Connecting NRF5340 to ear buds

[Richard Taft]

Hello,

I am new to Bluetooth. I have two nrf5340 LE Audio SDKs which I have been able to configure and use as gateway and headset (walkie talkie, USB, and line-in, CIS and BIS). Now the next step is I want to connect the gateway to a third party headset or ear bud to stream audio. I connected the gateway to the serial terminal on my PC through NRF connect which prints out the following at startup. I have not been able to connect to any earbuds (classic or BLE). I have tried earbuds with BT 5.0, 5.1, and 5.3. Seems the gateway needs to provide a list of connectable devices to choose from. How is this done?

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
GW [00:00:00.269,836] <inf> board_version: Compatible board/HW version found: 1.0.0
GW [00:00:00.304,321] <inf> sd_card: SD card volume size: 30941380608 B
GW [00:00:00.308,166] <inf> fw_info:
nRF5340 Audio nRF5340 Audio DK cpuapp
NCS base version: 2.9.0
Cmake run : Tue Mar 04 09:59:45 2025
GW [00:00:00.308,166] <inf> fw_info: ------- DEBUG BUILD -------
GW [00:00:00.308,166] <inf> fw_info: Compiled for GATEWAY device
GW [00:00:00.338,500] <inf> bt_mgmt_ctlr_cfg: Controller: SoftDevice: Version 6.0 (0x0e), Revision 8299
GW [00:00:00.338,714] <inf> bt_mgmt: Local identity addr: CF:33:22:1D:A1:B8 (random)
GW [00:00:00.366,882] <inf> broadcast_source: Enabling broadcast_source 0
GW [00:00:00.369,567] <inf> main: Broadcast source: NRF5340_BROADCASTER started
GW [00:00:00.370,666] <inf> bt_mgmt_adv: Local addr: 35:E1:69:8E:57:04 (random)
GW [00:00:00.372,711] <inf> main: Ext adv ready
GW [00:00:00.373,443] <inf> bt_mgmt_adv: Advertising successfully started
GW [00:00:00.381,286] <inf> broadcast_source: Broadcast source 0x2000da8c started
GW [00:00:00.381,317] <inf> le_audio: LC3 codec config for source:
GW [00:00:00.381,317] <inf> le_audio: Frequency: 48000 Hz
GW [00:00:00.381,317] <inf> le_audio: Duration: 10000 us
GW [00:00:00.381,317] <inf> le_audio: Channel allocation: 0x1
GW [00:00:00.381,347] <inf> le_audio: Octets per frame: 120 (96000 bps)
GW [00:00:00.381,347] <inf> le_audio: Frames per SDU: 1
GW [00:00:00.381,774] <inf> broadcast_source: Broadcast source 0x2000dab4 started
GW [00:00:00.381,805] <inf> le_audio: LC3 codec config for source:
GW [00:00:00.381,805] <inf> le_audio: Frequency: 48000 Hz
GW [00:00:00.381,805] <inf> le_audio: Duration: 10000 us
GW [00:00:00.381,805] <inf> le_audio: Channel allocation: 0x2
GW [00:00:00.381,805] <inf> le_audio: Octets per frame: 120 (96000 bps)
GW [00:00:00.381,805] <inf> le_audio: Frames per SDU: 1
GW [00:00:00.409,301] <inf> audio_datapath: Drft comp state: CALIB
GW [00:00:00.509,277] <inf> audio_datapath: Drft comp state: INIT
GW [00:00:00.510,284] <inf> audio_datapath: Drft comp state: CALIB
GW [00:00:00.610,290] <inf> audio_datapath: Drft comp state: OFFSET
GW [00:00:01.010,559] <inf> audio_datapath: Drft comp state: LOCKED

Thank you,

Rich

[dejans]

Hi,

Which BLE earbuds have you tried to use?

Have you checked that your selected earbuds support LE Audio?

Best regards,
Dejan

[Richard Taft]

Yes, I have tried various ear buds that support Bluetooth 5.0, 5.1, 5.3, and today I tried 5.4. My understanding is that all of these are BLE using the LC3 Codec.

I have connected to my SDK using nRF Connect and J-Link. The J-Link connects to my SDK but the scanning function is disabled. It says "Note: no pre-compiled firmware is available for the selected device..." What pre-compiled firmware should I have?

