Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Wed, 10 Mar 2021 12:01:15 GMT

Hi Jean,

I have updated to the internal. Thanks.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Thu, 04 Mar 2021 15:00:14 GMT

Hello,

Another information that could help. After upgrading nRF Connect (I was using 3.3.1), the behaviour changed. Having "nRF Connect/Bluetooth Low Energy" app will not make connection faster anymore, whereas opening JLink.exe still does the job.

So I tested all intermediate releases:

- Fo all releases from 3.3.1 to 3.6.0, I observe the same behaviour: Running JLink.exe OR opening "nRF Connect/Bluetooth Low Energy" makes device connection faster.

- With 3.6.1 only, Running JLink.exe makes device connection faster, but opening "nRF Connect/Bluetooth Low Energy" does not have any effect, the connection remains slow.

Looks like something related to this issue was changed in this last release.

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Thu, 04 Mar 2021 09:23:28 GMT

Hi Jean,

Thanks for the tests. I have reported to the internal for investigation.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Mon, 01 Mar 2021 14:31:30 GMT

Hello,

I could do some more testing, here is what we observe here:

- When nor JLink, nor nRF Connect are opened, service discovery and data transmission is slow

- When JLink.exe is opened, service discovery and data transmission is faster

- When "nRF Connect - Bleototh Low Energy" is opened, service discovery and data transmission is faster

So we could conclude that "nRF Connect - Bleototh Low Energy" may start JLink in the background making everything work fine. But:

- If I rename "C:\Program Files (x86)\SEGGER", and open "nRF Connect - Bleototh Low Energy", I get an error and, surprisingly, service discovery and data transmission remain faster....while I would expect it to be slow again as "nRF Connect - Bleototh Low Energy" could not run JLink....

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Mon, 08 Feb 2021 10:24:25 GMT

Hi Jean,

If you rename the path of the Jlink driver, the error might be expected because of the setting. Do you mean that the service discovery will not run faster in that case?

Could you also help to test if you open J-Link Commander? Does it also affect the time?

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Fri, 05 Feb 2021 15:43:01 GMT

Did some more investigations.

If I rename "C:\Program Files (x86)\SEGGER\JLink" (as "Jlink_").

When I run "heart_rate_collector" sample program or my programs using pc-ble-driver 4.1.2, they still work the same.

But when I run "nRF Connect"/"Bluetooth Low Energy" app, it reports:

2021-02-05T15:37:00.123Z ERROR Error while probing devices: Error occured when get serial numbers. Errorcode: CouldNotCallFunction (0x9)
Lowlevel error: INVALID_OPERATION (fffffffe)

So there is dfinitely something done in the background by "nRF Connect"/"Bluetooth Low Energy" through JLink. And I bet that's what makes the dongle behave right (high speed) when "nRF Connect"/"Bluetooth Low Energy" is opened on the machine.

Any idea what this could be?

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Thu, 04 Feb 2021 09:32:06 GMT

If that could help, it looks like having JLInk.exe running also makes softdevice run in a faster way. Could there by any link between JLink and "USB CDC ACM" that could explain that?

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Fri, 29 Jan 2021 11:49:53 GMT

If needed, I believe we could even consider hosting a Nordic engineer at our place (Grenoble/France) for some days to work together on the problem.

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Fri, 29 Jan 2021 11:39:59 GMT

Hi Jean,

I think we should look into this, but can't promise how soon. have a bit resourcing issue at the moment which we need to resolve.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Fri, 29 Jan 2021 09:48:06 GMT

Yes, this is definitely critical for us, as we are using BLE5 to transmit lots of data (notifications of 200 bytes data frames at 1kHz). This works fine when "nRF Connect" is opened on the machine, but has tones of data being lost when it's closed. So it makes it impossible for us to deploy the application to final users.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Fri, 29 Jan 2021 09:45:35 GMT

Hi Jean,

Unfortunately, the problem has not been uncovered due to the limited resource of the team. Is it a pressing matter would you say? May I know more about your concern? Please be free to let me know any thoughts.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Fri, 29 Jan 2021 08:22:49 GMT

Hello Amanda,

Did the team get a chance to look at this problem?

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Thu, 17 Dec 2020 14:02:26 GMT

OK. Enjoy the holidays and we'll see this in January!

Merry XMas and Happy New Year to you too.

