Windows 10 pairing issue.

[Ranajyoti Chakraborti]

I am using the latest SDK 15.2 example of ble_app_hrs as a template for my code, modified it but by an large the initialization code is the same. When I try to pair it with Windows 10 right after the MTU exchange it fails to pair. Bonding is turned off with the following settngs. But when I use nRF Connect from a adnroid device it pairs perfectly without any issue. Attachedare screenshots. Please advice.

Here is the log from the RTT viewer

0> <info> app: Connected.
0> <info> app: GATT ATT MTU on connection 0x0 changed to 247.
0> <info> app: Fast advertising.
0> <info> app: Disconnected, reason 19.

#define SEC_PARAM_BOND                      0                                      /**< Perform bonding. */
#define SEC_PARAM_MITM                      0                                       /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC                      0                                       /**< LE Secure Connections enabled. */
#define SEC_PARAM_KEYPRESS                  0                                       /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES           BLE_GAP_IO_CAPS_NONE                    /**< No I/O capabilities. */
#define SEC_PARAM_OOB                       0                                       /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE              7                                       /**< Minimum encryption key size. */
#define SEC_PARAM_MAX_KEY_SIZE              16                                      /**< Maximum encryption key size. */

[Ranajyoti Chakraborti]

Just to let you know I had to implement the following event like this to resolve the issue. This seems to be unique with windows.

case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
    NRF_LOG_INFO("BLE_GAP_EVT_SEC_PARAMS_REQUEST");
    err_code = sd_ble_gap_sec_params_reply(p_ble_evt->evt.gap_evt.conn_handle,
    									   BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP,
    									   NULL,
    									   NULL);
    APP_ERROR_CHECK(err_code);

[Ranajyoti Chakraborti]

Just one followup question. I am trying to do just bonding when I receive the BLE_GAP_EVT_SEC_PARAMS_REQUEST event as described in the sequence chart in this link https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.s140.api.v6.0.0%2Fgroup___b_l_e___g_a_t_t_s___f_u_n_c_t_i_o_n_s.html unfortunately I always get NRF_ERROR_INVALID_PARAM. Not really sure what I am doing wrong here.

NRF_LOG_INFO("BLE_GAP_EVT_SEC_PARAMS_REQUEST");
memset(&m_sec_keyset, 0, sizeof(ble_gap_sec_keyset_t));
err_code = sd_ble_gap_sec_params_reply(p_ble_evt->evt.gap_evt.conn_handle,
									   BLE_GAP_SEC_STATUS_SUCCESS,
									   &m_sec_param,
									   &m_sec_keyset);

[Kenneth]

Thanks for the update.

I know Win 10 by default always will try to encrypt the link after connection, while that is not the case for other OS that I am aware of. Typically other OS will first discover services and then only encrypt the link if any of the services require security.