[ISSUE] Failed to launch OpenOCD GDB Server: Timeout

Hey Rick,

Yes I do have that bit of code (in addition to my target device, firmware version, etc).

I imported the project using Particle: Import Project but I don’t recall if I manually created any files along the way. I’ll try re-creating a new project and build from scratch and see if that fixes anything.


I made a fresh project with a very basic app and ran into the same problem. After the device is put into DFU mode and flashed, it says that the flash was successful, and immediately that error pops up.

To clarify, this is is the debugger I’m trying to use:

“name”: “Particle Debugger (argon, boron / bsom / b5som, xenon, tracker)”

I also tried a complete uninstallation of VS Code and its extensions but the problem remains. In case this may help other mac users, here are two commands that clean up some behind the scenes items:

rm -rf $HOME/Library/Application\ Support/Code
rm -rf $HOME/.vscode

To uninstall VS Code itself, just move it to Trash and download a new copy.

After a lot of other attempts around overriding links in my launch.json and settings.json proved unsuccessful, I came across the Particle Debugger accessory here: Debugger | Datasheets | Particle

Is it possible that my setup does not allow for debugging via VSCode /w the Particle Workbench extension?

I’m using a particle branded microUSB cable and the M.2 SOM Eval Board v 1.1, with a B402 chip.

Is it possible that I need extra hardware to sidestep this “Error: unable to find CMSIS-DAP device” error?

Edit → Never mind, I can use Particle: Serial Monitor and that works so this question is nonsensical

Edit #2 Came across this debugging guide pre SOM era that does seem to indicate that extra piece of hardware is needed: Device Debugging Lab | Workshops | Particle

Yes, you do need the Particle Debugger hardware. There is no debugging over USB directly, the debugger connects via the SWD/JTAG port (4) on the eval board, a micro 2x5 connector. A ribbon cable connects that to a CMSIS/DAP debugger, and then the debugger connects by USB to your computer.

You need two separate USB connections to your computer, one directly to the eval board itself, and one to the debugger connected to the SWD/JTAG port.