multiple writes and notifications per connection interval

[Jim Dattolo]

I know that it can be done and I have read the other posts. I'm still running on SDK8.0.0 with both a S110 and a S130. Using wireshark and the nordic sniffer firmware on a dongle I can see only one 20 byte attribute write command (not the req with response type) going out per connection interval. I also see the same thing on all notify type HVX messsages. I often see an empty PDU coming back interleaved in the writes and HVXs.

When I do my writes I call the stack send until I get back the no buffers return and then start queueing up and then every time I receive a TX Complete event I send the next one in my buffer. I always seem to get a TX Complete with only 1 in the count. I would have expected to pipeline my 4 writes into a single connection interval but that is not the case.

Any ideas? I have it on my plate to update to the latest stack, however I do want to put this issue to bed before stirring things up with new stack and SD. Is there an issue with 8.0.0 that updating will fix?

[Petter Myhre]

Since you are using SDK 8.0.0, I'm guessing you are using S130 1.0.0. It can only receive 1 notification per connection interval, and can only send 1 write command per connection interval. Please see Chapter 16 in S130 SoftDevice Specification v1.0 for more information.

The S130 2.0.0 can recieve 6-7 notifications (20B) per connection interval, and send 6-7 write commands (20B) per connection interval. If this is something you want I recommend you to upgrade to this version, and use it together with SDK 11.0.0.

[Jim Dattolo]

That would be the info I need! I didn't want to upgrade unless there was a reason to and the release notes for SDK11 didn't mention anything about the number of packets per connection interval. I'll start working on upgrading to 11 right away.