Connecting nRF5340 LE Audio to other LE Audio equipment

[hakved_vea]

Hi,

I'm trying to connect the nRF5340 LE Audio example to another LE Audio equipment: VOCE by Nexum (https://www.nexum-design.com/) 

I asked Nexum if this was possible and got this reply:

Hi, This is totally ok if you set VOCE as Auracast TX mode. but please note, the standard sample rate of Auracast is 24K sample rate. And VOCE now is set by 48Kh. We will upgrade our VOCE to support 16 / 24Khz by next upgrade. now, you need to make sure nRF5340 as Auracast RX device can also support 16bit/48K sample rate. BR, NEXUM

I also opened a ticket on DevZone earlier but thought this got a little off topic, 

 Building nRF5340_audio example for nRF5340-DK (not NRF5340-AUDIO-DK) 

I was able to build the example and connect two nRF5340-Audio-DK kits. 

Do you have any advice for how to attack this?

I'm currently trying out different config parameters in addition to adding LOG_INF(...) to see if nRF5340 sees the VOCE device. But i have't got any closer..

Thanks in advance for any reply on this,

Best,

Håkon 

[dejans]

Hi Håkon,

hakved_vea said:

I edited line 320 in le_audio_bis_headset.c:

hakved_vea said:

so that is selected both indexes BIT(1) and BIT(2). This is what ISO Receive had in the sync parameters.

Could you show these sync parameters in ISO Receive?

hakved_vea said:

I'm a bit lost in why this work and why setting bis_bitfields to the correct value causes the nRF5340 to crash?

What is the correct value? Which value works and which doesn't work? Do you have a log showing the crash?

Best regards,
Dejan

[dejans]

Hi Håkon, 

hakved_vea said:

When listening to songs I can recognize the song playing, however it sounds broken.

How did you verify that the sound is broken? How does it sound broken?

hakved_vea said:

I see that from the terminal printout that:
nRF5340 have define Channel allocation: 0x1
while VOCE sets Channel allocation: 0x0
What implications does this have?

Could you show the terminal output?

Best regards,
Dejan

[dejans]

Hi Håkon,

hakved_vea said:

I assume that some of these differences is handled by the LE Audio implementation, can you help me point out the differences that is not supported by the example code?

Could you please rephrase your question?

hakved_vea said:

alos at line 264 in broadcast_source.c

hakved_vea said:

I see this comment on line 339 in broadcast_source.c

hakved_vea said:

is this something that you are currently working on?

Currently supported features can be seen in the feature support matrix.

Best regards,
Dejan

[dejans]

Hi Håkon,

You mentioned previously that you worked with nRF5340_audio sample, but you also mentioned programming the board with ISO Receive sample. Could you specify whether you used nrf5340_audio sample or ISO Receive sample as a starting point which you later modified?

How did you build and flash your application?

Best regards,
Dejan

[hakved_vea]

Hi Dejan,

I will try to clarify a bit.

I created a new application in VSCode trough the nRF Connect extension using SDK version 2.2.0. I selected the nRF5340_Audio example and have used that as a baseline for modification. 

I only used to ISO Receive example as reference since it provided me with more information about the advertisement data.

I think the issue I have is regards to the synchronization of the BIS streams. I see that the I2S and the LC3 codec handles stereo, and that both channels is sent in the stream. However in the sync adv data it only specify on channel (as nRF5340 can only play mono on left channel). And the difference between VOCE and nRF5340 is that the channels is specifyed per bis in VOCE and set as a common configuration in nRF5340, this is specifyed in the sync adv data. 

Hope this clearyfies a little :)

dejans said:

hakved_vea said:

I assume that some of these differences is handled by the LE Audio implementation, can you help me point out the differences that is not supported by the example code?

Could you please rephrase your question?

I have noticed from the LE Audio specifications that it is highly configurable and flexible and how to connect to broadcast source is specified in the advertisement data. So my question is, does nRF5340 Audio support all possible configurations sent in advertisement data? 

Best regards,
Håkon