nRF audio DK reference application not visible to smartphone scan

[ermalh]

Hello,

I am evaluating the nRF5340 for a potential BLE audio application. I was able to program the kit following the instructions and using the build script (or through VScode), however the unit is not discoverable and I am not able to find it via bluetooth scan from my iphone or from my laptop. I am able to see the device using the mobile app "nRF Connect for Mobile" but this one shows issues as well when connecting to it. Is this something that anyone else has exhibited before?

Additionally (but less important for the purpose of my evaluation) it is not clear from the link https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/nrf5340_audio/index.html how to program the unit to be a left/right channel or (if it is possible) to program it as duo when using VS code.

Thank you for your support!

[dejans]

Hi,

ermalh said:

I am able to program the unit to right channel or left channel (the LED color updates) but the unit is never discoverable via bluetooth scan.

You could test if the application works as expected when you use both headset and gateway devices. You could also try to build the application only for headset device using "-d headset" option in your buildprog command. What are the results?

How did you do Bluetooth scanning?

Best regards,
Dejan

[ermalh]

Hi Dejan,

I tried to program it as gateway from VScode, I used the nRF Kconfig GUI to change the configuration and I was able to see the device once after scanning for bluetooth devices with my laptop. I tried to connect to the device but without success (connecting...)

I used various devices (laptop and iphones) to scan for the nrf5340. I was able to detect it only once after so many different tries.

I have no clue if there is anything I am doing wrong or if there is a bug somewhere in the example code.

[dejans]

Hi,

Are you using 2 different devices that you programmed as headset and gateway, or do you have only one device which you previously programmed as headset and now as gateway?

ermalh said:

I tried to connect to the device but without success (connecting...)

Can you show this "connecting ..." status?

ermalh said:

I used various devices (laptop and iphones) to scan for the nrf5340. I was able to detect it only once after so many different tries.

How did you perform the scan? Which application did you use on the laptop and iPhones? Did you try with Android phone?

ermalh said:

I used the nRF Kconfig GUI to change the configuration and I was able to see the device once after scanning for bluetooth devices with my laptop.

Which configuration changes have you made? Have you tried editing the configuration without using Kconfig GUI?

Best regards,
Dejan

[ermalh]

Hi Dejan,

dejans said:

How did you perform the scan? Which application did you use on the laptop and iPhones? Did you try with Android phone?

I don't use any application, I am scanning for available bluetooth devices using my iphone or my windows laptop. I did not try an android phone.

dejans said:

Are you using 2 different devices that you programmed as headset and gateway, or do you have only one device which you previously programmed as headset and now as gateway?

I am using a single device. The purpose is to evaluate the LE audio DK and the possibility to use this platform for the development of a headset.

dejans said:

Can you show this "connecting ..." status?

When I use my laptop or iphone, the NRF5340_AUDIO device is not discoverable. However, when I use the nRF connect mobile app, I am able to see the device NRF5340_AUDIO. When connecting to it, the app seems to hang in the "Connecting" state for a minute. The serial log of the device looks like this:

