optimizing nRF5340 Audio application for maximum range

[JeraDrson]

Hello,

I am working on unidirectional voice broadcasting device where the maximum range is the priority. At this time I am developing on Audio DK boards.

I need some help to choose the correct settings.

16KHz/16b, single stream (mono) quality is good enough, audio latency is not important

I need some few bytes short custom data advertisement about 5x per second. No other communication is needed.

I made some adjustments in nRF Kconfig GUI to select the audio format, audio works but it is hard to tell the the sittings is close to optimal (tested outdoor range is about 150m with optimal antenna orientation).

I understand setting the device to coded PHY should help, however I do not know how to do that.

I added

CONFIG_BT_CTLR_PHY_CODED=y

CONFIG_BT_EXT_ADV=y

CONFIG_BT_USER_PHY_UPDATE=y

to the prj.conf but i get message that CONFIG_BT_CTLR_PHY_CODED  was set to n because of dependencies. I could not find any related options in kconfig editor.

Also how can i determine the number of retransmissions?

Thank you

Regards Jeronym

[Amanda Hsieh]

Hi,

Which NCS version are you using?

I added

CONFIG_BT_CTLR_PHY_CODED=y

CONFIG_BT_EXT_ADV=y

CONFIG_BT_USER_PHY_UPDATE=y

to the prj.conf

Please try to add those configs to hci_ipc.conf.

Regards,
Amanda H.

[JeraDrson]

v 2.6.1

I moved the option to hci_ipc.conf (i tried it before).

I cleared the project, restarted to visual studio and i no longer see the dependencies issues. Is there a way to know ir is really working? Maybe some debug prints?

[Amanda Hsieh]

Hi, 

How/What command do you build the application? The default prj.conf would provide full logging capabilities and debug optimizations to ease development.

Regards,
Amanda H.

[JeraDrson]

To be sure i have just created new build configuration. I left all the options untouched.

This is strange because i can now see the message with dependencies again.

I can see some information about the audio stream for example but nothing about PHY settings.

I also quickly tested the range and it seems about the same as before adding the options.

[Amanda Hsieh]

You should add the configs as this hci_ipc.conf:

CONFIG_BT_EXT_ADV=y
CONFIG_BT_CTLR_ADV_EXT=y
CONFIG_BT_CTLR_PHY_CODED=y

Make sure you add the coded PHY settings on both devices.