HCI Connection Timeout too often.

RE: HCI Connection Timeout too often.

David Edwin — Tue, 02 Feb 2016 15:53:49 GMT

There should not be a difference for CPU activity. CPU activity is proportional to the number of links. If a link is at 20ms or 21.25 ms, there is no difference.

RE: HCI Connection Timeout too often.

Marius Heil — Tue, 02 Feb 2016 15:51:25 GMT

OK, that explains quite a bit if the Link Layer Connection update is not used. Using different intervals seems to e counter-intuitive at first, but I guess that should work. Thanks for the tip, will try that. But I think this is going to cost more energy, right? Because now the CPU needs to be woken up multiple times and before it would have had the possibility to sleep for a long time and then activate for all connection events.

RE: HCI Connection Timeout too often.

David Edwin — Tue, 02 Feb 2016 15:35:37 GMT

CONN_PARAMS_UPDATE is not used now, but will eventually get added. I would suggest closely spaced intervals for the links (master and slave) but none of them should be identical. For example, 18.75ms, 21.25ms, 22.50 etc. Let me know how it works for you.

RE: HCI Connection Timeout too often.

Marius Heil — Tue, 02 Feb 2016 12:49:59 GMT

Thanks, I use the same connection intervals for all nodes. When using different values, I use perfect multiples. One more question here: Does the Softdevice use LL_CONNECTION_UPDATE_REQ with WinOffset to coordinate its connections or does it simply disconnect a connection if it interferes with another scheduled connection?

RE: HCI Connection Timeout too often.

David Edwin — Tue, 02 Feb 2016 12:29:16 GMT

I think this issue is happening as the connections get synchronized at some point and start trashing each other's packets, resulting in a link loss. You should be able to re-connect and proceed.

You can also check if this happens with connection intervals that are not perfect multiples of each other for the neighbor nodes, so they do not trash each other so often.