How to achieve bidirectional stream in CIS mode with LE-Audio?

[Junichi]

CIS mode using the nRF5340 Audio application
We are considering implementing a bidirectional stream.

Edit prj_release.conf as below and build/write
I did it using a script.

# nRF5340 Audio
CONFIG_NRF5340_AUDIO=y
CONFIG_STREAM_BIDIRECTIONAL=y
CONFIG_TRANSPORT_BIS=n
CONFIG_TRANSPORT_CIS=y
CONFIG_AUDIO_SOURCE_USB=n
CONFIG_AUDIO_SOURCE_I2S=y

Although it is possible to output audio from the gateway side to the headset side,
It is not possible to output sound from the headset side to the gateway side.

The build is
python buildprog.py -c both -b release -d both -m internal -M
is running.

Writing is
python buildprog.py -c both -b release -d both -m internal -M -p --recover_on_fail
is running.

Please let me know if any settings are missing.

[Karl Ylvisaker]

Hello,

What will be the contents of the return stream? Do you intend to send the microhpone data, or data from another source?
If you intend do send microphone data in the return stream from the headset device you could start out with the walkie talkie demo as suggested by Henrik.

Best regards,
Karl

[Junichi]

Thank you Karl

Was self resolved.

CONFIG_STREAM_BIDIRECTIONAL=y
When you set , you can see that the microphone on the board is enabled,
By changing the source where the microphone is enabled to line input
As expected, we were able to communicate with each other.

However, even if you press the volume button on the headset or gateway,
Only the headset volume changes.
It seems that the source itself is configured like that, but on the gateway side
I don't know which part of the source I should change to change the volume.

Please teach me.

[Karl Ylvisaker]

Hello,

I am glad to hear that you now have it working as intended! :) 

Junichi said:

However, even if you press the volume button on the headset or gateway,
Only the headset volume changes.
It seems that the source itself is configured like that, but on the gateway side
I don't know which part of the source I should change to change the volume.

Have you made sure to set CONFIG_BT_VCP_VOL_REND in your project? This will add the Volume Control Profile to your project, which is used to change the volume. This is enabled by default in the nRF5340 LE Audio reference application.

Best regards,
Karl

[Junichi]

Thank you Karl

I tried setting CONFIG_BT_VCP_VOL_REND, but the volume on the gateway side did not change as expected.

Looking at the source, it seems that the only thing that can be done is to change the volume on the headset side.

Does this need to change?

[Karl Ylvisaker]

Hello,

Junichi said:

Thank you Karl

No problem at all! :) 

Junichi said:

I tried setting CONFIG_BT_VCP_VOL_REND, but the volume on the gateway side did not change as expected.

Looking at the source, it seems that the only thing that can be done is to change the volume on the headset side.

Does this need to change?

The volume control is by default enabled in the unicast configuration of the nRF5340 LE Audio reference application - do you not see the button presses reflected in the output volume and in the logs when you press them?
If you do not, could you elaborate on what your logs say when you attempt to adjust the volume using the DK buttons?

Best regards,
Karl