Disconnection procedure after LL conn. parameter update leads to supervision timeout

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Hung Bui — Fri, 24 Jun 2016 07:00:11 GMT

@Thangaraj: The issue disappeared when moving to S130 v2.0. Could you please check ?

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Thangaraj — Thu, 23 Jun 2016 12:08:45 GMT

Am facing the same issue, Was this fixed ??

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Tue, 23 Feb 2016 10:05:17 GMT

Hi Hung. Sorry for the late response! I've now created a case via MyPage and uploaded the demo application there. Kind regards

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Wed, 27 Jan 2016 13:04:50 GMT

Hi Hung. Ok, I will create a stripped-down demo application and open a case via MyPage due to confidentiality. Unfortunately, I will not have time to do this until next week. Kind regards

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Hung Bui — Thu, 21 Jan 2016 08:51:00 GMT

Hi Remo,

The trace I attached on Dec 17 in the answer already has the LL_TERMINATE_IND right 1 connection event before the disconnection.

Please send me the full project, that I can compile and test here. If there is confidential information concern, please create a case on Mypage on our website, attach the project there and add link to this case on devzone.

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Thu, 21 Jan 2016 07:44:23 GMT

My mistake, 16 is of course one connection interval before the instant, and not two. Can you send me a sniffer trace where you terminate the link in the connection interval before the instant? Maybe I see some differences between our procedures... I've sent you some code snippets via PM. Do you need more?

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Hung Bui — Mon, 18 Jan 2016 13:48:55 GMT

@Remo: 0x0011 = 17. I am not sure 16 is one instance before or two ? I tried both 1, 2 3 instance before, all worked. If you can provide me a simple example (modified code from SDK for example) that I can reproduce here then it's easier.

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Mon, 04 Jan 2016 15:12:26 GMT

Hi Hung.

I think it depends on when the LL_TERMINATE_IND is sent and when the new connection parameters would by applied. I added a new sniffer trace in which the nRF sends the LL_TERMINATE_IND packet two connection intervals before the Instant. In this case the BLE_GAP_EVT_DISCONNECTED event occurs right afterwards.

So far, I tested following cases (the Instant was always 0x0011):

nRF sends LL_TERMINATE_IND in connection event 15 -> Good
nRF sends LL_TERMINATE_IND in connection event 16 -> Fail
nRF sends LL_TERMINATE_IND in connection event 17 -> Good

Can you please try to terminate the connection two intervals before the instant and check if you can reproduce it?

Kind regards

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Hung Bui — Fri, 18 Dec 2015 16:30:17 GMT

Hi Remo,

I tried with different setup (including 48.75 ms interval) and still couldn't reproduce it here. You can try to change the connection parameter on your side to check if it helps. You can use the Master Control Panel application on PC, you have full control over the central device with this application.

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Thu, 17 Dec 2015 16:57:36 GMT

Hi Hung. Thank you for your sniffer trace. I saw that the connection interval in "your" connection is 200ms while the interval in "my" connection is 48.75ms. Maybe that has an influence... Is it possible that you can send me your code so can I can look for differences?

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Hung Bui — Thu, 17 Dec 2015 12:48:05 GMT

Hi Remo,

I tried many different scenarios here but non of them showed the issue you were having. You can have a look at the trace attached here (using Nordic sniffer ), you can use Wireshark to open (you need to run Nordic sniffer to install the plugin)

You can find that the advertising started right after the LL_TERMINATE_IND packet, suggesting that the Disconnected event was received right after packet.

trace_PUpdate_Disconnect.pcapng

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Thu, 17 Dec 2015 08:36:54 GMT

The problem with providing a simple code is, that our nRF application is controlled by another controller via commands on the UART interface. E.g. one command starts the advertising and another command terminates the connection. Therefore, would just some particular code snippets be enough?

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Thu, 17 Dec 2015 08:33:14 GMT

Hi. I have uploaded another sniffer trace in which the last connection was terminated successfully (the disconnected event was received immediately). All previous connections were terminated and the disconnected event occurred first after the supervision timeout. The phrase "Now it happens sometimes" means that the supervision timeout occurs in most cases. That is, when the 'instant' of the connection parameter update applies after the connection should be terminated, as you can see in the second sniffer trace file.

The occurrence of the problem depends on the timing when the connection update request is sent (and the instant signaled by the central) and when the terminate request is sent. When you tried to reproduce it, could you verify with the sniffer that the terminate request was sent before the 'instant'?

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Hung Bui — Wed, 16 Dec 2015 13:33:43 GMT

Hi Remo, The sniffer wouldn't tell much. I'm seeing the peripheral didn't start to advertise after disconnection. I assume you added a breakpoint or didn't start advertising when disconnected in your application. When you mentioned "Now it happens sometimes", how often it was ? Have you found a way to reproduce the issue all the time ? I tried several times here but couldn't reproduce. A simple code that can show the issue would be great.

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Remo — Wed, 16 Dec 2015 07:11:07 GMT

I've uploaded the sniffer trace. Can you work with this format? I have to recheck if I can provide you the code. Kind regards

RE: Disconnection procedure after LL conn. parameter update leads to supervision timeout

Hung Bui — Tue, 15 Dec 2015 11:54:48 GMT

Hi Remo,

Could you provide the sniffer trace and maybe the example code that can generate the issue. I tried here but couldn't reproduce that. The BLE_GAP_EVT_DISCONNECTED event came right after the nRF51 sent the LL_TERMINATE_IND.