RE: BLE Advertising

Cyril Praz — Wed, 04 Jun 2025 15:16:44 GMT

For BLE 5.x:

You can maybe also used periodic advertising which may be more suitable for your use case.

Hope you are going well by the way. 😛

RE: BLE Advertising

tesc — Thu, 22 May 2025 14:29:20 GMT

Hi,

Thanks for letting us know. I have changed the tag from nRF5 SDK to nRF Connect SDK.

Regards,
Terje

RE: BLE Advertising

tesc — Thu, 22 May 2025 14:28:42 GMT

Hi,

Legacy Advertise (BLE 4.x):

[quote user=""]As far as I understand, when sending some specific data via the legacy advertise, those information are transmitted once on all three channels with a given delay in between them.[/quote]

Yes. The default is for each advertising event, to send the advertisement once on each advertising channel, with a small delay in-between.

[quote user=""]The TX power for the advertise packet is configurable. Now I'm wondering if it is possible to send it only on one channel[/quote]

No. The channel map cannot be configured for advertisement. I.e., advertising events will send on all three advertising channels,

[quote user=""]and if sending on multiple channels, if I can regulate the delay between two packets?[/quote]

No. The delay is fixed between the three packets of the same advertising event, and depend on the capabilities of the hardware. For seeing the stand by time (and for the nRF52 series also radio startup time) required in-between packet transmissions, you may have a look at the graphs provided by the Online Power Profiler for Bluetooth LE, selecting the device for which you want to know the values for.

[quote user=""]What about automatic retransmit (similar as the BT Mesh stack is doing it)?[/quote]

If you mean repeated transmissions of the same advertising payload, then yes. This is actually the default way of doing advertising in BLE. You set up your advertising data, and start advertising, which will go on for multiple advertising intervals using the same advertising data.

Extended Advertise (BLE 5.x):

[quote user=""]Also here my question, can I modify the delay when the data is transmitted?[/quote]

The delay after having transmitted on the three advertising channels, before transmitting over the secondary channel? I don't think so, at least it doesn't look like there are any configurations for that, no.

[quote user=""]Is there a possibility to automatic resend the adv?[/quote]

For extended advertising, as with normal legacy advertising, you can send the same payload repeatedly, yes. There seems to even be part of the API to configure the duration and number of advertising events: Zephyr API: bt_le_ext_adv_start_param Struct Reference

Regards,
Terje

RE: BLE Advertising

thischier — Wed, 21 May 2025 13:59:41 GMT

Sorry, wrong choice. I'm looking for information for the nRF Connect SDK