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,

I see, that is odd. Then the UICR should have been updated as well. Can you read out the UICR using nrfjprog.exe --readuicr uicr.hex and upload it here?

[Hinal Tailor]

Hello

I have read UICR Register you can find it from attached HEX file.

0458.uicr.hex

You can see this command "nrfjprog.exe --readuicr uicr.hex" is not found that's why I have tried "nrfjprog --readuicr uicr.hex" and it is reading UICR.

Best regards,

Hinal Tailor

[Einar Thorsrud]

Hi Tailor,

The UICR does not contain any configuration for REGOUT0, which sets the output voltage, so you need to set that. That is a bit odd as I though should have been set by the bootloader, but that may not be the case. Then, you can set via a debugger using nrfjprog like this: nrfjprog --memwr 0x10001304 --val 0x4. This will make the VDD voltage (after the high voltage regulator) 3 V after a reset.

[Hinal Tailor]

Hi Einar

 I have uploaded bootloader HEX file and set UICR . I am getting 3V at VDD_nRF pin but still not getting comport and power on LED also not blink. When I pressed RESET button it will not enter in USB DFU mode and RED led is always blinking.

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.