nRF52840-Dongle USB DFU problem.

[Hinal Tailor]

Hello

    I want to flash my simple coap server code in nRF52840-Dongle using USB DFU mode with nRFConnect but I did not find COMPORT/ Any Jlink Device after put donge in USB DFU mode. I want to inform you that, accidentally UICR was erased and I need secure bootloader HEX file for Dongle. I also want to know that problem is in Hardware or software because when I am applying 5V to VBUS pin It will not give 3V at D+ and D- pins and internal buck regulator output is 1.8V coming.

Please provide best solution. I need to create openthread mesh network for my application as early as possible because I am working on a sharp deadline project.

Best Regards,

Hinal Tailor

[Einar Thorsrud]

Hi Hinal,

I want to inform you that, accidentally UICR was erased and I need secure bootloader HEX file for Dongle. I also want to know that problem is in Hardware or software because when I am applying 5V to VBUS pin It will not give 3V at D+ and D- pins and internal buck regulator output is 1.8V coming.

At least two things happen when you erase the UICR:

1. The bootloader start address is removed (though also the bootloader and MBR so that is not a problem in itself).
2. The REGOUT0 register that controls the output voltage out of Reg 0 is reset to the default value which is 1.8V.

So, you need to program the MBR and bootloader and UICR again. If you are able to use SWD using a J-Link Pro or similar, then you can get the hex file from the Revert to production bootloader section in the nRF52840 Dongle programming tutorial program that and you should be good after a reset. If you are not able to program via SWD due to the low VDD voltage you need to make some HW adjustments first, as described under Recover after an accidental UICR erase in the same tutorial.

Please provide best solution. I need to create openthread mesh network for my application as early as possible because I am working on a sharp deadline project.

Please create a separate question for this as it is not directly related to the programming issue (keeping separate questions in separate threads makes it easier to maintain focus).

Einar

[Hinal Tailor]

Hello

    Thank you for your response. I want to inform you that I already uploaded HEX file.

graviton_bootloader_mbr_v1.0.1-[nRF5_SDK_15.0.1-1.alpha_f76d012].hex

But I didn't get 3V at VDD_nRF pin and comport is not coming.

Thanks

Hinal Tailor

[Einar Thorsrud]

Hi Hinal,

The LD2  LED will pulsate (soft blink) read to indicate DFU mode. Is that what you see when you say "RED led is always blikning"? How have you validated that it is not in USB DFU mode?

[Hinal Tailor]

Hi

 When I am connecting Dongle with Debugger that time RED LED is pulsating (soft blink) and when I have disconnect dongle from debugger RED LED is continuously blinking. 

I have identify that nRF52840-Dongle is not in DFU mode by not getting any comport in nRF connect to flash the code.

Hinal Tailor

[Einar Thorsrud]

By red LED here you refer to LD2? And that is "hard" blinking red instead of soft blinking red? And the behavior here is dependent on only weather a debugger is connected or not?

[Hinal Tailor]

Hi

  Yes here i refer LD2 red led. Yeah that is "hard" blinking red led. Weather a debugger is not connected.    

[Einar Thorsrud]

Is it rapidly blinking, toggeling every 100 ms? That is the only thing that would make sense from what I can see from <SDK>\examples\dfu\open_bootloader\main.c. I am not ablet o see why you should get in this state though, and certainly not why having a debugger attached or not matters. Have you made any HW changes to the dongle? Which?

[senthil_kumar]

Hi 

 I am a Hinal colleague. We both are on the same project. 

Einar Thorsrud said:

Is it rapidly blinking, toggeling every 100 ms?

 Yes, LD2 led toggling every 100 ms rapidly blinking. 

Einar Thorsrud said:

Have you made any HW changes to the dongle? Which?

There are "NO" changes in the dongle.

[senthil_kumar]

Hi 

 Any update? for dongle dfu.

[Einar Thorsrud]

Hi,

This blinking would be because there is a timeout (see usage of m_dfu_progress_led_timer in examples\dfu\open_bootloader\main.c). Are you sure you did not damage anything that could explain lack of USB connectivity when soldering on wires for the debugger? It is also very odd that the behavior depends on if a debugger is attached or not. Or are you able to reproduce on another dongle?