Dongles getting bricked after PC restart

[Mike Mazowski]

Hi,

I use dongles with custom application that combines Thread and CDC ACM. The application works fine, but after restarting PC several dongles with this application stopped working.

I can still enter bootloader mode by pressing reset button and can still successfully flash default nRF Connect BLE software.

With my application, when dongle is plugged in, it is no longer detected as CDC ACM port, all LEDs seem to blink periodically for a fraction of a second, but are very dim.

Is there a way to revive these dongles?

Awaiting Yours.

[Jørgen Holmefjord]

Hi,

If you are able to flash the dongle, it's not "bricked". Sounds like there is some issue with enumerating the device on the PC. Have you tested it on multiple PCs?

Which OS are you running?

The application might detect an error and put the device in error handler (which again would reset the device if DEBUG flag is not set).

Best regards,
Jørgen

[Jørgen Holmefjord]

It could be related. Are you able to get the application working again by plugging the dongle out and in again?

Can you provide the application that you are running for us to try to reproduce the issue?

[Mike Mazowski]

No, after the issue occurs for the first time I was not able to get it to successfully run the application again.

The application for Dongle is attached as archive.

Project located under "examples\thread\cli\usb_bootloader - OG\pca10056\blank\ses".

[Jørgen Holmefjord]

I'm not able to reproduce this issue. Can you upload a precompiled hex-file that I can test with?

[Mike Mazowski]

Hex file with which the issue occurred is attached.

The PC application has DTR and RTS flow control enabled.

[Jørgen Holmefjord]

I'm still not able to reproduce the issue with your hex-file. Did you flash the application with nRF Connect programmer app? Did you make any modifications to UICR registers on the dongle? If the LEDs are lit but very dim, it sounds like a power issue, or you could have modified the UICR to output lower GPIO voltage (this tutorial is great for detailed information about the dongle).

[Mike Mazowski]

Yes, application is flashed via nRF connect. No modification to UICR registers were made. LEDs are dim as in have very low duty cycle. They blink approximately once a second, which looks like the program is restarting.

On my observation the issue has only occurred once the PC application came in. 

If You are interested in looking through application (it is very short), I can submit visual studio solution or just source files.

[Jørgen Holmefjord]

Ok, please provide PC application. Do you have the possibility to connect a debugger to the dongle, to check if any error codes are reported in the firmware?

[Jørgen Holmefjord]

Ok, please provide PC application. Do you have the possibility to connect a debugger to the dongle, to check if any error codes are reported in the firmware?

[Mike Mazowski]

The application is attached.

In file FirmwareDistibutionManager.cpp change otiOpenCOMPort("\\\\.\\COM3"); to whichever COM port Dongle is referring to.

The issue occurred when program did not exit the loop below opened COMPort and application was terminated through editor.

[Mike Mazowski]

Forgot to mention, that I do not have a debugger to see error codes.

[Jørgen Holmefjord]

What do you mean by this?

Mike Mazowski said:

application was terminated through editor

 Do you do anything specific to make the issue appear? I ran the application and restarted the computer, but I'm still not able to reproduce it.