BLE Streaming Question

RE: BLE Streaming Question

run_ar — Thu, 24 Aug 2017 09:08:27 GMT

I see you already created a question for this. So let's try to follow up there instead.

RE: BLE Streaming Question

Colt — Wed, 23 Aug 2017 23:05:46 GMT

I am having the same issue with the s332 and communicating between 2 nRF52's. One is the central and one is the peripheral. I need to TX only 9 bytes from the peripheral to the central as often as possible and as constant as possible.

What is the best setup for this? How fast of a rate can be achieved?

RE: BLE Streaming Question

run_ar — Mon, 24 Oct 2016 09:26:25 GMT

Looks like the next connection event is scheduled during housekeeping at the end of an ongoing event. This means that it's not possible to send a packet in the first event after it's added to the buffers (the LL doesn't know there is a packet). So if you use the active signal and call sd_ble_gatts_hvx before an event, the delay will be less than Connection interval + NRF_RADIO_NOTIFICATION_DISTANCE. Do you have a particular use case for this?

RE: BLE Streaming Question

dgutierrez — Fri, 21 Oct 2016 14:59:46 GMT

Tried enqueueing on the inactive event (NRF_RADIO_NOTIFICATION_TYPE_INT_ON_INACTIVE), and still the same results.

RE: BLE Streaming Question

dgutierrez — Thu, 20 Oct 2016 15:29:21 GMT

Is there a way to modify the soft device's transmit queue contents? If I could keep two in the queue but overwrite the first element each time, that removes one connection interval of latency.

RE: BLE Streaming Question

dgutierrez — Thu, 20 Oct 2016 15:01:13 GMT

s132 v3.0.0

RE: BLE Streaming Question

run_ar — Thu, 20 Oct 2016 14:58:37 GMT

Which version of S132 is this?

RE: BLE Streaming Question

dgutierrez — Thu, 20 Oct 2016 14:21:37 GMT

Hi,

I did try enqueuing with the on_active event, but didn't try the on_inactive event. Will try that and report, thanks.

As to a longer interval, that was interesting. Fastest the Android phone could go was an interval of 11.25 ms. By not keeping the queue always full with two packets, a notification happens every other interval (effectively a 22.5 ms interval) and there are no multiple packets. In between notifications an empty PDU is exchanged. However when I change the connection params to have a 22.5 ms connection interval and notify every interval the same problems occur which makes it seem like it has to do with the way the queue is being used...

RE: BLE Streaming Question

run_ar — Thu, 20 Oct 2016 12:46:40 GMT

Have you also tried placing the packet in the buffers on the NRF_RADIO_NOTIFICATION_TYPE_INT_ON_INACTIVE event or only in case of the on_active event? Could you also try to use a slightly longer interval to see what happens?