IOS Disconnects after exactly 33 seconds with NRF Connect not other app, Android no issue

RE: IOS Disconnects after exactly 33 seconds with NRF Connect not other app, Android no issue

Einar Thorsrud — Thu, 07 Jun 2018 07:14:58 GMT

Unfortunately, I expect that there will always be some bugs with some of the examples. However, we try to fix the issues (big or small) when they are found, and include the fixes in future SDK releases.

Which example in which SDK version have you based your code on?

RE: IOS Disconnects after exactly 33 seconds with NRF Connect not other app, Android no issue

SRA — Wed, 06 Jun 2018 17:57:49 GMT

Ok, that explains nrfConnect. But not why I'm missing an attribute on my handle 15 but not it's identical copy.

It also doesn't explain or excuse that Nordic plays really fast and loose with event handling. SOMETIMES an event is handled in the examples, SOMETIMES it's not. This is pretty unacceptible to me. The firmware should always be ready to handle anything the softdevice comes up with. You just have to hope you based your code on "the right" example.

RE: IOS Disconnects after exactly 33 seconds with NRF Connect not other app, Android no issue

Einar Thorsrud — Wed, 06 Jun 2018 11:59:50 GMT

I just discussed with one of the developers of nRF Connect for iOS. nRF Connect will do a service discovery after connection, and try to read all characteristics. This is a choice they made for nRF Connect which you can always discuss (and Apparently LightBlue does it differently), but there is nothing illegal about it with regard to the BLE specification as far as I can see. The reason it caused problems in the first case in this thread was the incorrect implementation on the nRF side (not handling the BLE_GATTS_EVT_SYS_ATTR_MISSING event).

RE: IOS Disconnects after exactly 33 seconds with NRF Connect not other app, Android no issue

SRA — Tue, 05 Jun 2018 16:24:40 GMT

Why would phone try and do that though?

I have three errors like this in my log, at least one is associated to a real handle with a CCCD that is defined exactly like another one next to it, that one has no errors during this service discovery. So it sure seems like maybe I'm missing a descriptor or something.

RE: IOS Disconnects after exactly 33 seconds with NRF Connect not other app, Android no issue

Einar Thorsrud — Tue, 05 Jun 2018 09:26:10 GMT

Hi,

The Attribute Not Found is because the iPhone (nRF Connect app) attempts to read a handle (in a range) which does not exist. This is not illegal.

RE: IOS Disconnects after exactly 33 seconds with NRF Connect not other app, Android no issue

SRA — Mon, 04 Jun 2018 23:32:59 GMT

While I'd still like to see what someone from Nordic has to say about Attribute Not Found... I fixed the 33 second issue and NRF Connect and LightBlue not working - the events BLE_GAP_EVT_CONN_PARAM_UPDATE and BLE_GATTS_EVT_SYS_ATTR_MISSING in the on_ble_event handler weren't being handled.

Most of the fix in my case seems to have been BLE_GATTS_EVT_SYS_ATTR_MISSING to which all I do now is sd_ble_gatts_sys_attr_set(p_ble_evt->evt.gap_evt.conn_handle, NULL, 0, 0); ... magic, I have no idea what this does yet but it works.