Connection security failed: role: Central in ble_app_rscs_c

[HSh]

Hello,

I am working on nRF52840 DK with nRF5_SDK_15.2.0_9412b96 and I used the example ble_app_rscs_c with absolutely no changes. I first erased the flash and then burned the Softdevice and app to erase any bonding. I used LightBlue on my iPhone to advertise 0x1814 (BLE_UUID_RUNNING_SPEED_AND_CADENCE). The first time I received the pairing request on iPhone. Every time I restart the DK, I receive the following error several times (4 to 5 times):

<info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Encryption, error: 4352

and then

<info> peer_manager_handler: Connection secured: role: Central, conn_handle: 0, procedure: Encryption.

Although it finally works, these failures cause a long delay.  I have also seen this problem reported for BLE peripheral examples but their solution (un-pairing from iPhone) does not work for me. I need to keep the devices paired.

I was wondering how I can fix this.

Thanks,

[BendaEng]

Hi, 

I was having this same issue. I was able to mitigate this through connecting to the Target (in SES with a development board Target -> Connect J-Link) and Erasing the board and re-flashing (Target -> Erase All). Then I re-flashed and ran my applications. My best guess is their is some corruption that occurs in RAM where the SoftDevice is located. Maybe this solution will work for you too. 

Thanks!

[HSh]

Hi, I did so and the problem is still there.