nrf5340 bluetooth connection error

[mjpark]

Hello,

I am currently testing a custom board using the nRF5340QKAA.

Most of the connections are the same as the nRF5340 DK, but the main difference is that I built the board without an external 32k clock.

I am testing the peripheral UART example. On the DK board, I confirmed that advertising and connection work fine. However, when using my custom board, initially, nothing was detected during scanning.

To enable the internal clock, I first set:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

However, when I tried to scan for the device using the nRF Connect app, it still did not show up. So, I added:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_SYNTH=y
After adding this configuration, I was able to scan and detect the device successfully.

The problem now is that when I try to connect using the nRF Connect app, it immediately disconnects with the error:
Error 133(0x83): GATT ERROR

Can you help me troubleshoot this issue?

[mjpark]

I am currently using the TE Connectivity AMP Connectors 2108792-2 antenna, connected to the ANT pin of the nRF5340.

[Jared]

Hi,

Which SDK version are you using?

To enable the internal clock, I first set:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

However, when I tried to scan for the device using the nRF Connect app, it still did not show up. So, I added:
CONFIG_CLOCK_CONTROL_NRF_K32SRC_SYNTH=y
After adding this configuration, I was able to scan and detect the device successfully.

Did you check that this was applied to the fw that was flashed to the network core as well? RC should work.

Error 133(0x83): GATT ERROR

This error is from the nRF Connect app? Did you get any output on the log from the nRF5340 when it disconnects?

mjpark said:

I am currently using the TE Connectivity AMP Connectors 2108792-2 antenna, connected to the ANT pin of the nRF5340.

On your custom board, do you have a matching network for the radio?

Would it be possible for you to share your design?

I can make the case private first if you prefer it.

regards

Jared

[mjpark]

Hello,

Jared said:

Which SDK version are you using?

I am currently using SDK version 2.8.0.

Jared said:

Did you check that this was applied to the fw that was flashed to the network core as well? RC should work.

I also want to verify the settings, but I am not sure exactly where to check.

Currently, I manually added the configurations in two locations within the project folder:

1. prj.conf inside the project folder
2. sysbuild/ipc_radio inside the project folder

regards

mjpark

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From additional testing, the connection was successfully established, but it seems to disconnect during the send_ble_message or bt_nus_send process.

[mjpark]

I am not very familiar with the Q&A section of this website, so if I fail to respond due to my mistake, please send me a message. Thank you!

[Jared]

Hi,

Can you share your build folder after you have built the project?

mjpark said:

I see from the log from the nRF5340 that it fails to send a message before it disconnects. Can you try to use the debugger and find the function that returns err -22?

I suspected that it was this line, but the log output isn't quite the same:

Do you have a nRF5340 DK that you can test with? Can you try connecting that antenna to the SWF port on the DK and see if it works with the development kit?

regards

Jared