nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

Simonr — Fri, 03 Apr 2020 07:24:30 GMT

First of all, I want to apologize sincerely. It seems like this case fell through the cracks, as it hasn't been any updates on the case internally. I am so sorry about this, as this shouldn't happen.

On the other hand, I'm really glad that you were able to figure it out on your own, and I want to thank you for sharing your solution with us. I have reported this internally, and we will hopefully find a fix to implement in a future nRFConnect release.

Best regards,

Simon

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

rodims — Thu, 02 Apr 2020 18:59:49 GMT

After a long time of pain I found out, what caused the problem in the first place.
In previous tests last year I already removed all other USB devices from the USB bus (with the exception of the mouse), including external hubs. Now it turns out that my the Logitech mouse (10 years old) is irregularly causing this problem. Not using an external hub. I replaced it with a simple Microsoft Mouse and the problem has not been seen again since several days now.

Lets assume that the mouse (or in combinations with its driver) has some damage which causes some non-standard usb packets in the usb system. The mouse likely was not on the same internal or external hub as the devices which I used for nRF Connect "Bluetooth Low Energy" app in all my tests.

So it's still some problem with the nrfConnect tools, which likely listen to all (USB Bluetooth) devices attaching and detaching from the bus, and which crash in these special (non-reproducible) situations. The result of this crash then was the empty white client area of the window. That's what I analyzed so far last year.

I didn't have to touch or move the old mouse for the problem to occur, but it also happened occasionally when I moved the mouse.

So while this (assumed) bug is still present in the nrfConnect framework, this case can be closed, at least for me.

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

Simonr — Mon, 27 Jan 2020 09:52:12 GMT

Thank you so much for this thorough report I'm sorry that we haven't been able to give you an update on what is happening here, but the devs are struggling to find the reason for these crashes as well. Hopefully, the information you've provided will help them and hurry up the process so that you'll be able to run the nRFConnect apps as intended.

Best regards,

Simon

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

rodims — Fri, 24 Jan 2020 20:18:26 GMT

Hi,
I did not have the time some weeks ago to investigate this in depth due to development priorities. Nevertheless the nrfConnect, here "BlueTooth Low Energy" app is near to unusable for me.

I spent a lot of time to narrow the conditions for this problem, but it is highly unreproducible.
First to your questions:
I don't think it makes sense that you run the application on your PC for testing, if you didn't experience a problem so far. As I already said I don't expect everybody to have this problem, otherwise it would have been handled and fixed already. So yes, the problem for some reason likes to appear on my PC very often, and if you never got any report from other users, you can only try to analyze the feedback which I can give you now.
I'm quite sure that the real problem is a bug inside the nrfConnect applications / framework, so the question remains, why only I am suffering from it.
Also as a side note, I'm currently testing with nRF Connect v3.3.0, but I have the problems with all previous versions since at least 1 year.

1.) as said the problem may appear within seconds after starting e.g. the BlueTooth Low Energy app, or it may work for e.g. 30 minutes. However in average (number of starts versa running time without problem) it will be dead after lets say 5 minutes. This makes it more or less impossible to do a real work with the tool.

2. You asked for the dates of the Dongle PCA10059 and DKs. As I said the problem appears with both, so it is unlikely a problem of a certain firmware revision. Especially after many many tests I can say that the problem even appears, if I do not select a device in the Bluetooth Low Energy App.

I have other observations here. The problem is not only related to the "Bluetooth Low Energy" app. It's also present with the other apps. Namely the "Programmer" app also shows the problem. If I start both of them, AND after some time the problem appears, then BOTH applications windows are WHITE and empty. At exactly the same event time, whatever this event is.

On my home PC could enforce the problem by sending the Desktop PC into sleep mode and wake it up again (this did not work on my Office PC though). Afterwards the window content was white.

In general I conclude that the problem is more related to the framework of the nrfConnect applications. Note that the starter application (where you start the apps) never is included in these problems.

3) I tried a lot to find out whether the problem is related to the PC USB framework / stack, but I could not find an indication that USB is the source of the problem. Indeed when the problem appears, there is a sound played on the PC speaker, which sounds like my USB disconnect sound, however with several tools I verified that the "Bluetooth Low Energy" Sniffer device is always and stays connected. So the sound may come up due to some other Windows event.

I also removed all of my other USB devices with the exception of e.g. my mouse to avoid any interaction between them.
The problem also appears without all that devices.

4)
So I investigated the problem from another side, the process view. I used Sysinternals Process Explorer, but the normal windows task manager should do the same.

