Unable to debug nRF52840 dongle with nRF Connect SDK and vscode

[namtab]

Hi,

I have soldered a 2x5 pin header to nRF52840 dongle, and I have connected J-Link Base into the header.

The setup works without problems if I debug Blinky example with Segger Embedded Studio and oldish nRF5_SDK_15.0.0.

But if I try to debug a similar Blinky example with nRF Connect SDK and vscode, the debugger does not break in main.

I have tried NCS v2.3.0 and v2.4.2 both in Windows and Linux (Ubuntu 20.04), but the same problem persists.

The example app is in this path: ~/ncs/v2.3.0/zephyr/samples/basic/blinky.

This is the DEBUG CONSOLE output from vscode:

JLinkGDBServerCLExe: SEGGER J-Link GDB Server V7.58b Command Line Version
JLinkGDBServerCLExe: 
JLinkGDBServerCLExe: JLinkARM.dll V7.58b (DLL compiled Nov 16 2021 15:04:27)
JLinkGDBServerCLExe: 
JLinkGDBServerCLExe: -----GDB Server start settings-----
JLinkGDBServerCLExe: GDBInit file:                  none
JLinkGDBServerCLExe: GDB Server Listening port:     38491
JLinkGDBServerCLExe: SWO raw output listening port: 2332
JLinkGDBServerCLExe: Terminal I/O port:             2333
JLinkGDBServerCLExe: Accept remote connection:      yes
JLinkGDBServerCLExe: Generate logfile:              off
JLinkGDBServerCLExe: Verify download:               off
JLinkGDBServerCLExe: Init regs on start:            off
JLinkGDBServerCLExe: Silent mode:                   on
JLinkGDBServerCLExe: Single run mode:               on
JLinkGDBServerCLExe: Target connection timeout:     0 ms
JLinkGDBServerCLExe: ------J-Link related settings------
JLinkGDBServerCLExe: J-Link Host interface:         USB
JLinkGDBServerCLExe: J-Link script:                 none
JLinkGDBServerCLExe: J-Link settings file:          none
JLinkGDBServerCLExe: ------Target related settings------
JLinkGDBServerCLExe: Target device:                 nRF52840_xxAA
JLinkGDBServerCLExe: Target interface:              SWD
JLinkGDBServerCLExe: Target interface speed:        12000kHz
JLinkGDBServerCLExe: Target endian:                 little
JLinkGDBServerCLExe: 
=thread-group-added,id="i1"
=cmd-param-changed,param="pagination",value="off"
0x00000578 in ?? ()
[New Remote target]

Thread 2 received signal SIGTRAP, Trace/breakpoint trap.
0x00000578 in ?? ()
Execute debugger commands using "-exec <command>", for example "-exec info registers" will list registers in use (when GDB is the debugger)

Does anybody have any idea what could be wrong?

[namtab]

If I flash the Blinky app hex file with Programmer (the app in "nRF Connect for Desktop"), the green led in the dongle starts blinking.
So the build is OK.
But if I do the flashing with vscode, the led does not start blinking.

[Menon]

Hello,

This might be because you have accidentally erased the bootloader. How's your dongle detected in the nRF Connect for Programmer App (can you share a screenshot)? Refer to this dongle programming tutorial, and there is a bootloader zip file provided at the end. You can try reprogramming it using an external debugger.

Kind Regards,

Abhijith

[namtab]

Thanks for the tip.
Unfortunately reprogramming the bootloader does not help with the debugging problem.

But the reprogramming is needed, if I ever want to use the Programmer again.

Whenever I flash the dongle with vscode, it erases the bootloader.

BR,

jukka

[namtab]

I found the solution for this problem.
It is the same as for this issue:
Flashing a hex file (peripheral_lbs example built with vscode using NRF connect SDK) works when flashed with NRF Connect Desktop Programmer, but does not work when flashed with vscode directly.

Thanks dhpn !

[Menon]

Hello,

I'm glad to hear that your issue has been resolved. And thanks for pointing this out; it will be useful for others who come across a similar issue.

Kind Regards,

Abhijith