Advertising doesn't after calling sd_ble_gap_adv_start

[Fabian Hauschild]

Hi everybody,

I'm having a problem with the advertising function of the SoftDevice.

When the application starts advertising the function "sd_ble_gap_adv_start()" returns without an error.

But it takes up to 10 seconds until I can see the advertising with the nRF Connect App.

How can I fix this?

I'm using

Laird BL654 (nRF 52840)

SDK16

SD140v7.0.1

I have asked a similar question before but this question seems to be closed

https://devzone.nordicsemi.com/f/nordic-q-a/54839/advertising-doesn-t-start-immediately-after-calling-sd_ble_gap_adv_start

Best regards Fabian

[Einar Thorsrud]

Hi Fabian,

Assuming that everything works and the nRF is advertising in connectable mode form the start, the time it takes until a connection is established depends mainly on the following factors:

• Advertising interval on the peripheral
• Scan duty cycle (window and interval) on the central

Looking at the old thread, it looks like advertising does not start immediately? If so, that is the first thing you need to check. How long does it take before you call sd_ble_gap_adv_start()? Have you checked with a sniffer? When does the peer try to connect? Is the problem that there are unsuccessful connect requests for some reasons? (just a shot in the dark) A sniffer trace should shed some light on this.

[Fabian Hauschild]

Hi Einar,

thanks for the fast answer.

sd_ble_gap_adv_start() returns without an error but it takes upto 10 seconds until I can se the advertising with the nRF connect app.

I think I forgot to mention that there is also a BLE Mesh stack running

sd_ble_gap_adv_start() is called after everithing is inialized (might take upto 1 s after power up) .

I could use a nRF Sniffer, if that is OK I will provide you with the sniffer data

There iseems to no problems with connectiong to the peer.

[Einar Thorsrud]

Fabian Hauschild said:

I think I forgot to mention that there is also a BLE Mesh stack running

 That may be relevant. I assume it is the Nordic BLE Mesh stack? Can you provide more details on your application and config? Depending on the configuration, it might be that the mesh stack uses a lot of time (for scanning in particular), leaving less time for the normal advertiser.

[Fabian Hauschild]

Hi Einar,

yes I'm using the Nordic BLE Mesh Stack. 

When I disable the Mesh Stack then Advertising starts immeadiatly .

I'm using SDK version 16.0.0 and SDK for Mesh version 3.0.0. 

At the time I'm using the mesh stack to receive data from EnOcean  switches but we are planing to add mesh functionallity to this product in the future.

I've used this example to integrade the mesh stack in an existing SDK project.

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.meshsdk.v3.0.0%2Fmd_doc_getting_started_how_to_nordicSDK.html&cp=7_6_2_1_10

[Einar Thorsrud]

I do not have an immediate explanation, but the combination of SDK version 16 and SDK for Mesh version 3 is not compatible. Can you test with SDK for Mesh 4? That is the only SDK for Mesh which supports SDK 16.

[Fabian Hauschild]

I tested with SDK for Mesh 4 yesterday and the problem is still the same.

I tried turning off the Mesh with nrf_mesh_disable() before starting advertising and truning mesh back on with nrf_mesh_enable() after advertising has started.

After this change the advertising starts immediately but the EnOcean switch isn't working anymore.