I found out that starting the nRFConnect v3.3.0 starts two sub processes as seen here, while starting "Bluetooth Low Energy starts the 3rd one (here selected with the tooltip showing the command line parameters used by the nrfConnect parent process.

So if now the problem appears I can see that the process related to the "Bluetooth Low Energy" app also disappears, i.e. it is killed, or more precisely "the process simply crashes".
For some reason the framework will leave the empty white window on the screen, but obviously the framework uses the window only as a container for the real app process.

With that knowledge I started a visual Studio debugger for the running "Bluetooth Low Energy" process. When it crashes the Debugger will stop and show an assembly statement where the process crashed. However I have no meaningful PDB symbol files for this crash, which is an access violation, so thats the point where I stop investigation.

Here is the Debugger output which is shown (reproducible) for this crash.

The first lines as text:

Exception thrown at 0x7B228E80 (af7bbb4e-3469-4df4-a8b9-18bca6b26dbb.tmp.node) in nRF Connect.exe: 0xC0000005: Access violation reading location 0x096F9000.

The debugger also would like to load a symbol file usb_bindings.pdb, but I cannot find something like this anywhere, so I suspect this is NOT a windows DLL, but something related to the nrfConnect application.

So that's something you could forward to your developers.
This does not yet answer the questions, what is the reason on my PC which lets the application so often run into this not properly handled condition and crash, but that's a starting point.

I still need this application urgently and would be happy to be able to use more than 5 minutes and then having to restart everything.

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

Simonr — Wed, 11 Dec 2019 09:32:53 GMT

I had a session last afternoon with testing, as well as ~2 hours this morning, and I still have not been able to recreate the white screen error by just letting the nRF52840 DK run in the Bluetooth Low Energy app. I guess we'll have to wait for a reply from the developers as I'm out of ideas on how to recreate the issue you're having, other than maybe rebooting your computer completely, to see if that helps, as my guess is that there are some conflicting files on the computer causing this. Can you post the revision and build date of your Dongle and DK (numbers below PCA1005X)?

Here's the log from this morning, where I tried letting the DK scan, connect, and advertise for some time to see if that triggered it.

08:15:51.399	Validating connectivity firmware for device with serial number 000683194832...
08:15:52.395	Connectivity firmware is valid.
08:15:52.395	Getting information from J-Link debugger...
08:15:53.883	Found device type: unknown. J-Link firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 7 2019 14:07:15.
08:15:53.884	Connectivity firmware version: 4.1.1. SoftDevice API version: 3. Baud rate: 1000000.
08:15:53.884	Opening adapter connected to COM13
08:15:54.803	Successfully opened COM13. Baud rate: 1000000. Flow control: none. Parity: none.
08:15:54.804	Reset performed on adapter COM13
08:15:55.925	Adapter connected to COM13 opened
08:15:58.837	Scan started
08:16:05.353	Connecting to device
08:16:05.821	Connected to device CD:3D:F1:F2:0C:E0
08:16:06.795	Attribute value read, handle: 0x03, value (0x): 4E-6F-72-64-69-63-5F-42-6C-69-6E-6B-79
08:16:25.545	Connection parameters updated for device CD:3D:F1:F2:0C:E0: interval 100ms, timeout 4000ms, latency: 0
08:24:48.459	Disconnected from device CD:3D:F1:F2:0C:E0, reason: BLE_HCI_LOCAL_HOST_TERMINATED_CONNECTION
09:03:19.225	Scan started
09:03:27.742	Connecting to device
09:03:28.071	Connected to device CD:3D:F1:F2:0C:E0
09:03:29.023	Attribute value read, handle: 0x03, value (0x): 4E-6F-72-64-69-63-5F-42-6C-69-6E-6B-79
09:03:47.934	Connection parameters updated for device CD:3D:F1:F2:0C:E0: interval 100ms, timeout 4000ms, latency: 0
10:05:58.163	Disconnected from device CD:3D:F1:F2:0C:E0, reason: BLE_HCI_LOCAL_HOST_TERMINATED_CONNECTION
10:06:33.387	Advertising started
10:23:13.089	Advertising stopped

Best regards,

Simon

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

Simonr — Tue, 10 Dec 2019 13:18:57 GMT

Hi again

I just wanted to update you on my testing today. I left the nRFConnect BLE app open during the day while going about regularly with my day, checking in once in a while that it was still up and running, and have now had it up and running without a single error for ~6 hours and 20 minutes. You can see the log below as I tried scanning a few times during the day to confirm it the app still ran as expected.

