How can I use directed advertizing when my application reset or wake up from sd_power_system_off?

[pcc]

Hi, every one,

In my application , we need to bond my device with host , and then our application will go to deep sleep by calling sd_power_system_off. When I wake up my application by a wake up pin, how to do the directed advertizing when I had bonded my device with host successfully before?

[Susheel Nuguru]

You can use the ble_advertising module, look into the documentation here

You then you just use ble_advertising_start(BLE_ADV_MODE_DIRECTED);

and then implement the peer address fetch in your application ble_event handler as below

    case BLE_ADV_EVT_PEER_ADDR_REQUEST:
    {
        ble_gap_addr_t peer_address;

        // Only Give peer address if we have a handle to the bonded peer.
        if(m_bonded_peer_handle.appl_id != DM_INVALID_ID)
        {
                        
            err_code = dm_peer_addr_get(&m_bonded_peer_handle, &peer_address);
            APP_ERROR_CHECK(err_code);
        
            err_code = ble_advertising_peer_addr_reply(&peer_address);
            APP_ERROR_CHECK(err_code);
            
        }
        break;
    }

[pcc]

Thanks for your sharing, but are this API and event parts of SDK 7.2? Why I can't find this definition in SDK 7.2 source code?

[Susheel Nuguru]

i took it from SDK 8.0, thats what i assumed you were using. i am not sure if this is available in 7.2. If you are not using device manager (dm_xx functions) then how are you managing your bond information?

[Susheel Nuguru]

Im sorry, i just realized that ble_advertiser module does not exist in 7.2, I will find out how it is done in 7.2 and give you an answer soon

[Susheel Nuguru]

You can look into the ble_app_hids_keyboard example. There you can see that this application tries to do DIRECTED advertising once it got disconnection event. Particularly look into

ob_ble_evt()
        case BLE_GAP_EVT_DISCONNECTED:
            m_advertising_mode = BLE_DIRECTED_ADV;
            m_direct_adv_cnt   = APP_DIRECTED_ADV_TIMEOUT;

            advertising_start();
            break;

you can modify this to call as per your need.

[pcc]

Yes, I know this can do directed advertising, but in my description as above, our application will go to deep sleep by calling sd_power_system_off, after that, when our device wake up from deep sleep, the bonded handle had lost. So we can't go to the direct advertising successfully, and then the whitelist advertising will replace the directed advertising.