RE: Correct configuration for secure connections pairing

WeBBK — Wed, 16 Jul 2025 17:57:43 GMT

hi Amanda,

The issue is fixed by the reference example link you provided.

thanks.

RE: Correct configuration for secure connections pairing

Amanda Hsieh — Tue, 15 Jul 2025 13:00:49 GMT

Do you see the same issue while testing with a mobile phone? If not, comparing the sinffer logs of them to find the differences.

RE: Correct configuration for secure connections pairing

WeBBK — Fri, 11 Jul 2025 08:50:55 GMT

If I switch sec_param.io_caps to BLE_GAP_IO_CAPS_DISPLAY_ONLY, it allows the central device (BlueZ) to correctly prompt for passkey input, as shown below.

However, the peripheral (nRF52840-DK) does not trigger the BLE_GAP_EVT_AUTH_KEY_REQUEST event for unknown reasons. As a result, the defined passkey cannot be used, and pairing fails (Central keeps requesting input repeatedly).

case BLE_GAP_EVT_AUTH_KEY_REQUEST:
        {
            NRF_LOG_INFO("BLE_GAP_EVT_AUTH_KEY_REQUEST");
             
            err_code = sd_ble_gap_auth_key_reply(p_ble_evt->evt.gap_evt.conn_handle,
                                                 BLE_GAP_AUTH_KEY_TYPE_PASSKEY,
                                                  (uint8_t *)"123456"); // Fixed 6-digit passkey
            APP_ERROR_CHECK(err_code);
        } break;

00> <info> app: Fast advertising.
00> 
00> <info> app: Disconnected, reason 19.
00> 
00> <info> app: Connected.
00> 
00> <info> app: GATT ATT MTU on connection 0x0 changed to 247.
00> 
00> <info> app: GATT ATT MTU on connection 0x0 changed to 247.
00> 
00> <info> peer_manager_handler: Connection security failed: role: Peripheral, conn_handle: 0x0, procedure: Bonding, error: 1
00> 
00> <warning> app: Security failed. conn_handle: 0x0, error: 0x1
00> 
00> <info> app: BLE_GAP_EVT_AUTH_STATUS: status=0x1 bond=0x0 lv4: 0 kdist_own:0x0 kdist_peer:0x0

Do you have any suggestions for resolving this issue?

RE: Correct configuration for secure connections pairing

Amanda Hsieh — Thu, 10 Jul 2025 20:32:28 GMT

Hi,

Take a look at the example in this post and test with a phone. Not sure if the issue is on your central device (BlueZ) or not.

Regards,
Amanda H.