BLE connection issue (error 8) with nRF54H20 + Zephyr

[Mykhaylo]

Hello,

We have the following environment:

1) nRF54H20-DK v0.9.1 and our custom board

2) nRF Connect SDK v3.2.1

3) Our simple project for testing BLE

4) nRF Connect for Mobile app

5) Our custom board has an external 32.768 kHz crystal

Before testing we have connected and bonded our device with nRF Connect for Mobile app.

Then we turn device off and on (power cycle) and try to connect to our device from app.

If we use nRF54H20-DK the connection is established successfully every time.

If we use our custom board sometimes we get the connection error 8. Both device and app show this error.

Also we have other samples of our custom boards. Some of them work well, but some ones have the same connection issue.

How can we debug and fix the issue?

Thanks

[Amanda Hsieh]

Hi, 

Also we have other samples of our custom boards. Some of them work well, but some ones have the same connection issue.

The disconnect reason 8 is BT_HCI_ERR_CONN_TIMEOUT, which means the supervision timeout. You can refer to those workable samples to increase the supervision timeout.

Regards,
Amanda H.

[Mykhaylo]

How can we increase supervision timeout?

Mykhaylo

[Mykhaylo]

log-connect-error-8.pcapng

[Amanda Hsieh]

The communication in the log is encrypted. Could you temporarily disable it and provide the log again? 

[Mykhaylo]

log-connect-error-8-disable-encryption.pcapng

[Mykhaylo]

This is one more log when connection was established successfully

log-connect-without-error.pcapng

[Amanda Hsieh]

Both log-connect-error-8.pcapng and log-connect-error-8-disable-encryption.pcapng show that the peripheral side didn't respond to the central side, which then caused the disconnection. 

Are you testing with your app or the NCS samples?

Also we have other samples of our custom boards. Some of them work well, but some ones have the same connection issue.

Does it only happen to the specific custom board? If so, it might be the HW issue. Did you have the PCB reviewed by us? If not, you can create a private case with the title "nRF54H20 PCB review".  

[Mykhaylo]

 As I wrote above

• If we use nRF54H20-DK the connection is established successfully every time.
• If we use our custom board sometimes we get the connection error 8. Both device and app show this error.
• Also we have other samples of our custom boards. Some of them work well, but some ones have the same connection issue.

[Amanda Hsieh]

Mykhaylo said:

Also we have other samples of our custom boards. Some of them work well, but some ones have the same connection issue.

If the same code can work on some of your custom boards, but some ones have a connection issue. Then, I would suggest you check the hardware.

Your .pcapng logs show the peripheral side didn't interact with the central.