How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Tue, 28 Apr 2020 09:50:47 GMT

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/185800"] I changed the priority to allow the app to stop the non-connectable advertising before the event gets processed by the advertisement module[/quote]

Revisiting to allow multiple connections, this seems to break the Connection State module.

😞

See: https://devzone.nordicsemi.com/f/nordic-q-a/60788/ble_observer_prio---priorities-with-advertising-and-the-connection-state-module

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Mon, 20 May 2019 17:43:31 GMT

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187267"]On Android 8.0, there is no 'Connect' button for the Non-Scannable, Non-Connectable advertising[/quote]

Actually, that's not quite true.

It seems that nRF Connect is just not very good at keeping that button in-sync with the type of advertising!

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Vidar Berg — Mon, 20 May 2019 08:25:03 GMT

I was not aware of this bug, thanks for pointing it out. Anyway, the main purpose of this demo was to show how you can use the "update" API.

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187586"]Is this just an artefact of having the RTT logger attached?[/quote]

I forgot to disable timeout for the non-connectable advertisement, that's why sleep_mode_enter() got called.

sd_power_system_off() will return with an error when the chip is in debug interface mode, see emulated system OFF mode: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/power.html?cp=3_1_0_17_1_0#unique_1199040052

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Thu, 16 May 2019 17:28:00 GMT

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187574"]Just remove the code below from update_advertising_data() if you want the data to be updated while connected[/quote]

Actually, that code means that the Advertising Data is never updated after the first connection!

This is due to a bug in the original Template code - which never clears m_conn_handle after a connection!

We need to add it on the BLE_GAP_EVT_DISCONNECTED event:

/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t err_code = NRF_SUCCESS;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.");

            m_conn_handle = BLE_CONN_HANDLE_INVALID;   //  <<<<<  HERE !

            // LED indication will be changed when advertising starts.

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Thu, 16 May 2019 16:56:33 GMT

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187574"]Please review and test the example I uploaded in my previous comment[/quote]

I connected & disconnected, then left it connected for a while.

When I came back, this had happened:

<info> app: 8816 Template example with non-connectable advertising while connected.
<info> app: Fast advertising.
<info> app: Connected.
<info> app: Disconnected.
<info> app: Fast advertising.
<info> app: Connected.
<error> app: ERROR 8198 [Unknown error code] at main.c:478
PC at: 0x0002F33B
<error> app: End of error report

Line 478 is the APP_ERROR_CHECK at the end of sleep_mode_enter():

    // Go to system-off mode (this function will not return; wakeup will cause a reset).
    err_code = sd_power_system_off();
    APP_ERROR_CHECK(err_code);

The code is unmodified, apart from the name displayed in the startup log.

EDIT

And again - this time while advertising:

:
:
:
<info> app: Fast advertising.
<info> app: Connected.
<info> app: Disconnected.
<info> app: Fast advertising.
<error> app: ERROR 8198 [Unknown error code] at main.c:478
PC at: 0x0002F33B
<error> app: End of error report

Is this just an artefact of having the RTT logger attached?

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Thu, 16 May 2019 15:45:15 GMT

I had separately tried to do it without adjusting priorities:

https://devzone.nordicsemi.com/f/nordic-q-a/47391/sdk-15-3-0-restart-non-connectable-advertising-after-timeout

But that has its own issues!

Will have a look at your latest ...

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Vidar Berg — Thu, 16 May 2019 15:31:43 GMT

Please review and test the example I uploaded in my previous comment. Just remove the code below from update_advertising_data() if you want the data to be updated while connected.

    /* In this demo we update advertising while we're disconnected*/
    if (m_conn_handle != BLE_CONN_HANDLE_INVALID)
    { 
        return;
    }

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Thu, 16 May 2019 14:52:15 GMT

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187435"]update advertising data while disconnected[/quote]

It needs to keep updating the advertising data at all times - not just while disconnected.

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187435"]It works, but we should have made it more clear[/quote]

It could hardly be less clear!

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187435"]Note the last line. [/quote]

It remains as clear as mud!

Please update that thread with a complete example.

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187435"]Are you not getting BLE_GAP_EVT_ADV_SET_TERMINATED event on timeout? [/quote]

No - no event at all.

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Vidar Berg — Thu, 16 May 2019 07:56:12 GMT

I've expanded the example above to update advertising data while disconnected. It's built with SDK v15.3.0. Please see attached below.

devzone.nordicsemi.com/.../8816.ble_5F00_app_5F00_template.zip

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187363"][/quote]

But, as previously noted, it does not work:

https://devzone.nordicsemi.com/f/nordic-q-a/41669/ble_advertising_advdata_update/183212#183212

It works, but we should have made it more clear that you need to provide a new buffer when you update the data.

