Receiving data and advertisement in the same time slot

[T IJ]

Hello,

As I am new to the world of bluetooth and its stack I have a question which I cannot find the answer for on the internet.

I've read a ton of posts on the devzone as well but I haven't gotten my answer.

Is it possible to receive a data package and a advertisement package in the same time slot or do they need a separate slot?

Another question I have is, about using the DLE (data length extension) and sending multiple data packages in a single time slot.

Can the master tell the slave to send one or two data packages in a single time slot, and if it is possible, how do I implement it.

Kind regards to anyone reading,

T. IJsselmuiden

[Dmitry]

Hello,

T IJ said:

Is it possible to receive a data package and a advertisement package in the same time slot or do they need a separate slot?

Do you mean softdevice timeslot API? You're on your own inside a timeslot. Maybe I didn't understand your question clearly, but advertisings and data packets are not synchronized in any way and transmitted at different channels, how do you expect to receive them in one timeslot?

T IJ said:

Can the master tell the slave to send one or two data packages in a single time slot, and if it is possible, how do I implement it.

Yes, the master sets MD (more data) flag to indicate that it will transfer more than one packet. It does that even without DLE - you can send 3-4 packets in a single connection event with default settings.

[T IJ]

I mean in a single bluetooth time slot of approx. 7.5 ms.

For instance, I am communicating with 4 devices, each one is getting 7.5 ms of time to transmit data to the master, this is repeated every 30 ms.

The master sends out a advertisement package during this 30 ms time period. 

Is this possible or do I need a separate time slot for this

[Dmitry]

In softdevice, advertiser and peripheral connection are scheduled independently, so you will have collisions between them: sometimes a connection will win (advertisement is skipped), sometimes an advertisement (lost connection event). You can try to schedule "earliest possible" timeslot for advertisement with timeslot API, and send an advertisement directly by radio hardware.

See https://infocenter.nordicsemi.com/pdf/S132_SDS_v7.1.pdf, chapter 15, about timeslot scheduling.