07:42:26.483	Getting information from J-Link debugger...
07:42:27.951	Found device type: unknown. J-Link firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 7 2019 14:07:15.
07:42:27.951	Connectivity firmware version: 4.1.1. SoftDevice API version: 3. Baud rate: 1000000.
07:42:27.952	Opening adapter connected to COM13
07:42:28.871	Successfully opened COM13. Baud rate: 1000000. Flow control: none. Parity: none.
07:42:28.872	Reset performed on adapter COM13
07:42:29.993	Adapter connected to COM13 opened
09:10:00.840	Scan started
09:10:05.358	Scan stopped
10:20:39.435	Scan started
10:20:41.285	Scan stopped
13:15:55.199	Scan started
13:15:56.503	Scan stopped
14:02:47.206	Scan started
14:02:48.244	Scan stopped

I will try again with connecting to a device and doing some other stuff tomorrow and report back. But seeing as you say it happens when you do nothing in the app, it seems more and more like the issue is specific to your computer.

Best regards,

Simon

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

rodims — Tue, 10 Dec 2019 13:16:26 GMT

I also did some short tests with my home PC (Windows 10 x64), same PCA10056 board which I used before). Just starting and connecting also does not show a problem over e.g. one hour. But I think we should not assume this problem would appear for everyone or under all conditions. It certainly needs some special condition which must apply.

An interesting test was the following. If I send my Windows (not a Laptop) into Sleep mode or Hibernate mode, then after awaking from that the problem appears ! The Window is blank, and only with Ctrl-R or restart of the BTLE app I can fix that (of course the USB connection to my then is also lost).

I tried to reproduce this on my Office PC (for which I reported the problem), but this does not cause the problem.
Sleep and Hibernate (and the detailed CPU sleep states) may behave different on different PCs, so I would not expect that they all behave the same.
However this might help to isolate the problem, if someone can reproduce it.
It strengthens a bit my suspect that the problem itself could have to to with USB, and the Nordic app to react improper to some unknown USB event in the system. In this case the problem would be part of the Firmware which is automatically programmed into the PCA10056 or PCA10059 upon first use with nrfConnect.
To repeat: on my Office PC there usually is no obvious human interaction when the problem appears. It just happens out of nothing, i.e. I assume it is caused by some Windows event.

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

Simonr — Tue, 10 Dec 2019 06:42:10 GMT

I let the nRF52840DK run for a while after I replied to you yesterday, and did not see the issue you describe in almost an hour of having the BLE app open and connected here on my side. I'll try again today to see if I'm able to recreate it while we're waiting for a reply from the devs.

Thank you for providing all the details you can think of!

Best regards,

Simon

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

rodims — Mon, 09 Dec 2019 21:01:49 GMT

Hi,

up to now I have no method to reliably reproduce the problem by a certain procedure. As said, the actual event seems to occur randomly, without any interaction by me within the app. However it occurs so frequently that I usually will have the problem after 20 minutes.

I have seen this on another Windows 10 computer already, though I did not verify how often it occurs on this one.
I would assume that "somehow" there must be something special with my computer/ configuration, because otherwise I would expect many many complaints about this issue.

Today I tested the following:

- it is sufficient to select a device / adapter which is connected via USB to the PC. No need to "Discover Devices" or start a Scan, or do anything else.

- As already described I tested alternatively with a PCA10056 (DK) and a PCA10059 (Dongle), both show the problem.

- My PC does not have a speaker, but by chance I once heard a typical windows beep in my headphones, exactly when the problem occured. So this might be either a standard beep issued by the nrfConnect BTLE app, or theoretically it could be related to USB events ? However the physical USB connection is solid, nothing detached or shaky.

Looking at the number of permutations (2 different PCs, 2 ( 3) different devices attached via USB, which all produce this problem, it seems as if this is a one time problem.

RE: nrfConnect for Desktop (Bluetooth Low Energy App) ALWAYS results in blank/white application window after some time of use

Simonr — Mon, 09 Dec 2019 09:27:01 GMT

I will forward this to the nRFConnect team, as I haven't seen a similar issue before myself. While we're waiting for a reply, can you think of anything in particular that you do every time when using the BLE app that can help to recreate this, as I haven't seen the white screen yet? I opened the Bluetooth Low Energy app 20 minutes ago and have not seen this issue as of yet. Are you able to test this on another computer to check if it might be specific to the computer you're using?

Best regards,

Simon