nRf9151 Development Kit (nRF9151DK) connection to laptop does not result in character device file creation (no /dev/ttyACM* ).

RE: nRf9151 Development Kit (nRF9151DK) connection to laptop does not result in character device file creation (no /dev/ttyACM* ).

Mariano Goluboff — Wed, 16 Jul 2025 14:55:44 GMT

What is the output when you run the command manually in the terminal? Also, what's the output of nrfutil device --version?

RE: nRf9151 Development Kit (nRF9151DK) connection to laptop does not result in character device file creation (no /dev/ttyACM* ).

dheadrick — Tue, 15 Jul 2025 21:25:23 GMT

The other 'working' devkit has now begun to behave the same way... What could be causing this? I have done nothing with GPIOs or peripherals or arranged the hardware at all (the board is on an antistatic mat and hasn't been touched since it was working).

All I have been doing is using minicom as a serial terminal, and flashing the board with our project executables using west cli commands to build and flash the board ....

When I run the west 'flash' command, I have not been providing any information on the board target (I Imagine this is determined implicitly given its the only serial device I have connected to my laptop at the time)

---

Turns out, when I use the vscode extension to flash the board, it now works !

It looks like when I use the vscode extension the flash command is:

west flash -d blahblahpath/example_programs/at_client/build --dev-id xxxxxxxxxx --erase

The command I am entering manually into my terminal is:

west flash -d blahblahpath/example_programs/at_client/build

That being said, it would be nice to know why the second command (what I have traditionally been using via cli to build and flash the board) would work intermittently , while the first command 'revived' the OB debugger and allowed my kernel cdc_acm driver to 'see' the device.

RE: nRf9151 Development Kit (nRF9151DK) connection to laptop does not result in character device file creation (no /dev/ttyACM* ).

dheadrick — Tue, 15 Jul 2025 18:20:16 GMT

After running that command with only the 'not-working' devkit plugged into my laptop, it appears the command simply times out.

That being said, after it times out, the power indicator led (LED 5) turns off, then blinks, then returns to solid green.

❯ nrfutil device x-update-debug-probe-firmware
Error: One or more update debug probe firmware tasks failed:
 * 1051251667: Timed out waiting for response from worker. (Generic)

RE: nRf9151 Development Kit (nRF9151DK) connection to laptop does not result in character device file creation (no /dev/ttyACM* ).

Menon — Tue, 15 Jul 2025 11:26:29 GMT

Hello,

Can you please try running nrfutil device x-update-debug-probe-firmware to see if updating the interface chip resolves the issue?

Kind regards,
Abhijith