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
<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.
I managed to reproduce the issue and have reported this internally. I will update this case when we find the cause of this issue.
Hello Mttrinh, I was wondering if you have any update for me.
I don't have any update on this matter for now, but in your case have you tried testing with other iphones to see if it makes any difference? I do manage to reproduce it but it isn't often like you see it. Also, it is working despite the error message, the security will retry until it succeed.
Yes, it's almost the same with another iPhone. Although it eventually succeeds, but I need to quickly establish a connection when the user comes to the office and before he/she arrives to the desk. This issue sometimes imposes a long delay and I am not able to reach the design goal.
would appreciate to let me know whenever there's an update.
May I ask the root cause of this issue (if you have found it)?