iPhone7 + nrf52 + SDK12/s132 doesn't connect

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

OldisGold — Tue, 29 Nov 2016 21:02:31 GMT

Thanks Ray your solution fixed the problem

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Tue, 29 Nov 2016 18:58:22 GMT

This forum software made hash of my comment. I stuck it in a text file. Hope this helps. dl.dropboxusercontent.com/.../foo.txt

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

OldisGold — Tue, 29 Nov 2016 18:35:57 GMT

Hi Ray, Can you please share the workaround involving manually initiating MTU request. We are having connection problems with Softdevice 3 and ios 9.3.5. We can use a little help.

Thanks,

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

run_ar — Thu, 06 Oct 2016 06:55:01 GMT

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

RK — Wed, 05 Oct 2016 11:46:20 GMT

nice to have a resolution - I was pretty sure the whole way through it had to be an iOS bug, that was the only thing which made sense from the traces, but it's nice to have that confirmed, and even nicer for Apple to have already fixed it.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Wed, 05 Oct 2016 11:10:36 GMT

Just an update after working with Nordic support.

we did identify a workaround involving manually initiating an MTU request in the CONNECT event, however...
it is clearly an iPhone 7 iOS bug in 10.0.1 and 10.0.2, and is now fixed by Apple in the 10.1 beta

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

RK — Mon, 26 Sep 2016 14:07:59 GMT

6s isn't doing the data length extension query at all, so perhaps the 6s hardware doesn't support it. So in that way it looks just like the 5s on iOS 9.x

7 does the data length extension query, that's the major difference. In the case of the nrf51822, that replies with unknown because it's unknown (S130 doesn't support it), S132 replies to it with a fairly default response of 27 bytes Tx/Rx and the minimum timeout for each, a response which as far as I can see is perfectly correct, and I've looked at the bytes in it to check. The 7 then does a feature request, again the reply seems perfectly fine, and never says anything after that.

This is why I suggested actually setting a larger data packet extension, see if that makes a difference. The one it sends is fine, you can support the extension but still use 27 bytes, but somewhere around there is where the phone is getting upset.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Mon, 26 Sep 2016 13:59:29 GMT

Here are two captures from nrfconnect just trying to open the device to list services. Both are iOS 10.0.1.

From the 6s, that works perfectly:

dl.dropboxusercontent.com/.../nrfconnect-6s.pcapng

From the 7, which fails:

dl.dropboxusercontent.com/.../nrfconnect-7.pcapng

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Mostafa Berg — Mon, 26 Sep 2016 13:14:06 GMT

Perfect!, the final thing we can ask for now is to see the difference between the iPhone 6s and the iPhone7 to see if there's any differences, is it possible to ask for another log ? doing the exact same thing with both devices ? too much requests I'm sorry :)

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Mon, 26 Sep 2016 13:11:20 GMT

BTW I have tried it just now on an iOS 10.0.1 device, an iPhone 6s, and it works fine.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Mostafa Berg — Mon, 26 Sep 2016 12:35:14 GMT

I updated my comment after seeing that, I'm also interested in knowing if the iPhone 6 is also on iOS 10 or not, if not, it would be a great idea to try updating one of those phones to iOS 10 and see if they'll reproduce the issue. again, this doesn't mean that it's surely a softDevice issue as @RK says, it could still be an iOS10 bug, so verifying it with another phone will help us double check at least, thanks

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

RK — Mon, 26 Sep 2016 12:23:19 GMT

I still don't think that's the case based on your capture, the soft device has replied to all messages correctly, the phone has stopped sending.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Mon, 26 Sep 2016 12:18:49 GMT

Thanks. Please see remainder of answer in my other comments below.

The 5s is running 9.3.5, and the 7 is running 10.0.1.

The iPhone 7 works perfectly against my app when my app is running on nRF51822 hardware with the S130 softdevice.

The iPhone 7 also works perfectly against my app when my app is running on nRF52832 hardware with the S132 softdevice from SDK11 and compiled using SDK11.

The iPhone 7 fails only against my app (and nRF Connect, and nRF Toolbox) when my app is running on nRF52832 hardware with the S132 softdevice from SDK12 and compiled using SDK12.

I could be wrong of course, but even if it is a new behavior introduced by Apple, it looks like a bug that is correctable in the softdevice or SDK.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Mostafa Berg — Mon, 26 Sep 2016 12:08:12 GMT

That's interesting, Will try to get hold of an iPhone 7 to test this out, which version of iOS do you have on the iPhone 6 that worked by the way ?, if it's not 10 , can you try updating one of those iPhones to iOS 10 and see if the issue reproduces then ?, this will help a lot

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Mon, 26 Sep 2016 12:02:04 GMT

Yes, Mostafa. The entire reason I ended up using Ned connect, and using the sniffer, is that it fails in y own app.

My app, just like nrf connect and nrf toolbox, fails with an incomplete connect.

