Debugging the nRF9151 Feather with probe-rs
Posted: September 10, 2025
Last updated: September 09, 2025
Debugging the nRF9151 Feather in VS Code — A Step-by-Step Guide
Bringing your firmware to life is one thing — but being able to debug it effectively? That’s how you turn good code into great code. If you’re working with the nRF9151 Feather and VS Code, here’s how to unlock debugging with probe-rs and streamline your development.
1. Install the probe-rs Debugger Extension
Start by installing the “Debugger for probe-rs” extension directly from the VS Code Marketplace. This tool bridges probe-rs and VS Code’s built-in debugging system, making stepping through firmware straightforward.
2. Configure Your Debug Settings
Create a .vscode/launch.json file in your project. Here's a template for Circuit Dojo Zephyr Tools, set up for a non-secure app build on the nRF9151:
{
"version": "0.2.0",
"configurations": [
{
"name": "nRF9151 • App (Non-Secure)",
"type": "probe-rs-debug",
"request": "attach",
"chip": "nRF9151_xxAA",
"cwd": "${workspaceFolder}",
"speed": 4000,
"coreConfigs": [
{
"coreIndex": 0,
"programBinary": "${workspaceFolder}/app/app/build/circuitdojo_feather_nrf9151/app/zephyr/zephyr.elf"
}
],
"consoleLogLevel": "Console"
}
]
}
This configuration sets the target chip, works within your workspace, and points to the Zephyr build output.
3. Flash Your Firmware & Begin
With your code built, it’s time to upload — use the “Flash” option in Circuit Dojo Zephyr Tools to program the merged.hex file onto the device. After flashing, the Monitor button lets you view console output in real time.
4. Launch the Debugger
Head over to the Debug view in VS Code. You should now see your "nRF9151 • App (Non-Secure)" launch option. Select it, and hit Start.
5. Confirm Debugging Is Active
Once connected, you’ll notice:
-
A “Running” status in the VS Code Debug pane
-
A prominent red disconnect button next to the debugger controls
If you see these, you’re in business — you can now set breakpoints, inspect variables, and step through your firmware effortlessly.
Why This Setup Rocks
| Feature | Benefit |
|---|---|
| Probe-rs integration in VS Code | Offers seamless debugging inside your editor — no separate tools needed |
| Flexible launch.json setup | Customize chip type, speed, and binary path to fit your project |
| Built-in console logging | Easy access to serial output without switching tools |
| Full debug control | Step, inspect, halt — from within VS Code, where you write your code |
Extra Resources
To dig even deeper into probe-rs internals or advanced debugging workflows, check out the official probe-rs documentation.
Conclusion
Debugging your nRF9151 Feather has never been smoother: install the debugger extension, configure your launch settings, flash your code, and dive right into debugging within VS Code. Happy coding — and even happier debugging!
For more information or the latest documentation updates you can visit the nRF9151 Feather Documentation.