BLE_APP_TEMPLATE connection ecryption error in SDK 15.1

[Ars Morozov]

Hello. I've migrated my application from SDK 14.2 to 15.1 and I obtain this strange message from peer_manager_handler in my log: 

<info> peer_manager_handler: Connection security failed: role: Peripheral, conn_handle: 0x0, procedure: Encryption, error: 4102

I obtain this message only when I connect with nRF_Connect app on Iphone. When I connect with Android everything is fine.


My application is based on ble_app_template. So, I upload clean ble_app_template from SDK 15.1 and still obtain this message. When I check it on ble_app_template from SDK 14.2, message is disapear.

What does this message mean? And have can I deal with it?

[Einar Thorsrud]

Hi,

I have not been able to reproduce this on my side using an unmodified Template Application from SDK 15.1 and nRF Connect 1.8.7 on iOS. Can you elaborate on how you were able to trigger his issue, and describe any modifications you have done to the Template Application?

[Ars Morozov]

I just upload template application on nRF52DK (pca10040) without any modifications of project and connect with nRF Connect 1.8.7 on iOS (iPhone 6). 
When I connect with Android this message is disapear.

[Ars Morozov]

It's not completely random, because I try to do it many times it and this problem is occure with this conditions. Maybe it's related with device.

[Einar Thorsrud]

How often do you see this issue? Do you do anything particular to trigger it?

[Ars Morozov]

Always when I connect through this device. I will try to connect from different iPhones and Androids to collect more statistic. I will write about it here..

[Spirit]

@Einar Thorsrud
5 times in 4 days. And in my case it is not related to the brand of the phone.
No, I don't It is completly random so why I can't debug it

[Einar Thorsrud]

In your case, this might be simply that you have deleted the bonding information on the nRF side but not on the phone side? The error message indicate so (4102 = 0x1006 = PM_CONN_SEC_ERROR_PIN_OR_KEY_MISSING). This issue should be fixed by simply removing the bond on the phone as well.

[Ars Morozov]

Thank you very much!

[Bugo]

To give further instructions about this since this helped me with my iPhone, "removing the bond" in my case meant going to Settings => Bluetooth, and looking for my nRF Device. Then go to "Forget this device". I also turned off Bluetooth afterwards just in case and re-enabled it. That Connection Security Failed message went away. Maybe just "Forgetting the device" is enough, haven't tried it.