Thank you,

Rich

[dejans]

Hi Rich,

Richard Taft said:

I have tried various ear buds that support Bluetooth 5.0, 5.1, 5.3, and today I tried 5.4. My understanding is that all of these are BLE using the LC3 Codec.

You could look at the documentation for the buds to check if there is LE Audio support. Which specific buds did you try to use?

Richard Taft said:

I have connected to my SDK using nRF Connect and J-Link. The J-Link connects to my SDK but the scanning function is disabled. It says "Note: no pre-compiled firmware is available for the selected device..." What pre-compiled firmware should I have?

Where did you see the message "Note: no pre-compiled firmware is available for the selected device..."?
Which steps did you take before seeing this message?

Best regards,
Dejan

[Richard Taft]

I've tried several. My understanding is that anything that uses the LC3 Codec is LE. Bluetooth 5.0+ all support LC3. Do I have this wrong? So yes, I have verified LE. I just bought this one which is 5.4. I think the gateway is not setup to scan for anything other than another SDK.

www.amazon.com/.../B0DSKN15PV

[dejans]

Hi,

dejans said:

Where did you see the message "Note: no pre-compiled firmware is available for the selected device..."?
Which steps did you take before seeing this message?

Can you answer these questions as well?

Best regards,
Dejan

[Richard Taft]

Hi Dejan,

Thanks for your help. It is quite apparent I do not have a good handle of this system. I am using NRF Connect for Desktop Standalone V4.04. I have opened the Bluetooth Low Energy app and selected my nRF5340 LE Audio SDK Gateway with J-Link via USB.

The 'start scan' button is grayed out. I get the following in the log. I have also used the nRFConnect Mobility on my phone to find the earbuds. While it finds the SDKs and other devices, it does not find any LE earbuds. Yet me iphone can connect and stream to those earbuds. Same with an Andriod phone.

What steps should I try to take to connect my SDK gateway to LE earbuds? As mentioned, the SDKs find each other and stream just fine.

2025-03-07T18:38:47.978Z INFO Server setup was cleared
2025-03-07T18:38:51.698Z INFO Selected device with s/n 001050185387
2025-03-07T18:38:51.834Z INFO Connected to device with serial number: 001050185387 and family: NRF53
2025-03-07T18:38:51.834Z INFO Note: no pre-compiled firmware is available for the selected device. You may still use the app if you have programmed the device with a compatible firmware.
2025-03-07T18:38:51.835Z INFO Device setup completed
2025-03-07T18:38:51.835Z INFO The device is not in the list of supported devices. Attempting to open as a custom device.
2025-03-07T18:38:51.835Z INFO Opening custom device
2025-03-07T18:38:51.835Z INFO Note: firmware must be compatible with connectivity firmware version: 4.1.4, SoftDevice API version: 5 and baud rate: 1000000.
2025-03-07T18:38:51.835Z INFO Opening adapter connected to COM25
2025-03-07T18:38:52.763Z INFO Successfully opened COM25. Baud rate: 1000000. Flow control: none. Parity: none.
2025-03-07T18:38:52.764Z DEBUG State change: STATE_START -> STATE_RESET
2025-03-07T18:38:52.764Z DEBUG 1 -> [N/A] type: RESERVED_5 reliable: no seq#:0 ack#:0 payload_length:0 data_integrity:0 err_code:0x0
2025-03-07T18:38:52.764Z INFO Reset performed on adapter COM25
2025-03-07T18:38:53.064Z DEBUG State change: STATE_RESET -> STATE_UNINITIALIZED
2025-03-07T18:38:53.064Z DEBUG 2 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T18:38:53.315Z DEBUG 3 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T18:38:53.566Z DEBUG 4 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T18:38:53.816Z DEBUG 5 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T18:38:54.067Z DEBUG 6 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T18:38:54.317Z DEBUG 7 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T18:38:54.568Z DEBUG State change: STATE_UNINITIALIZED -> STATE_NO_RESPONSE
2025-03-07T18:38:54.568Z ERROR Received status with code 0 PKT_SEND_MAX_RETRIES_REACHED, message: 'No response from device. Tried to send packet 6 times.'
2025-03-07T18:38:55.764Z DEBUG serial port read on port COM25 aborted.
2025-03-07T18:38:55.764Z INFO serial port COM25 closed.
2025-03-07T18:38:55.770Z ERROR Error occured when opening port. Errorcode: NRF_ERROR_TIMEOUT (0xd)

[Richard Taft]

This is log more updated. I am not sure what COM25 is doing but me device manager says it is connected. 