Excerpt of the code comments for the ble_gap_adv_data_t struct:

/**@brief GAP advertising data buffers.
 *
 * The application must provide the buffers for advertisement. The memory shall reside in application RAM, and
 * shall never be modified while advertising. The data shall be kept alive until either:
 *  - @ref BLE_GAP_EVT_ADV_SET_TERMINATED is raised.
 *  - @ref BLE_GAP_EVT_CONNECTED is raised with @ref ble_gap_evt_connected_t::adv_handle set to the corresponding
 *    advertising handle.
 *  - Advertising is stopped.
 *  - Advertising data is changed.
 * To update advertising data while advertising, provide new buffers to @ref sd_ble_gap_adv_set_configure. */

Note the last line.

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187363"]But with Vidar Berg's code here, I no longer get the Advertising Timeout event![/quote]

Are you not getting BLE_GAP_EVT_ADV_SET_TERMINATED event on timeout?

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Wed, 15 May 2019 19:05:54 GMT

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/180421"]The advertisement module in SDK 15.3.0 includes an API for updating advertisement data on the fly[/quote]

But, as previously noted, it does not work:

https://devzone.nordicsemi.com/f/nordic-q-a/41669/ble_advertising_advdata_update/183212#183212

As a workaround in SDK 15.3.0, I use the Advertising Timeout and do the update there before re-starting advertising (which is similar to other suggestions):

https://devzone.nordicsemi.com/f/nordic-q-a/41669/ble_advertising_advdata_update/187065#187065

But with Vidar Berg's code here, I no longer get the Advertising Timeout event!

So what's going on with that?!

(the advertising is stopping after the specified duration)

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Wed, 15 May 2019 14:16:34 GMT

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/180421"]Here's my modified template project (SDK 15.0.0) [/quote]

It doesn't build with SDK 15.3.0.

I applied your changes to the main.c in the SDK 15.3.0 project, and that does work. The file is attached.

All the changes for non-connectable advertising are controlled by #if ADVERTISE_WHILE_CONNECTED

Note that you need to change NRF_LOG_DEFAULT_LEVEL from 3 to 4 in sdk_config.h in order to see the NRF_LOG_DEBUG messages.

The choice between Scannable & Non-scannable advertising is also on a #if - in non_connectable_advertising_start():

#if 0
    NRF_LOG_DEBUG( "Non-connectable, Scannable advertising" );
    adv_params.properties.type = BLE_GAP_ADV_TYPE_NONCONNECTABLE_SCANNABLE_UNDIRECTED;
#else
    NRF_LOG_DEBUG( "Non-connectable, Non-scannable advertising" );
    adv_params.properties.type = BLE_GAP_ADV_TYPE_NONCONNECTABLE_NONSCANNABLE_UNDIRECTED;
#endif

devzone.nordicsemi.com/.../453361.main.c

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Wed, 15 May 2019 12:31:22 GMT

On Android 8.0, there is no 'Connect' button for the Non-Scannable, Non-Connectable advertising.

On Android 6, the 'Connect' button is always there - Scannable on Non-scannable.

So it looks like there is a flaw in nRF Connect, too.

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Wed, 15 May 2019 12:16:39 GMT

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187238"]does the fact that it just says "Scannable" - mean that it is non-connectable?[/quote]

Aparently so:

If I change

adv_params.properties.type = BLE_GAP_ADV_TYPE_NONCONNECTABLE_SCANNABLE_UNDIRECTED;

adv_params.properties.type = BLE_GAP_ADV_TYPE_NONCONNECTABLE_NONSCANNABLE_UNDIRECTED;

Then nRF Connect Desktop does, indeed, say:

Address type: RandomStatic

Advertising type: Non connectable undirected

Services: Device Information

Flags: LeGeneralDiscMode

BrEdrNotSupported

LeOnlyLimitedDiscMode

LeOnlyGeneralDiscMode

Appearance:00-00

But it will still try to connect!

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Wed, 15 May 2019 12:01:12 GMT

[quote userid="4240" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/187118"]It appears to be an Android limitation[/quote]

'#~$£%%~##@@ !!

😞

But the article goes on to say:

"The problem is on devices prior to Anroid 8.0"

My phone is Android 8.0 - and I still don't see it.

