Implementing a bonding mode

[jbroxson]

Device:

• Peripheral only
• Peer Manager and Bonding working
• S140 radio
• nRF5 SDK 15.2.0
• Rigado BMD-340 module
• Central == iOS devices

Our nRF5 module is controlled by a Kinetis which uses a GPIO to indicate it should boot into a "bonding mode".  In this mode, it should advertise to any device with power at -40. (This is working). When not in bonding mode, we want the device to advertise only to bonded devices (and do this at +8 power).  The idea is that bonding should occur in close proximity only, and only bonded devices can connect when in non-bonding mode at higher power (allowing connection at a larger distance).

I have been trying to accomplish this through various means such as whitelist.  This is implemented and works, but I can not stop it from doing some other sort of advertising (fast/slow). If I configure advertising to only do whitelist, the API returns an error (don't have it handy, but was along the lines of "incorrect parameter").

My testing for this involved adding the HRM guid to our advertising data, which allows it to appear in the iOS Bluetooth browse list. (Our device normally advertises BAS, DI, and a custom service - which won't show up in the normal "device browser", can only be discovered using APIs in our iOS app.)

Code for our advertising init is below. In this code I tried setting fast/slow to low timeouts, but iOS still sees it.  Any suggestions on how to make this work properly, or a different approach?

memset(&init, 0, sizeof(init));     init.evt_handler                                = on_adv_evt;     init.error_handler                              = ble_advertising_error_handler;     init.advdata.name_type                          = BLE_ADVDATA_FULL_NAME;     init.advdata.include_appearance                 = true;     init.advdata.flags                              = BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE;     init.srdata.uuids_complete.uuid_cnt             = sizeof(s_adv_uuids) / sizeof(s_adv_uuids[0]);     init.srdata.uuids_complete.p_uuids              = s_adv_uuids;     init.config.ble_adv_on_disconnect_disabled      = false;     if (nrf_gpio_pin_read(PIN_BOND))     {         init.config.ble_adv_fast_enabled            = true;         init.config.ble_adv_fast_interval           = APP_ADV_FAST_INTERVAL;         init.config.ble_adv_fast_timeout            = APP_ADV_FAST_DURATION;         init.config.ble_adv_slow_enabled            = true;         init.config.ble_adv_slow_interval           = APP_ADV_SLOW_INTERVAL;         init.config.ble_adv_slow_timeout            = APP_ADV_SLOW_DURATION;         init.config.ble_adv_whitelist_enabled       = false;     }     else     {         init.config.ble_adv_directed_high_duty_enabled = true;         init.config.ble_adv_directed_enabled        = true;         init.config.ble_adv_directed_interval       = APP_ADV_FAST_INTERVAL;         init.config.ble_adv_directed_timeout        = APP_ADV_FAST_DURATION;         init.config.ble_adv_whitelist_enabled       = true;         init.config.ble_adv_fast_enabled            = true;         init.config.ble_adv_fast_interval           = 40;         init.config.ble_adv_fast_timeout            = 100;         init.config.ble_adv_slow_enabled            = true;         init.config.ble_adv_slow_interval           = 1600;         init.config.ble_adv_slow_timeout            = 100;     }     err_code = ble_advertising_init(&s_advertising, &init);     APP_ERROR_CHECK(err_code);     ble_advertising_conn_cfg_tag_set(&s_advertising, APP_BLE_CONN_CFG_TAG);

Thanks!

[Joakim Jakobsen]

Hi! 

The idea is that bonding should occur in close proximity only, and only bonded devices can connect when in non-bonding mode at higher power (allowing connection at a larger distance).

Code for our advertising init is below. In this code I tried setting fast/slow to low timeouts, but iOS still sees it.

What do you mean iOS still sees it? 
When you say that "only bonded devices can connect when in non-bonding mode", do you want the device advertising to be invisible to non-bonded devices?

If I configure advertising to only do whitelist, the API returns an error (don't have it handy, but was along the lines of "incorrect parameter")

 Could you try debugging your application again, and try figure out where exactly you are getting the invalid parameter error from?

Best regards

[jbroxson]

Joakim,

Changing the code so that it only enables whitelist and directed advertising results in an error 7 from ble_advertising_init.

    if (nrf_gpio_pin_read(PIN_BOND))
    {
        init.config.ble_adv_fast_enabled            = true;
        init.config.ble_adv_fast_interval           = APP_ADV_FAST_INTERVAL;
        init.config.ble_adv_fast_timeout            = APP_ADV_FAST_DURATION;

        init.config.ble_adv_slow_enabled            = true;
        init.config.ble_adv_slow_interval           = APP_ADV_SLOW_INTERVAL;
        init.config.ble_adv_slow_timeout            = APP_ADV_SLOW_DURATION;

        init.config.ble_adv_whitelist_enabled       = false;
    }
    else
    {
        init.config.ble_adv_directed_high_duty_enabled = true;
        init.config.ble_adv_directed_enabled        = true;
        init.config.ble_adv_directed_interval       = APP_ADV_FAST_INTERVAL;
        init.config.ble_adv_directed_timeout        = APP_ADV_FAST_DURATION;

        init.config.ble_adv_whitelist_enabled       = true;
///////// only enable whitelist and directed in this case
//        init.config.ble_adv_fast_enabled            = true;
//        init.config.ble_adv_fast_interval           = 40;
//        init.config.ble_adv_fast_timeout            = 100;

//        init.config.ble_adv_slow_enabled            = true;
//        init.config.ble_adv_slow_interval           = 1600;
//        init.config.ble_adv_slow_timeout            = 100;

    }

    err_code = ble_advertising_init(&s_advertising, &init);
    APP_ERROR_CHECK(err_code);//// <<<  Error 7 (NRF_ERROR_INVALID_PARAM) hit here

If I enter bluetooth settings on iOS, remove any bonding to the nRF device, reboot the iOS device (iOS does some caching which can cause weirdness at times), then browse for it, I can see the device if FAST or SLOW advertising is enabled (expected). I am not able advertise without FAST or SLOW enabled (the error 7 above will occur).

Thanks!

[Joakim Jakobsen]

Hi again!

Sorry about the long delay here. 

Have you made any progress on this?

So you are getting error 7 (Invalid param) when you aren't using the APP_ADV_FAST_INTERVAL with the directed advertising?

What did you try to set the interval to when you got the error?

Best regards, 
Joakim

[Joakim Jakobsen]

Sorry I think I misread the question. 

You are getting the error 7 when slow/fast advertising is not enabled? So you are only getting the error using directed advertising?

[jbroxson]

Yes. That is correct. I understand why that is not valid, but our goal is to allow only directed or whitelist when in our Connectable mode, while allowing normal (fast/slow) in our Bonding mode. How can I prevent the device from entering Fast and Slow advertising (without whitelist) after the whitelist modes timeout?

Thanks