PeerManager error (error: 4352)

[takashina hiroki]

I have a question about PeerManager.

When I tried bonding using PeerManager, the following error occurred.
Please tell me the cause.

<info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Bonding, error: 4352
<warning> peer_manager_handler: Disconnecting conn_handle 0.

[Jørgen Holmefjord]

Hi,

Which SDK version and example are you using? What device are you using for testing bonding against? Decimal 4352 is 0x1100. I find the following defines and reasoning for this error in peer_manager_types.h:

#define PM_CONN_SEC_ERROR_BASE 0x1000  /**< @brief The base for Peer Manager defined errors. See @ref PM_SEC_ERRORS and @ref pm_sec_error_code_t. */
#define PM_CONN_SEC_ERROR_DISCONNECT         (PM_CONN_SEC_ERROR_BASE + 0x100) /**< @brief Pairing or encryption did not finish before the link disconnected for an unrelated reason. */

So it looks like the device disconnects before the pairing or encryption procedure completed.

Best regards,
Jørgen

[Jørgen Holmefjord]

Can you provide the full log output from the failing device? If you could set NRF_LOG_DEFAULT_LEVEL to 4 in your sdk_config.h file, that should provide more details.

What device are you testing against?

Can you provide a sniffer trace between the two devices when trying to perform bonding? You can use nRFSniffer v2 for that.

[takashina hiroki]

The cause is unknown but the same phenomenon no longer occurs.
Therefore, we can not provide logs.
I will provide the log when it happens again.

The device used for the test is Android (Bluetooth v5.0).

I do not have nRF Sniffer.
Therere, sniffer trace can not be performed.

[takashina hiroki]

Is there any other way to identify the cause?
Also, I fear that this will happen at unintended timings.
Please let me know if there is a way to deal with it.

[Jørgen Holmefjord]

If you are not able to reproduce the issue anymore, and you do not have any sniffer trace that can tell what happened, there is not much you can do to figure out the issue. I would recommend that you try to stress-test your application and try every feature to try to reproduce it.

[takashina hiroki]

Yes, what you say is correct.
I make sure to reproduce.

However, I also want to know the possible causes in general.
What is the probable cause of this phenomenon?
Please tell me.

[Jørgen Holmefjord]

In security_dispacther.c, a BLE_GAP_EVT_DISCONNECTED event will directly trigger PM_CONN_SEC_ERROR_DISCONNECT. This indicates that in your application there is a BLE_GAP_EVT_CONNECTED event, security procedure started, then shortly after a BLE_GAP_EVT_DISCONNECTED event that triggers a PM_CONN_SEC_ERROR_DISCONNECT event to the application. 

[mathiasvanbelle]

I have the same thing happening in my application. But what can cause this? What can be reason of this disconnection event in security dispatcher?

Thx!