RE: BLE Connection strategy

mcan — Tue, 13 Jun 2023 14:03:06 GMT

Ahh, (for reference), my mistake were that I hadn't configured the CONFIG_BT_PRIVACY flag.

RE: BLE Connection strategy

mcan — Fri, 02 Jun 2023 16:14:08 GMT

Thanks! This seems to work quite nice!

One thing that doesn't seem to work though, the iOS device has privacy, and after address change the peripheral doesn't seem to recognize the device.

RE: BLE Connection strategy

SwRa — Fri, 02 Jun 2023 11:35:37 GMT

Hi Markus,

I think this would be something that you could consider: https://github.com/nrfconnect/sdk-zephyr/tree/main/samples/bluetooth/peripheral_accept_list

Regards,

Swathy

RE: BLE Connection strategy

mcan — Thu, 01 Jun 2023 16:22:31 GMT

So my first attempt was to just turn on and off the advertisement, but as I said I need to be able to reconnect without any user input.
Button press + 2 min: advertising.
Other: advertising off.

Next attempt was to try make the peripheral "invisible" by using non-discoverable, limited-discoverable etc. That didn't work because iOS didn't care about that and showed the peripheral whatever discoverable mode it had.
Button press + 2 min: advertising limited- (or general-) discoverable
Other: advertising non-discoverable

Now I'm trying directed connectable instead.
Button press + 2 min: advertising general discoverable, connectable. (on connection save currently connected device)
Other: advertising, directed connectable (last saved current device)
Result: I'm not sure if this works because I get a -5 (I/O error) when trying to start the advertising (something like this):

err = bt_le_ext_adv_create(BT_LE_ADV_CONN_DIR_LOW_DUTY(bt_conn_get_dst(current_conn)), NULL, &adv_set);
if (err) {
    LOG_ERR("Create extended advertising set_id failed (err %d).", err);
    return err;
}
err = bt_le_ext_adv_set_data(adv_set, ad_non_discoverable, ARRAY_SIZE(ad_non_discoverable), sd, ARRAY_SIZE(sd));
if (err) { // <<<--- This is where it fails
    LOG_ERR("Failed to set advertising data (%d).", err);
    return err;
}
err = bt_le_ext_adv_start(adv_set, NULL);
if (err) {
    LOG_ERR("Extended advertising failed to start (err %d).", err);
    return err;
}
LOG_INF("Directed advertising successfully started");

Took inspiration from these two threads (that pointed out that I need to use the extended API):
How to use Directed advertising (high duty cycle) in Zephyr development?
Directed Advertising not seen by the addressed device

Worst part is that I'm not even sure that if I get the working, I'm not sure this is a viable solution for my problem.