RE: NRF52 NUS central could not receive message from peripheral after peering succeed in first time

Kenneth — Mon, 27 Apr 2020 11:12:29 GMT

Very likely you have set security on the characteristic, such that it's only after a bond has been established and link is secured that you are allowed to enable (write to) CCCD.

Best regards,
kenneth

RE: NRF52 NUS central could not receive message from peripheral after peering succeed in first time

Small_Bubble — Mon, 27 Apr 2020 05:57:37 GMT

Hi Nordic

after did some test, i found the issue was coming from the function "err_code = ble_nus_c_tx_notif_enable(&m_ble_nus_c);"

in the very beginning, this function is in event "BLE_NUS_C_EVT_DISCOVERY_COMPLETE"

   case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
	            NRF_LOG_INFO("Discovery complete.");
	            err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
	            APP_ERROR_CHECK(err_code);

	            /////////Added for bonding//////// 
	            err_code = pm_conn_secure(p_ble_nus_evt->conn_handle, false);
	            if (err_code != NRF_ERROR_BUSY)
	            {
	                APP_ERROR_CHECK(err_code);
	            }
	            /////////Added for bonding////////
	          /*
	            err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
	            APP_ERROR_CHECK(err_code);
	            */
	            NRF_LOG_INFO("Connected to device with Nordic UART Service.");
            break;

after i move "ble_nus_c_tx_notif_enable" to PM_EVT_CONN_SEC_SUCCEEDED. this issue has been fix up

    case PM_EVT_CONN_SEC_SUCCEEDED:
             NRF_LOG_INFO("pairing succeed.");
             err_code = pm_peer_id_get(m_ble_nus_c.conn_handle, &m_peer_to_be_deleted);
              APP_ERROR_CHECK(err_code);
              err_code = ble_nus_c_tx_notif_enable(&m_ble_nus_c);
              APP_ERROR_CHECK(err_code);    
            break;

May i know the reason for this ?