RE: Unable to start 2 periodic advertisers on nrf54L15

Gilles Boccon-Gibod — Mon, 29 Dec 2025 19:41:55 GMT

Setting `CONFIG_BT_EXT_ADV_MAX_ADV_SET=2` does indeed fix the issue.

It is somewhat confusing, because I have `CONFIG_BT_CTLR_ADV_SET=3`, which is supposed to be the limit at the controller level, and indeed, the controller returns 3 when queried with `LE_READ_NUMBER_OF_SUPPORTED_ADVERTISING_SETS_COMMAND`, but somehow `CONFIG_BT_EXT_ADV_MAX_ADV_SET` applies a further restriction, which can't be queried with HCI commands (and that I assumed applied only to the host stack, not the controller).

RE: Unable to start 2 periodic advertisers on nrf54L15

Kenneth — Mon, 29 Dec 2025 12:31:12 GMT

Hello,

I am not aware of any specific limit, but I can ask internally. In the meantime you can check that you have configured more than 1 advertising, e.g. look at:
https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/samples/bluetooth/peripheral_with_multiple_identities/README.html#number_of_advertisers

From the source documentation I can find \nrfxlib\softdevice_controller\include\sdc_hci_cmd_le.h :

* If the Advertising_Handle does not identify an advertising set that is already configured

* for periodic advertising and the Controller is unable to support more periodic advertising

* at present, the Controller shall return the error code Memory Capacity Exceeded (0x07).

Kenneth