And yes I do the toggle to flush but cache as a matter of course during these tests.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Mostafa Berg — Mon, 26 Sep 2016 06:36:20 GMT

Hi @ray, to help find out where the issue stems from, can you try to connect to the peripheral with any other app than nRF Connect and see if it reproduces ? also it's always a good idea to unpair from that peripheral and toggle airplane mode to flush the BT cache. let me know and we can take it from there

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

RK — Sun, 25 Sep 2016 03:22:14 GMT

couple of things you could try - actually set a long data packet length, set it to 251 bytes, which is what the phone is claiming to support, see if that jerks it out of inactivity.

One thing to note - wireshark (still) decodes feature bits backwards, so the softdevice is actually reporting LE Security + LE Data Packet Extension, not what wireshark dissects, I've reported this, should have done it years ago, it's been like that since version 1.08 or something.

Also since the softdevice does support LE Ping I don't know why that flag isn't set - Nordic?

And finally it's rather odd that the phone starts the Data Length Extension procedure before it checks the features flag, but it doesn't really matter, odd though.

On the iOS side are you getting the bluetooth Connect callback and starting characteristic discovery, or is the phone not even reporting itself connected?

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

RK — Sun, 25 Sep 2016 02:07:41 GMT

No I still think it's iOS BLE4.2 support which is most-likely at fault here. The nRF52 has replied to every message sent by the phone, properly, fully and completely and continues to respond to empty PDUs which the phone continues to send. The connection isn't timing out, so the phone isn't expecting a reply from the nRF52 which it's not getting. iOS hasn't sent an MTU request, not that it really needs to, but it's unusual, however the next request, either MTU or feature or discovery needs to come from iOS, there's nothing the softdevice has to send at this point.

And in the previous iPhone7/SD130 capture you can see that the softdevice responds to the data length request with unknown, that's the point of difference. In the S132V3 version, nRF responds with 0x1b as the tx and rx lengths, correctly. It's after that that iOS stops doing anything.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Sun, 25 Sep 2016 01:50:13 GMT

Well indeed it works with the sdk11 soft device. And way above you will see a capture of the iPhone 7 talking to an nrf51.

Bottom line is that indeed it is likely softdevixe behavior that needs to be fixed to do whatever it was that it used to do in the sdkv11 softdevice.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

RK — Sun, 25 Sep 2016 00:00:13 GMT

Doubt it's an SDKV12 SDK issue, more likely an S132 V3 issue. The captures don't show anything particularly interesting, it does show the exchange of max TX/RX length information (LL data length) in the bad capture because the softdevice identifies as BTLE 4.2.

It would be interesting to see a dump of iPhone7 -> S132V2 (SDK11 if you like) or to nrf51822 running S130, that should show a similar start. The dump you have the phone is BTLE 4.1

I don't understand the random L2CAP message from the master in the middle of the whole thing, in either dump, it's marked as a continuation but doesn't continue anything.

I'd be inclined to say iOS bug at this point. I don't know if any phone previous to iPhone 7 identifies as BTLE 4.2, and there can't be many products out there running S132V3. The nRF52 has replied to everything, the phone isn't asking more questions, which it should be.

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Sat, 24 Sep 2016 16:24:01 GMT

I know that this hasn't gotten attention yet, but I really hope someone from Nordic would please comment because it's really a blocker.

I have now reduced this to being an SDK V12 issue. Meaning, the following all work perfectly with my app and Nordic's own: iPhone 5s + nRF51822 + SDKV11/S130 iPhone 7 + nRF51822 + SDKV11/S130 iPhone 5s + nRF52822 + SDKV12/S132

It fails, with my app and Nordic's own, on: iPhone 7 + nRF52822 + SDKV12/S132

FYI, because I know that this is likely to be the very first thing that a Nordic employee would reasonably ask, I've now eliminated my app from the equation.

These two captures are from the SDKV12 ble_peripheral hrs app, using the up-to-date nRF Toolbox app on the iPhone.

I'm running the hrs app on my nRF52832.

This capture is done using the iPhone 5s running iOS 9.3.5, and it works perfectly:

dl.dropboxusercontent.com/.../hrs-nrf52-iphone5s-good.pcapng

This capture is done using the iPhone 7 running iOS 10.0.1, and it fails the same way as my app failed above:

dl.dropboxusercontent.com/.../hrs-nrf52-iphone7-bad.pcapng

RE: iPhone7 + nrf52 + SDK12/s132 doesn't connect

Ray — Fri, 23 Sep 2016 16:49:11 GMT

Actually, here are some better captures. This shows the protocol differences much more clearly.

This is a capture of the iPhone 7 using nRFConnect (not my app).

This capture is the IPhone7/nRFConnect connecting to an nRF51: dl.dropboxusercontent.com/.../nrfconnect-nrf51.pcapng

This is capture is connecting into the nRF52: dl.dropboxusercontent.com/.../nrfconnect-nrf52.pcapng

What you'll see is that all that happens on the nRF52 is:

SLAVE LL_VERSION_IND
SLAVE LL_VERSION_IND
MASTER LL_VERSION_IND
SLAVE 35 Control Opcode: Unknown
MASTER 35 Control Opcode: Unknown
SLAVE LL_FEATURE_REQ
SLAVE L2CAP Sent
MASTER LL_FEATURE_RSP

...and that's all. There's no further dialog, and no services listed in NRF Connect.