Directed Advertising Peripheral

[Luke Richards]

Hi

I have a Nordic nRF51 as a Peripheral. I have it open advertising until it connects for the first time to an Android handset.

When a connection is made it stays in directed mode advertising so that no other devices can connect in the future (for security purposes)

On a power cycle of the Android handset, it changes its address so I can never connect to the peripheral again, since its directing at the old handset address.

Any help would be much appreciated

Regards Luke

[Hung Bui]

Hi Luke,

Sorry that I didn't check you are using S130. Advertising with privacy is not support on S130.

In your case, I would suggest doing whitelisting. Whitelisting meaning you advertise in open, discoverable mode but only the central device that has been bonded with your can connect. The peripheral will discard the connect request from other central.

Usually, what we do in our mouse and keyboard reference design is to advertise in directed advertising for a short period of time (few hundred milliseconds) before switching to normal advertising with whitelist. This is to take advantage of the high duty cycle adv interval directed advertising can have (3.5ms) to connect quickly. But this mode consume high power consumption so it should only be used short period of time.

You can refer to our ble_app_mouse and keyboard example in the SDK to see how we do whitelisting.

[Loai]

Hello Hung Bui,

I hope you are still part of the network. I noticed that you were discussing this topic couple of years ago which is somehow related to my issue.

I am using nrf5340 Audio DK, and I would like to implement this Whitelist on the peripheral (headset) device to only connect to a specific central (gateway). I actually have 2 centrals so using the whitelisting, I would like to shift the connection between them when the user presses a button for example, so I thought that whitelisting can help the headset to connect with the device specified. Would you mind to guide mw on how I can do that or maybe show me an example I can refer to?

Thanks!

[Hung Bui]

Hi Loal, 
I'm not an expert with the Audio SDK so I can't really give you the exact answer. I would suggest to create a new case. 
If the Audio stack use the same mechanism as normal BLE then it shouldn't be a problem change the whitelist or change the directed advertising to point to a single central and switch between when them.