2025-03-07T22:07:33.008Z DEBUG Application data folder: C:\Users\RichardT\AppData\Roaming\nrfconnect-bluetooth-low-energy\bundle
2025-03-07T22:07:33.055Z INFO Using nrf-device-lib-js version: 0.4.4
2025-03-07T22:07:33.056Z INFO Using nrf-device-lib version: 0.10.3
2025-03-07T22:07:33.056Z INFO Using nrfjprog DLL version: 10.15.1
2025-03-07T22:07:33.056Z INFO Using JLink version: JLink_V8.18
2025-03-07T22:07:33.071Z DEBUG App pc-nrfconnect-ble v4.0.4 official
2025-03-07T22:07:33.071Z DEBUG App path: C:\Users\RichardT\AppData\Local\Programs\nrfconnect-bluetooth-low-energy\resources\app.asar\resources/bundle/
2025-03-07T22:07:33.071Z DEBUG nRFConnect 4.0.4, required by the app is (^3.8.0)
2025-03-07T22:07:33.071Z DEBUG nRFConnect path: C:\Users\RichardT\AppData\Local\Programs\nrfconnect-bluetooth-low-energy\resources\app.asar
2025-03-07T22:07:33.071Z DEBUG HomeDir: C:\Users\RichardT
2025-03-07T22:07:33.071Z DEBUG TmpDir: C:\Users\RichardT\AppData\Local\Temp
2025-03-07T22:07:33.072Z INFO Installed JLink version does not match the provided version (V7.66a)
2025-03-07T22:07:33.237Z INFO Updated list of uuids with data from github.com/.../v1
2025-03-07T22:07:38.440Z INFO Selected device with s/n 001050185387
2025-03-07T22:07:38.576Z INFO Connected to device with serial number: 001050185387 and family: NRF53
2025-03-07T22:07:38.577Z INFO Note: no pre-compiled firmware is available for the selected device. You may still use the app if you have programmed the device with a compatible firmware.
2025-03-07T22:07:38.578Z INFO Device setup completed
2025-03-07T22:07:38.578Z INFO The device is not in the list of supported devices. Attempting to open as a custom device.
2025-03-07T22:07:38.578Z INFO Opening custom device
2025-03-07T22:07:38.578Z INFO Note: firmware must be compatible with connectivity firmware version: 4.1.4, SoftDevice API version: 5 and baud rate: 1000000.
2025-03-07T22:07:38.579Z INFO Opening adapter connected to COM25
2025-03-07T22:07:39.508Z INFO Successfully opened COM25. Baud rate: 1000000. Flow control: none. Parity: none.
2025-03-07T22:07:39.508Z DEBUG State change: STATE_START -> STATE_RESET
2025-03-07T22:07:39.508Z DEBUG 1 -> [N/A] type: RESERVED_5 reliable: no seq#:0 ack#:0 payload_length:0 data_integrity:0 err_code:0x0
2025-03-07T22:07:39.509Z INFO Reset performed on adapter COM25
2025-03-07T22:07:39.810Z DEBUG State change: STATE_RESET -> STATE_UNINITIALIZED
2025-03-07T22:07:39.810Z DEBUG 2 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T22:07:40.059Z DEBUG 3 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T22:07:40.310Z DEBUG 4 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T22:07:40.560Z DEBUG 5 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T22:07:40.811Z DEBUG 6 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T22:07:41.063Z DEBUG 7 -> [01 7e ] type: LINK_CONTROL_PACKET reliable: no seq#:0 ack#:0 payload_length:2 data_integrity:0 err_code:0x0 [SYNC]
2025-03-07T22:07:41.314Z DEBUG State change: STATE_UNINITIALIZED -> STATE_NO_RESPONSE
2025-03-07T22:07:41.314Z ERROR Received status with code 0 PKT_SEND_MAX_RETRIES_REACHED, message: 'No response from device. Tried to send packet 6 times.'
2025-03-07T22:07:42.508Z DEBUG serial port read on port COM25 aborted.
2025-03-07T22:07:42.624Z ERROR Error occured when opening port. Errorcode: NRF_ERROR_TIMEOUT (0xd)