keeping connection alive for long times

RE: keeping connection alive for long times

Norandy — Wed, 14 Sep 2022 06:36:07 GMT

Hi guys, I know this is a old topic :) but I would like to know if it is possible to share your configuration regarding the way to keep a connection alive a long times. Let me know if I could do anything in that way. Thanks

RE: keeping connection alive for long times

Hung Bui — Fri, 13 Feb 2015 14:52:12 GMT

@Jaciroscar : it's pretty normal to have RSSI at -45 dbm. You will see that with our development board as well.

Yes, you can send the board to us and we will do the antenna tuning and optimize the board for you. It's free and take about 3-4 weeks.

I would suggest you to create a support case on MyPage (on Nordic website ) for the request. Our hardware experts will take it from there.

RE: keeping connection alive for long times

spmbx — Fri, 13 Feb 2015 06:27:04 GMT

Thanks for the explanation, things are clearer to me now. I tweaked with these settings and were able to improve the connection time to a few hours. But I am suspecting there is something wrong with the board layout that is causing the packet loss. For instance, the maximum RSSI level I´m getting is -45 dbm, when it is supposed to be 0 dbm. Can I send the PCB layout to Nordic analyse if there is any error?

RE: keeping connection alive for long times

Hung Bui — Thu, 12 Feb 2015 15:00:00 GMT

Yes, by theory even without any activity the connection should be kept. (Empty payload packets are automatically sent on every connection event to keep the connection) Your supervision timeout is pretty short if there are only several packet drop it would cause connection timeout.

And please noted that the maximum and minimum connection interval is only used as the preferred request from peripheral, it depend on the central to decide which connection interval will be used. So there is a chance the actual connection interval is not between 12.5ms and 22.5ms (with most Android phone it won't be in that range). I would suggest you to change supervision timeout to 1 to 4 seconds for example.

RE: keeping connection alive for long times

spmbx — Tue, 10 Feb 2015 17:24:53 GMT

Hi Hung Bui, Unfortunatelly I don´t have a packet snnifer. Just to confirm, even without data transfer, the connection should be kept alive for hours/days ideally? My current parameters are Maximum connection interval=22.5ms; Minimum connection interval=12.5ms; Slave latency=0; Connection Supervision timeout=100ms.

RE: keeping connection alive for long times

Hung Bui — Tue, 10 Feb 2015 11:28:55 GMT

Hi Jaciroscar,

Could you give me more information on the connection parameters (connection interval, slave latency, connection timeout) that you used for your device ?

If you have connection timeout = 100ms and if you have connection interval = 35ms for example, the connection may be timed out if there are 3 packets drop. This could very easily happens if there is some interference. If you can provide a sniffer trace, it would be useful.

I do agree that it's not very stable on some Android phones to keep the connection for a long time, but I'm talking about several hours or days not just few minutes as in your case.

RE: keeping connection alive for long times

spmbx — Mon, 09 Feb 2015 04:15:34 GMT

Hi Locky, Do you think the correct behavior would be to the connection be maintained even without data transfer? I've tried it with Sony Z2 and M2 Aqua, both running Android 4.4.4 and a Galaxy S"x" with Kitkat (I dont remember the exact model and Android version, and I'm not with the phone here right now). Regards

RE: keeping connection alive for long times

Locky — Mon, 09 Feb 2015 04:00:17 GMT

Which Android device are you connecting to? Do not rule out the phone itself as there are several Android phones (even high end ones; Nexus 4, HTC One M8) which have trouble keeping a BLE connection for long. Also which version of Android does this phone have?