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Thu, 17 Dec 2020 14:00:04 GMT

Hi Jean,

The nRF Connect BLE engineer said that it not easy to identify what nRF Connect for Desktop does that would affect this. Especially if the scenario also happens when using a third-party library like Termite. As the Christmas and New Year vacation coming, more and more engineers will start the holiday next week. The resource is limited and they need more time to figure it out. I am afraid the next update will be after the new year. Sorry for the inconvenience.

Merry Christmas and Happy new year.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Mon, 14 Dec 2020 12:47:09 GMT

Hi,

I observe the same thing with other applications that do not even use cout, so fflush can't be the cause of this problem.

Did the team working on "nRF Connect - Bluetooth Low Energy" app had a look at this? As launching their program makes service discovery faster, checking what their app does at startup is likely to help identifying what's going on. Is there any way to contact them and see if they could help? I could for instance test their program with different startup options to see if one impacts the behaviour or not.

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Mon, 14 Dec 2020 12:23:47 GMT

Hi Jean,

The engineer has no idea. Perhaps you could uncomment the fflush statements in the code, it could in theory affect performance, but not to such degree that it adds more than 100ms.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Thu, 10 Dec 2020 10:24:22 GMT

Hello Amanda,

Have you made any progress on that? This issue is really a problem here. I'm afraid that with no solution proposed we will have to switch to other BLE dongles (like Cypress) that do not have the problem.

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Fri, 09 Oct 2020 06:23:05 GMT

Hi Jean,

[quote user="Jean"]Do you mean that the fact that Termite is open makes service dscivery faster as we noticed here when "nRF Connect - Bluetooth Low Energy" is opened?[/quote]

Yes, so this is most likely something windows does when opening some software with serial support. I have reported to the internal for this behavior.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Thu, 08 Oct 2020 13:04:38 GMT

Hello Amanda,

Do you mean that the fact that Termite is open makes service dscivery faster as we noticed here when "nRF Connect - Bluetooth Low Energy" is opened?

Having you being able to reproduce the issue at some point is a good start. Please let me know what you can find out as being the root cause of the problem.

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Thu, 08 Oct 2020 12:31:41 GMT

Hi Jean,

I think the sniffer-logs doesn't help. Seems to only contain advertising packets up until connection. We can reproduce the same behavior by opening Termite, and I will report it to the internal to see this is a Windows "issue" or not.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Mon, 28 Sep 2020 13:55:28 GMT

Have you tried to reboot your machine? I noticed the impact of opening/closing "nRF Connect - Bluetooth Low Energy" may disappear at some point.

We can reproduce this issue on many different computers here, so there must be something wrong.

Could you analyse the sniffer logs? Are those different timings results visible in there?

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Mon, 28 Sep 2020 13:51:58 GMT

Hi Jean,

Unfortunately, I followed your instructions but the service discovery is still about 200ms while the nRF Connect - Bluetooth Low Energy was opened. I could not reproduce on my side.

-Amanda H.

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Mon, 21 Sep 2020 13:05:44 GMT

Hi again,

I must admit the documentation is now better than it used to be for the sniffer. I could install it and make it work easilly. Here are the logs, one with a slow service discovery (~200ms) (when "nRF Connect - Bluetooth Low Energy" was closed), one with a fast service discovery (~50ms) (when "nRF Connect - Bluetooth Low Energy" was opened).

Hope this can help,

kind regards,

Jean

devzone.nordicsemi.com/.../sniffer_5F00_discovery_5F00_with_5F00_without_5F00_nrf_5F00_connect.zip

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

jpo38 — Mon, 21 Sep 2020 12:25:29 GMT

Hi Amanda,

Have you tried to reproduce the issue first? I doubt sniffer logs will help if you cannot reproduce the issue.

I've already been asked for sniffer log in the past (https://devzone.nordicsemi.com/f/nordic-q-a/44922/s140-pc-ble-driver-4-0-0-freezes-when-receiving-too-many-data). I'll try to produce them, but it's always hard to do (lots of stuff to install and setup) and I never saw them leading to any problem solving.

Kind regards,

Jean

RE: Why having "nRF Connect - Bluetooth Low Energy" open makes my connection faster

Amanda Hsieh — Mon, 21 Sep 2020 11:21:40 GMT

Hi Jean,

Could you kindly provide the sniffer log to help check the issue? Thanks.

-Amanda H.