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Wed, 15 May 2019 11:55:40 GMT

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/186788"]With nRF Connect on Android, I can still see advertising when it's connected to another device - but there is nothing to indicate that it's non-connectable advertising[/quote]

With nRF Connect Desktop v2.6.2 on Windows I see:

"Fast Advertising":

Address type: RandomStatic
Advertising type: Connectable undirected
Services: Device Information
Flags: LeGeneralDiscMode
BrEdrNotSupported
LeOnlyLimitedDiscMode
LeOnlyGeneralDiscMode
Appearance:00-00

"Non-connectable advertising":

Address type: RandomStatic
Advertising type: Scannable undirected
Services: Device Information
Flags: LeGeneralDiscMode
BrEdrNotSupported
LeOnlyLimitedDiscMode
LeOnlyGeneralDiscMode
Appearance:00-00

So does the fact that it just says "Scannable" - mean that it is non-connectable?

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/186788"]if I press the 'Connect' button, nRF Connect will try to connect[/quote]

Same on Desktop!

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Wed, 15 May 2019 11:48:39 GMT

v15.3.0

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Vidar Berg — Wed, 15 May 2019 06:14:39 GMT

which SDK version are you using?

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Vidar Berg — Wed, 15 May 2019 06:14:14 GMT

It appears to be an Android limitation: https://stackoverflow.com/questions/28467590/detecting-whether-a-ble-device-is-connectable-on-android. It shows up as non-connectable on my iPhone.

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Tue, 14 May 2019 16:20:46 GMT

But it doesn't work:

https://devzone.nordicsemi.com/f/nordic-q-a/41669/ble_advertising_advdata_update/183212#183212

😞

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Tue, 14 May 2019 10:43:35 GMT

[quote userid="6462" url="~/f/nordic-q-a/45644/how-do-i-simply-do-a-non-connectable-advert-on-nrf52-using-sdk-15/186788"] I press the 'Connect' button, nRF Connect will try to connect[/quote]

Like Michael McClary at CloudLeaf in the OP, my reason for doing this is so that other Centrals can still see that it's there when it's connected - so it doesn't just "disappear" - but they should know it's "busy" and, therefore, not connectable.

So is nRF Connect just being dumb in trying to connect?

Or is the advertising not actually "non-connectable"?

Or is there some Android limitation which means that apps can't tell whether advertising is "connectable" or not?

Or what??

Vidar Berg

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Mon, 13 May 2019 19:07:06 GMT

So how do we tell that it's actually working?

Specifically, how do we tell that it's doing non-connectable advertising?

With nRF Connect on Android, I can still see advertising when it's connected to another device - but there is nothing to indicate that it's non-connectable advertising.

In fact, if I press the 'Connect' button, nRF Connect will try to connect.

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Vidar Berg — Tue, 07 May 2019 16:14:59 GMT

awneil, sorry, I see now that this comment wasn't particularly helpful. The advertisement module will start connectable advertising on BLE_GAP_EVT_DISCONNECT. So I changed the priority to allow the app to stop the non-connectable advertising before the event gets processed by the advertisement module.

Adv. stop in main.c->ble_evt_handler():

static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    ret_code_t err_code = NRF_SUCCESS;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Disconnected.");
            // LED indication will be changed when advertising starts.

              /*Stop advertising to allow the advertising module to start 
                connectable advertising. It's not possible to change adv. params 
                on the fly, only data*/
            (void)sd_ble_gap_adv_stop(m_advertising.adv_handle);
            break;

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

awneil — Mon, 06 May 2019 11:33:17 GMT

In that example, could you explain this:

/*Application needs higher priority than BLE_ADV_BLE_OBSERVER_PRIO in this case */
#define APP_BLE_OBSERVER_PRIO           0                                       /**< Application's BLE observer priority. You shouldn't need to modify this value. */

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Michael McClary at CloudLeaf — Sun, 07 Apr 2019 00:47:24 GMT

Thank you.

With that for an example I was able to

get the template doing connected advertising correctly (on our board) with the basic SDK 15.0
get the template do it with all our SDK tweaks
get the actual project to do it corretly.

Excellent!

RE: How do I (simply) do a non-connectable advert on nRF52 using SDK 15?

Vidar Berg — Fri, 05 Apr 2019 07:29:33 GMT

Hi,

[quote user="mcclary"]I notice that, after disconnect, ble_advertising.c seems to spend some time doing directed advertising [/quote]

This is optional. The template example only enables fast mode in advertising_init(). init.config.ble_adv_directed_enabled is initialized to '0' by default.

[quote user=""](I WILL be needing on-the-fly adjustment of the manufacturing field in another month or so, so info on that would also be nice. But I need the above right away.)[/quote]

The advertisement module in SDK 15.3.0 includes an API for updating advertisement data on the fly. I think it should be easy to backport.

Here's my modified template project (SDK 15.0.0) which starts non-connectable advertising during connections:

devzone.nordicsemi.com/.../ble_5F00_app_5F00_template.zip