Locked nRF52840 DK board

[p143]

Hi All.

Practising Secure DFU, my nRF52840 DK board seems like if it is locked. Only Leds 1 and 2 are ON. The board is advertising with DEVICE_NAME=Dfu Targ and its COM serial communication is lost. If I press the reset button SW5, nothing happens. If I press the reset button (SW5) while power cycling, the board enters in bootloader mode, but appart from this, nothing seems to change. If I try to access the board via nRF Connect, when I try >Select Device my PCA10056 is not being detected. Summarizing. I need an HW full reset procedure.

Does anyone know how to do it?

Thanks for your time.

Regards

Juan

[Hung Bui]

Hi Juan, 

Could you clarify: 

- If you power on, without pressing SW5, what did the board do ? Did the board advertise as Dfu Targ ? 

- If you power on and pressing SW5, what happened ? 

- Can you reprogram the board using nrfjprog.exe  ?

- Did you modify the bootloader ? You may want to try following our guide here to test secure DFU.

[p143]

Hi Jung,

- If you power on, without pressing SW5, what did the board do ? Did the board advertise as Dfu Targ ? 

... Leds 1 and 2 are ON. The board is advertising with DEVICE_NAME=Dfu Targ and its COM serial communication is lost ,,,

- If you power on and pressing SW5, what happened ? 

... Leds 1 and 2 are ON. Led 5 gets intermittently  ON. A BOOTLOADER Folder pops  up  in my file explorer . The board keeps advertising Dfu Targ ...

- Can you reprogram the board using nrfjprog.exe  ?

.. I never used this executable to program as far. I use either SES IDE Build and Run command if I have a source file, or the  Connect from PC/ Programmer tool if I have an .hex file. Anyway, my serial connection through USB seems to be broken, so when I click the "Select Device" Tab in the Connect/Programmer tool, my PCA10056 doesn't show up anymore, so I guess that executing a nrfjprog.exe from my cmd console wouldn't work either ...

- Did you modify the bootloader ? You may want to try following our guide here to test secure DFU.

Yes I did, but always following the Step by Step Guide you mention in your link.  Everything went fine till completing Step D. Then, while trying step E, something went wrong. As suggested, I modified the DEVICE_NAME in the Secure DFU SDK example application and generated a new DFU .zip packet using the previously built (in step A) private and public keys and a new application version (number 2 now). Then I issued the command "nrfutil pkg generate --hw-version 52 --application-version 1 --application nrf52832_xxaa.hex --sd-req 0x98 --key-file private.key app_dfu_package.zip" and copied the resulting zip to my mobile. Finally, I tried to re-program the PCA10056 device through ble using the mobile nRF Tools/DFU app. After a while, the process got time-out and an error message " the Dfu Device got disconnected" kept popping up every time I tried. Finally, I tried connecting/disconnecting/power cycling and pressing all sort of buttons on the PCA10056 board, only to discover that it went apparently locked (?).

Any suggestion?

Thanks in advance for your help.

Best regards

Juan

[Hung Bui]

Hi Juan, 

Please be aware that COM serial communication and programming interface are 2 different interfaces. You still can program the board via programming interface even if you have problem with UART communication. Please install our command line tools and try nrfjprog so we have more debug information 

 The problem here is that you were using the guide for nRF52832 on a nRF52840 chip. They are not compatible. 

When you press and hold the reset button when starting the board, it's the bootloader mode of the programmer on the board, not the bootloader of the nRF52832 chip. 

If you have trouble to recover the nRF52840 (not pressing reset button when turning on the board) with nrfjprog. Please try to put the board in to bootloader mode (where you see the BOOTLOADER folder popup) and drag and drop this J-Link OB-SAM3U128-V2-NordicSemi 170724.bin file into the driver/folder.  

[p143]

Hi Hung.

I'll try your suggestion Thanks.

But meanwhile and since my final goal is being able to program an nRF52840 device through ble transport and using Secure DFU bootloader procedure, if you say that the guide I was using is for an nRF52832 device which is incompatible with an nRF52840 one, would you please tell me which guide (if there is any), or describe the procedure (if there re is none yet) we should I implement? The components I would like to program through ble are the softdevice, the MBR, the secure bootloader and the application. Using a non-secure bootloader compatible procedure would also fit me though.

Thanks

Best regards,

Juan

[Hung Bui]

Hi Juan, 

It's pretty simple to use the guide for the nRF52840. Just make sure you use the bootloader for nRF52840, the application you plan to update is made for nRF52840, and then in the .zip file generation, select the correct sd-req. 

Note that you can't update the MBR. It's the core of the updating, it can't update itself. 

First you would need to recover the chip and make sure you can reprogram it. 

[p143]

Hi Hung.

I got it 

Thanks

One last question. From this Infocenter Nordics documentation:

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it looks as if you could make mobile Secure DFU not only from nRF Toolbox app, but also from mobile Connect app (Android version 4.4 or later). Mine is v4.22.2 but I can't see where the DFU feature is allocated. Would you clarify it? 

Thanks again and,

Best regards

Juan