NUS example, authorize request, sd_ble_gatts_hvx

[Hauser]

Hi together,

I'm using the NUS example (NRF52832) for client and peripheral, which is running quite well. My goal is to inform the peripheral application when notification was enabled on central side. Thus I added the line cccd_md.wr_auth = 1; in the function rx_char_add and added

switch (p_ble_evt->header.evt_id)

{
    case BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST:
        {
            /* we get this event on peripheral side, when central enabled notifications */
            if(p_ble_evt->evt.gatts_evt.params.authorize_request.type == BLE_GATTS_AUTHORIZE_TYPE_WRITE)
            {
                /* reply with SUCCESS/ALLOWED */
                ble_gatts_rw_authorize_reply_params_t rw_authorize_reply_params;
                memset(&rw_authorize_reply_params, 0, sizeof(rw_authorize_reply_params));
                rw_authorize_reply_params.type = BLE_GATTS_AUTHORIZE_TYPE_WRITE;
                rw_authorize_reply_params.params.write.gatt_status = BLE_GATT_STATUS_SUCCESS;
                rw_authorize_reply_params.params.write.update = 1;
                err_code = sd_ble_gatts_rw_authorize_reply(m_ble_nus.conn_handle, &rw_authorize_reply_params);
                APP_ERROR_CHECK(err_code);

in the function on_ble_evt. With this, as soon the the function ble_nus_c_rx_notif_enable was called from central, the peripheral got a BLE_GATTS_EVT_RW_AUTHORIZE_REQUEST such that I was able to inform the application that the central has enabled notifications. The described code was running very well with softdevice S132 1.0.0-3-alpha and sdk 0.9.2.

Now I'm using S132 V2.0.0 and nRF5 SDK 11.0.0 and get the following error: After connection setup, when I want to send data to the central using ble_nus_string_send the function sd_ble_gatts_hvx returns 0x3401. This was not the case, when using the "old" softdevice. How can I solve this problem?

Is there another way to inform the peripheral when a central connected and discovered all services successfully?

Thank you!

[Hung Bui]

Hi Hauser,

You received 0x3401 = BLE_ERROR_GATTS_SYS_ATTR_MISSING because you haven't called sd_ble_gatts_sys_attr_set() to init the system attribute. Have you made sure you called that in BLE_GATTS_EVT_SYS_ATTR_MISSING even in on_ble_evt() ?

Also I don't really understand why do you need write with authorize request for this case. You can simply leave it as normal write, and catch the BLE_GATTS_EVT_WRITE even, and check for the handle ID of the CCCD characteristic. No need for authorized write here.

[Hauser]

Thank you! You are right, catching the BLE_GATTS_EVT_WRITE event does the job without any authorization workaround.