nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

Menon — Fri, 23 Aug 2024 12:26:29 GMT

Hello,

I am unsure what might be going wrong here, but I will try to address a few things you might need to check:

Try changing the USB cable and USB port. Some cables only support power and not data transfer. If you are using a USB hub, try connecting directly to a PC USB port.
Ensure that the DK is properly powered.

Review the following Segger articles to see if they resolve the issue:

If none of these solutions help, please upload a picture of your DK and setup. I will take a look to see if there is any issue with the setup or anything unusual with the DK.

Kind regards,

Abhijith

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

craig.goldman — Thu, 22 Aug 2024 16:10:58 GMT

I tried connecting to debug USB and holding reset while enabling power using switch. The PC no longer recognizes a serial port attached to the debug USB so I can't tell if BOOTLOADER sends any text.

I can download new code via nRF USB using mcumgr.
The board is not dead, but there is no communications through the normal debug USB.

I tried activating J-Link Commmand V7.96J while connecting to debug USB. It said "No probes connected via USB." No emulator was found using TCP/IP.

The cable in the picture has standard JTAG "Berg" connectors with socket spacing 0.1"x0.1". I have several of these cables. The10-pin "Debug Out" and "Debug In" on the nRF52840 DK has a smaller connector (I do not know type) with pin spacing of ~1.27mm by ~1.27mm. I would like to purchase a compatible cable but do not know where.

-Craig Goldman

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

Menon — Wed, 21 Aug 2024 15:04:16 GMT

[deleted]

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

Menon — Wed, 21 Aug 2024 15:03:01 GMT

Hello,

I’m not sure what happened here. Just to confirm, I followed the DevAcademy steps and completed the DFU via USB. When I reconnected the debug ports, I was able to see the device in VSCode and the Device Manager (as JLink). Can you communicate with your DK via nRF USB using mcumgr? If so, try uploading a different binary file to the DK and see if that works.

Could you also check what happens if you hold the IF BOOT/RESET button while powering the DK off and back on using the power switch (SW8)? Does it show up as BOOTLOADER on your computer?

If it does show up as BOOTLOADER, try pasting the Interface MCU firmware (JLink-OB-SAM3U128-V2-NordicSemi 170724.bin) that you can download from here. After a few seconds, power cycle the DK without holding IF BOOT/RESET and see if it works now. Please note that if you have a newer version of the DK (this can be identified on the white sticker), this method might not work. Let me know if it works or not

[quote user="craig.goldman"]I do not have a 10-pin serial cable with the small female connector which can plug into P19. Do you know if Digikey or someone else sells this type of cable?[/quote]

I don’t have a specific website recommendation for purchasing it. (see the screenshot, for reference)

[quote user="craig.goldman"]If I acquire the cable, does the other end plug into P18 of the "bad" board?[/quote]

Yes, please check the Debug Out and Debug In connections.

Kind Regards,

Abhijith

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

craig.goldman — Mon, 19 Aug 2024 16:28:33 GMT

I do not have a 10-pin serial cable with the small female connector which can plug into P19. Do you know if Digikey or someone else sells this type of cable?

If I acquire the cable, does the other end plug into P18 of the "bad" board?

Once the two boards are connected, is there a way to re-program the onboard debugger? Is there something else which should be done? Is there documentation on this entire process?

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

Menon — Mon, 19 Aug 2024 13:31:34 GMT

Hello,

I'm not entirely sure, but the issue might be due to the onboard debugger being compromised during the DFU process. If you have another DK, you can try using it as an external debugger to access the non-working board. Connect the Debug Out (P19) of the DKs to each other using a 10-pin Serial Wire Debug (SWD) cable.

Kind Regards,

Abhijith

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

craig.goldman — Sat, 17 Aug 2024 23:33:08 GMT

One more piece of information. I'm not sure the reset button has any effect on the running program.

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

craig.goldman — Sat, 17 Aug 2024 23:27:50 GMT

nrfjprog --recover returns... ERROR: No debuggers were discovered.

No devices show in nRF Programmer app within nRF Connect for Desktop.

I double-checked with a different development board; that board shows up in nRF programmer.

Any other thoughts?

RE: nRF52840DK stopped connecting in intermediate course lesson 8 exercise 2

Menon — Fri, 16 Aug 2024 11:33:13 GMT

Hello,

[quote user=""] Have I bricked the DK following the lesson8 instructions?[/quote]

It seems that your nRF52840 DK is still operational but is not being detected by the PC after performing the DFU over USB. Although the device appears to be functioning correctly (as indicated by LED1 blinking), it may not be exposing the expected USB interfaces.

Try resetting the device and check if it can be accessed using nrfjprog commands. For example, you could run nrfjprog --recover from the command line and review the output. Also, see if the device appears in the nRF Programmer app within nRF Connect for Desktop.

Kind Regards,

Abhijith