S130 max concurrent central connections

RE: S130 max concurrent central connections

Cetin Mericli — Mon, 20 Apr 2015 07:28:44 GMT

I see, thanks a lot Hung.

RE: S130 max concurrent central connections

Hung Bui — Mon, 20 Apr 2015 07:20:12 GMT

@Cetin: I don't think there is any way to do that, strict timing needed to keep a connection. It's not possible to keep that when we disable and re-enable the softdevice.

RE: S130 max concurrent central connections

Cetin Mericli — Thu, 09 Apr 2015 14:46:45 GMT

Hi Ulrich,

Thanks for the reponse. I thought of that alternative. In the worst case it could be a fallback but the fact that you should be able to orchestrate 8 peripheral connections, disconnect, connect as a peripheral, and repeat the prcess is probably not very power friendly (I forgot to write but the system has to operate for a prolonged period when installed).

If there were a way of saving and resuming the soft device state (similar to the activation record concept in programming languages), things could have been slightly easier.

RE: S130 max concurrent central connections

Ulrich Myhre — Thu, 09 Apr 2015 10:11:08 GMT

The S120 2.0.0 has both a central and a peripheral included, but you cannot run both concurrently like with S130.

With the S120, you should be able to enable the SoftDevice as a (8-link) central, aggregate data, then disable the SoftDevice and enable it as a peripheral (S110-like). You are then able to broadcast any data you have saved, although all states and data related to the SoftDevice will be reset when disabling/enabling the SoftDevice.

Could this potentially solve your problem?

RE: S130 max concurrent central connections

Hung Bui — Tue, 07 Apr 2015 11:06:31 GMT

@Cetin:

I am not sure which could be easier, both approaches will have to deal with scheduling the manual connection event, 8 centrals links with 20ms interval will occupies the whole timeslot for radio. So the connection interval should be >20ms if you want to add a peripheral link in. Also, I don't think you would be able to support 6 packets per connection interval on the peripheral link.

There is no official information on the limiting factor on S130 that limit it to 3 central links. So I can't expose anything about that here.

RE: S130 max concurrent central connections

Cetin Mericli — Tue, 07 Apr 2015 06:03:40 GMT

Thanks a lot, Hung!

Should I implement my own central role or should I use S120 and try to implement a peripheral role on the side (I'm not sure if that would be possible or not).

Also, what exactly is the limiting factor in S130 that makes it difficult to support more than 3 concurrent connections?

RE: S130 max concurrent central connections

Hung Bui — Tue, 07 Apr 2015 03:30:49 GMT

@Cetin: i) Yes, it's true. S120 supports up to 8 central connections because it doesn't have peripheral role as with S130.

ii) Not much can be done to change that, at least for now. Future version of S130 may support more than 3 but that not what I can confirm. What you can do now if you want is to implement your own central role using timeslot API, but I don't think it's would be very straight forward and simple task.