direct advertising while having established connection

[Matej]

Hi,

I'm wondering if I'am able to direct advertise when I have established connection (edit: according to this established connection nrf5x is master (central role))?

Of course with usage of S130 or S132.

Thank you for info.

BR, Matej

[RK]

I wouldn't think so - directed advertising is connectable and if you are in a connection already, the current softdevice only supports one peripheral connection, so any advertising would have to be non-connectable and hence not directed.

I guess that will change when the softdevice supports multiple peripheral connections.

[Matej]

I edit my question -> nr5x is master so it's in central role... Regarding that S130 and S132 support 1 peripheral and 3 central connections this should work...

I'm a bit worried about timeslot scheduling -I'm a bit worried about timeslot scheduling – connectable undirected advertising has possibility to set advertising interval… Directed advertising has two duty cycle advertising (Refer to BLE Core Specs, Vol6, Link Layer Specifications, 4.4.2.4.1 and 4.4.2.4.2. -At high duty cycle directed advertising, time between two ADV_DIRECT_IND PDUs is less then 3.75ms and after 1.28s is advertising finished

• At low duty cycle directed advertising time between two ADV_DIRECT_IND PDUs is less then 10ms. The advertising event shall be closed after advertising interval…

[Matej]

• So is this advertising interval settable?
• Is resolution of setting this advertising interval “big enough” that I can have established all three connections as central (there is still free one peripheral) and I can still direct advertise?

Thank you for clarifying – this feature is important to us that we can satisfy project requirements.

[Matej]

If i refer to BLE Relay example... Are we able to direct advertise to Collector if we already have established connection to Heart Rate Sensor or Running speed sensor?

Thank you

[RK]

There's a whole chapter on this in the softdevice spec, which goes into detail about which events get priority in different situations. It's chapter 14 and has a paragraph dealing with directed advertising when the device is also doing other things. It seems to me that you can do what you want, you may not send out all the advertising packets you would if there was nothing else running, but the device will still advertise as much as it can.

If you've not read that chapter - you should. This was the S132 V2 0.5 spec I was just looking at.