Problems using nRFConnect with nRF52840 Dongle - No connection

[daubsi]

My nRF52840 arrived yesterday and I started playing around with it. It is immediately recognized y nRFConnect v3.5 BLE App v2.4.0. The firmware on the device is 4.1.2 Jul 14th 2020.

I am reproducing exactly this example How to use nRF52840 USB Dongle and nRF Connect for emulating a BLE peripheral

The advertised device can be found on iOS's nRF Connect App as well as with Android. The advertised name of the nRF52 is correctly received. However neither can I connect nor read the advertised services. Both apps show "No service" in the pre-connection phase. When I try to connect with iOS I immediately get the following error:

As you can see the smart phone seems to be "somewhat" connected (background of picture). The app on the phone still says "Connecting...". Some seconds later the connection terminates.

On Android I get "Error 133 (0x85): GATT Error" but nothing more.

The behavior is consistent whether running the nRF Connect tool on Linux or on Windows. The error is the same.

I also tried adding a HRS in the tool and use the nRF Toolbox on the phone to see whether this works. Here, the nRF52840 isn't even found but the app just said "Scanning".

What am I missing?

[Simonr]

Hi

Thank you for the update. I got my hands on an iPhone and tested myself. It seems like the latest Bluetooth Low Energy application has a bug, where it won't respond to the connection that the iPhone initiates for some reason. I have reported this internally, and we are looking into it. Thank you for notifying us about this! 

What iPhone model are you seeing this issue in?

As for the Android issue, I would need to know what Android device and Android version this is to help you further. I think it should work if you retry a few times, as Error 133 is rather common in some Android devices.

You can try programming the "default" ble_app_hrs peripheral example in our SDK onto your Dongle, as that should work as intended and lets you read battery level + heart rate as well.

Best regards,

Simon

[daubsi]

Hi Simon, thanks for the update. Glad you could trigger the error as well so it wasn't just me ;-) I am using an iPhone 11 Pro Plus, latest iOS 13.6.1. The same prob also shows up on iPhone 7 and my old Android 5 tablet. (thats an rather old rebranded Lenovo/Medion tablet). I'd like to add that a friend of mine tried the same experiment last night with his nRF DK52 and it worked perfectly! No errors here! (I assume he has the lastest nRFConnect app version as well, as it auto-updates?).

I didn't have time to test it with my nRF DK52 yet. Also, in another post I mentioned that the iOS nRF Connect seems to be rather laggy for me in contrast to the variant on Android (the above mentioned Android 5), where the UI was responsive, quick and accurate. I'll try flashing the hrs app as well. I am a little bit worried to do that correctly as I read I must not overwrite the bootloader. So.. do I need to use the Programmer app or can I flash it via SES, just like I do it for the nRF52 DK

[Simonr]

Did your friend use an iPhone as well? I saw the same error when testing on an nRF52840 DK, but I'll test on an nRF52 DK for good measure as soon as I can get my hands on an iPhone again. We're using an iPhone 11 with iOS v13.6.

You can follow our Dongle Programming tutorial if you're uncertain on the procedure of how you should program it. In the tutorial you can also find a chapter on how to recover it if you're unintentionally erase the bootloader.

Best regards,

Simon

UPDATE: I think your friend must be using something else than an iPhone or an older version of the Bluetooth Low Energy app when testing, as the nRF52(832) DK shows exactly the same error as well on my side.

[daubsi]

He was using a Google Pixel 3 device (Android)! I'll ask for the details!