Disable address advertising.

[Yacire]

Hi All,

I have a basic question about advertsing data, more precisely about device's address. I try to disable in my advertising data, the address field but it doesn't work...

I do this like that:

uint32_t      err_code;
ble_advdata_t advdata;

memset(&advdata, 0, sizeof(advdata));

advdata.name_type          = BLE_ADVDATA_FULL_NAME;
advdata.include_appearance = true;
advdata.flags              = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;

err_code = ble_advdata_set(&advdata, NULL);
APP_ERROR_CHECK(err_code);

But when i scan with my smartphone my Ble device, i always see the address. I don't understand, beacause the field: bool include_ble_device_addr;

is equal to 0.So the advertising packet normally doesn't include the address...

I tested too with this line: advdata.include_ble_device_addr = true; But i have this error on nrfConnect app (Android):

Best regards.

[Jørgen Kvalvaag]

It is not possible to advertise without the BLE address, this would be a spec violation. The BLE address is part of the BLE packet header, the API you refer to (include_ble_device_addr) is spesifically for adding the address to the packet data.

If you don't want your device to be identifiable you can change the address to any value you like, using the softdevice API sd_ble_gap_address_set()

Documentation link

[Yacire]

Thanks a lot Jorgen,

But what is the purpose of adding the address to the packet_data during advertising, if it is already added to packet_header ? I don't understand why you added this possibility to do this in Nordic's SDK ?

Thansk.

[Jørgen Kvalvaag]

That is a good question indeed :)

The advertising data packet format is defined by bluetooth, and Nordics implementation is just following this spec. But this data format is also used for other things, like OOB data, where this field could be necessary.

For more info see GAP Assigned numbers @ bluetooth.org