LE privacy with timeslot API

[TAR CHAL]

Hi,

i want to know if there is a solution to apply LE privacy to a timeslot advertisement ?, my problem is : 

i have multiple advertisements at the same time (sofdevice + timeslot), each one on different MAC adress, i want to apply LE privacy to my

application in purpose to have the rotation of the MAC adresses, so, with softdevice no problem i adjust the ble_gap_privacy_params_t to

have a rotation each 10 minutes and it works, but with softdevice there is only one MAC adress and it didn't change, and even when i reboot 

the PDK the adress of softdevice changes but those with timeslot don't !!

Any one have an idea how to apply LE privacy to timeslot advertisement?

thanks,

regards  

[tesc]

Hi,

When using timeslots you essentially have to "do everything yourself" for implementing the BLE stack. Are you using a library for the timeslot advertising, and if so what library? You might for instance find either a struct of some sort or an uint8_t array named "ble_addr" or similar, holding the on-air address.

Regards,
Terje

 

[TAR CHAL]

Hi,

No, i'am not using a library, my starting point was multiactivity beacon example in SDK11, then  yes, i know that the ble_addr is in BLE PDU, what i mean is if there is a way to change this value automatically and periodically and not by setting it just like LE privacy do ? (and avoid that the same adresses are transmitted).

thanks,

[tesc]

Hi,

The multiactivity beacon example in SDK 11 has its advertising implementation in advertiser_beacon_timeslot.c. Unfortunately there is no built-in privacy feature in that implementation. (It is a simple implementation using static address only.) This means you must either implement that yourself, by adding address changing behavior, or use the SoftDevice instead.

I see that you have tagged the question with nRF52840, for which you would need a newer SDK. I recommend using the newest SDK (currently 14.2). If you use an nRF51 series SoC then I recommend SDK 12.3 which is the latest release supporting nRF51.

Some of the use cases previously requiring timeslot advertising can now be done with a SoftDevice (s130, s132 and s140), although for multiple advertisers it is still not straightforward. In any case you may have a look at using the SoftDevice for both advertisements, i.e. set address and advdata for #1, advertise for #1, stop advertising, set address and advdata for #2, advertise for #2, stop advertising, repeat.

If you go for a timeslot solution then you will not be using the SoftDevice (which is qualified with Bluetooth SIG) which means you may have to qualify your custom advertiser yourself.

Regards,
Terje