  Broadcast ID:   0x96a0b5

Match found for 'NRF5340_BROADCASTER'
Selecting Broadcast ID: 0x96a0b5
Attempting to PA sync to the broadcaster with id 0x96A0B5
Scan stopped, attempting to PA sync to the broadcaster with id 0x96A0B5
[00:00:28.107,299] <inf> bt_id: NRPA: 1B:47:71:82:6B:30
Waiting for PA synced
Broadcast Source Found:
  BT Name:        MOMENTUM TW 4
  Broadcast Name: NRF5340_BROADCASTER
  Broadcast ID:   0x96a0b5

Match found for 'NRF5340_BROADCASTER'
bt_le_scan_stop failed with -120
Selecting Broadcast ID: 0x96a0b5
Attempting to PA sync to the broadcaster with id 0x96A0B5
Broadcast Source Found:
  BT Name:        MOMENTUM TW 4
  Broadcast Name: NRF5340_BROADCASTER
  Broadcast ID:   0x96a0b5

Match found for 'NRF5340_BROADCASTER'
bt_le_scan_stop failed with -120
Selecting Broadcast ID: 0x96a0b5
Attempting to PA sync to the broadcaster with id 0x96A0B5
PA sync 0x20002324 synced for broadcast sink with broadcast ID 0x96A0B5
BASS add source successful

I was able to hear the music broadcast into the earbuds at the first attempt   (but with a poor sound quality).
But unfortunately, afterwards from the 2nd attempt, I was not able anymore to hear anything and to reproduce the same result...

Additional Notes:
Now, I was able to listen multiple times to the broadcast audio stream but still with very poor sound quality
How I can configure, control or improve the sound quality from the broadcast source app ?

Best Regards.