case about nRF52840 ble_app_hrs Encryption, error: 4102

RE: case about nRF52840 ble_app_hrs Encryption, error: 4102

peter.min — Tue, 07 Nov 2023 07:58:57 GMT

Hi Simonr,

1. Thank you for your reply,

2. The cause of the problem is:

After power off, the red box part of the TAB is directly connected to the DK board without closing

3. It can be regarded as an app bug

Thank you for all your assistance.
Kind regards,
Peter.Min

RE: case about nRF52840 ble_app_hrs Encryption, error: 4102

Simonr — Mon, 06 Nov 2023 09:26:09 GMT

Hi Peter

In the ble_app_hrs example project, you can see that the delete_bonds(); function is called in advertising_start() if the erase_bonds bool is set as it is by default. So upon a power reset the device will erase bonding information when it starts advertising which is why you see this issue on your end I think.

Best regards,

Simon

RE: case about nRF52840 ble_app_hrs Encryption, error: 4102

peter.min — Sat, 04 Nov 2023 08:52:59 GMT

Hi Simonr,

1. I know the method you provided can solve this problem.

2. I provide a method for problem recurrence here.

3. What I want to investigate is why the binding information is dropped here and whether it is a bug in the sdk.

4. If this is not a bug in the sdk, how can the customer use the pairing and binding information to avoid interrupting the user's use?

5.In the past, I have set up the program to allow repairing, but this is not a good experience for interrupted customers

Thank you for all your assistance.
Kind regards,
Peter.Min

RE: case about nRF52840 ble_app_hrs Encryption, error: 4102

Simonr — Fri, 03 Nov 2023 08:39:27 GMT

Error message 0x4102 comes from one of the devices indicating that it already has stored bonding information on the other device, while the other does not. Either the nRF52840 or the phone has stored bonding information on the other device already, and you need to erase bonding information on that device to resolve this. On the nRF side you can do so by doing an nrfjprog --recover or --eraseall, and on the phone side (in the nRF Connect app) you must select the device in the "BONDED" tab and press "Delete bond information" for the device you're trying to bond to now.

More details on this error message is discussed in this ticket: peer_manager_handler: Connection security failed: role: Peripheral, conn_handle: 0x0, procedure: Encryption, error: 4102

Best regards,

Simon