How to change the BLE mac address of NRF5430 at Real Time with NCS SDK?

[John]

  I follow below thread and refer to sample code and  the BLE mac address can be changed after system just boot up.

   devzone.nordicsemi.com/.../325131

   But after boot up, I want to change  the BLE mac address again, it doesn't work and the ble MAC address keep unchanged, it is expected?  Is it possible to change the desired BLE mac address at real time without HW reset?

Below is my Sudo code:

nrf5340 boot up,  

bt_enable(NULL);

bt_addr_t addr = {{0xFE, 0xCA, 0xA0, 0xAC, 0xDC, 0xBA}};
ble_set_mac(&addr);

settings_load();

ble_advertise();  //it works with ble addr = {{0xFE, 0xCA, 0xA0, 0xAC, 0xDC, 0xBA}}

ble_Stop_advertise();

bt_addr_t addr = {{0xFE, 0xCA, 0xA0, 0xAC, 0xDC, 0xBB}};
ble_set_mac(&addr);

settings_load();

ble_advertise(); //it doesn't work, ble address cant be changed.

found the ble's mac address is still  = {{0xFE, 0xCA, 0xA0, 0xAC, 0xDC, 0xBA}};

[Hieu]

Hi John,

Could you please refer to these tickets on the same topic?

https://devzone.nordicsemi.com/f/nordic-q-a/90889/how-to-set-static-nrf52-mac-address-in-using-nrf-connect-sdk-2-0-0
https://devzone.nordicsemi.com/f/nordic-q-a/92583/setting-nrf5340-public-ble-address

Hieu

P.s: Please note that it is the summer holiday season here. We are thus understaffed and there would be delay in responses. Our apologies for the inconveniences.

[John]

Hi Hieu,

  For my case, NRF5430 is used. so  bt_setup_public_id_addr() doesn't work, becasue cmd  bt_setup_public_id_addr() cann't be issued directly at the applicaion core side.

 I can use ble_set_mac() ---> bt_hci_cmd_send_sync() cmd to change the mac address successffully, but It only can be chnage once after  NRF5430 power on. It is expected or any solution to solve it?

[Karl Ylvisaker]

Hello John,

Do you need to change the address to a specific other address, or just to change it at all (like the privacy feature)?
In case of the latter you could use the sdc_hci_cmd_le_set_random_address function to achieve this.

Or, is your intention to go between 2 specific mac addresses, for instance?

Best regards,
Karl

[John]

Hi Karl, I need to change to specific other address.

[AHaug]

Hi, 

I'm handling the case for Karl while he's out of office.

To change the address to a specific address you can use section 4.2 in this exercise from the BLE course on our academy pages: https://academy.nordicsemi.com/topic/blefund-lesson-2-exercise-3/ 

Let me know if this answers your questions

Kind regards,
Andreas