HL [00:15:59.873,474] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:01.154,357] <inf> bt_mgmt: Directed adv timed out with no connection, reverting to normal adv
HL [00:16:01.157,287] <inf> bt_mgmt_adv: Local addr: 73:7D:73:4E:07:29 (random)
HL [00:16:01.158,203] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:02.850,494] <inf> bt_mgmt: Connected: F8:C3:CC:16:E3:ED (public)
HL [00:16:02.850,524] <inf> main: Connected
HL [00:16:03.021,087] <inf> bt_mgmt: Disconnected: F8:C3:CC:16:E3:ED (public) (reason 0x3e)
HL [00:16:03.021,087] <inf> main: Disconnected
HL [00:16:03.021,118] <wrn> bt_content_ctrl_media: Unable to look up conn pointer: -3
HL [00:16:03.021,118] <err> bt_content_ctrl: bt_content_ctrl_media_conn_disconnected failed with -3
HL [00:16:03.022,735] <inf> bt_mgmt_adv: Local addr: 73:7D:73:4E:07:29 (random)
HL [00:16:03.022,827] <inf> bt_mgmt_adv: Adv directed to: F8:C3:CC:16:E3:ED (public).
HL [00:16:03.023,437] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:04.304,321] <inf> bt_mgmt: Directed adv timed out with no connection, reverting to normal adv
HL [00:16:04.307,250] <inf> bt_mgmt_adv: Local addr: 76:05:04:36:2E:D3 (random)
HL [00:16:04.308,166] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:09.780,120] <inf> bt_mgmt: Connected: F8:C3:CC:16:E3:ED (public)
HL [00:16:09.780,151] <inf> main: Connected
HL [00:16:09.951,904] <inf> bt_mgmt: Disconnected: F8:C3:CC:16:E3:ED (public) (reason 0x3e)
HL [00:16:09.951,934] <inf> main: Disconnected
HL [00:16:09.951,934] <wrn> bt_content_ctrl_media: Unable to look up conn pointer: -3
HL [00:16:09.951,965] <err> bt_content_ctrl: bt_content_ctrl_media_conn_disconnected failed with -3
HL [00:16:09.953,582] <inf> bt_mgmt_adv: Local addr: 76:05:04:36:2E:D3 (random)
HL [00:16:09.953,643] <inf> bt_mgmt_adv: Adv directed to: F8:C3:CC:16:E3:ED (public).
HL [00:16:09.954,284] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:11.235,168] <inf> bt_mgmt: Directed adv timed out with no connection, reverting to normal adv
HL [00:16:11.238,098] <inf> bt_mgmt_adv: Local addr: 76:D0:4D:1F:15:D8 (random)
HL [00:16:11.239,013] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:13.352,355] <inf> bt_mgmt: Connected: F8:C3:CC:16:E3:ED (public)
HL [00:16:13.352,386] <inf> main: Connected
HL [00:16:13.521,667] <inf> bt_mgmt: Disconnected: F8:C3:CC:16:E3:ED (public) (reason 0x3e)
HL [00:16:13.521,667] <inf> main: Disconnected
HL [00:16:13.521,697] <wrn> bt_content_ctrl_media: Unable to look up conn pointer: -3
HL [00:16:13.521,697] <err> bt_content_ctrl: bt_content_ctrl_media_conn_disconnected failed with -3
HL [00:16:13.523,315] <inf> bt_mgmt_adv: Local addr: 76:D0:4D:1F:15:D8 (random)
HL [00:16:13.523,406] <inf> bt_mgmt_adv: Adv directed to: F8:C3:CC:16:E3:ED (public).
HL [00:16:13.524,017] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:14.804,901] <inf> bt_mgmt: Directed adv timed out with no connection, reverting to normal adv
HL [00:16:14.807,830] <inf> bt_mgmt_adv: Local addr: 71:C8:74:03:0A:A2 (random)
HL [00:16:14.808,746] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:16.065,765] <inf> bt_mgmt: Connected: F8:C3:CC:16:E3:ED (public)
HL [00:16:16.065,795] <inf> main: Connected
HL [00:16:16.222,595] <inf> bt_mgmt: Disconnected: F8:C3:CC:16:E3:ED (public) (reason 0x3e)
HL [00:16:16.222,625] <inf> main: Disconnected
HL [00:16:16.222,625] <wrn> bt_content_ctrl_media: Unable to look up conn pointer: -3
HL [00:16:16.222,625] <err> bt_content_ctrl: bt_content_ctrl_media_conn_disconnected failed with -3
HL [00:16:16.224,243] <inf> bt_mgmt_adv: Local addr: 71:C8:74:03:0A:A2 (random)
HL [00:16:16.224,334] <inf> bt_mgmt_adv: Adv directed to: F8:C3:CC:16:E3:ED (public).
HL [00:16:16.224,945] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:17.505,828] <inf> bt_mgmt: Directed adv timed out with no connection, reverting to normal adv
HL [00:16:17.508,789] <inf> bt_mgmt_adv: Local addr: 57:01:2A:0E:98:CF (random)
HL [00:16:17.509,704] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:20.258,697] <inf> bt_mgmt: Connected: F8:C3:CC:16:E3:ED (public)
HL [00:16:20.258,728] <inf> main: Connected
HL [00:16:20.421,783] <inf> bt_mgmt: Disconnected: F8:C3:CC:16:E3:ED (public) (reason 0x3e)
HL [00:16:20.421,783] <inf> main: Disconnected
HL [00:16:20.421,813] <wrn> bt_content_ctrl_media: Unable to look up conn pointer: -3
HL [00:16:20.421,813] <err> bt_content_ctrl: bt_content_ctrl_media_conn_disconnected failed with -3
HL [00:16:20.423,431] <inf> bt_mgmt_adv: Local addr: 57:01:2A:0E:98:CF (random)
HL [00:16:20.423,522] <inf> bt_mgmt_adv: Adv directed to: F8:C3:CC:16:E3:ED (public).
HL [00:16:20.424,133] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:21.705,017] <inf> bt_mgmt: Directed adv timed out with no connection, reverting to normal adv
HL [00:16:21.707,946] <inf> bt_mgmt_adv: Local addr: 4E:A6:8A:D7:DF:6D (random)
HL [00:16:21.708,862] <inf> bt_mgmt_adv: Advertising successfully started
HL [00:16:23.193,054] <inf> bt_mgmt: Connected: F8:C3:CC:16:E3:ED (public)
HL [00:16:23.193,084] <inf> main: Connected
HL [00:16:23.569,244] <inf> main: Security changed
HL [00:16:23.629,211] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a
HL [00:16:23.718,963] <err> bt_content_ctrl_media: Discovery of MCS failed (-61)

It seems like it connects and tries cyclically to establish a connection until it eventually stops with the following message:

<err> bt_content_ctrl_media: Discovery of MCS failed (-61)

At this point the nRF mobile connect app shows as in the "Connected" state. I am able to see all the services through the app. But I am unable to connect it as an audio device to my laptop or iphone.

Is this behavior normal and expected or could it be the reason that my audio DK is not discoverable and cannot connect to my iphone/laptop? 

[ermalh]

Hi Dejan, as we can see in the log, the unit disconnects regularly about 160-170ms after connecting.

Do you have any recommendations?