In January 2021, the Raspberry Pi Foundation launched its first microcontroller board, the Raspberry Pi Pico. A small development board with a brand new microcontroller chip, the RP2040 was designed by Raspberry Pi in the UK.
Debugging the code inside the RP2040 chip may be done with another Raspberry Pi Pico board. A new version of the Open On-Chip Debugger (OpenOCD) is needed to use the development board as debug probe.
The source code for OpenOCD is available at the Raspberry Pi Github.
This Visual Studio Code extension contains the compiled version of OpenOCD with support for the Raspberry Pi debug probe.
Comment: The Rasberry Pi debug probe was named 'picoprobe' in the beginning. The name was changed to 'debugprobe' in the OpenOCD source code.
The server configuration for OpenOCD was changed to 'interface/cmsis-dap.cfg' and 'target/rp2040.cfg' to use the Raspberry Pi Pico as a debug probe. This was an unfortunate breaking change for the Raspberry Pi Pico debug probe caused by the Raspberry Pi Foundation.
On request of the Raspberry Pi Foundation, the name 'picoprobe' was changed to 'debugprobe' and the Raspberry Pi logo was removed.
If you have on older version of the Raspberry Pi Pico debug probe, you must update the firmware.
OpenOCD needs a few libraries to run. Install the libraries with homebrew.
If you did not install homebrew install it first.
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"brew install libusb libusb-compat libftdi hidapiIn Visual Studio Code goto extensions (shift+cmd+x), search for 'chipcode-nl' and install the extension suitable for your operating system.
The extension has paths for OpenOCD. You can use it in launch.json.
- openocd.bin
"server": "${config:openocd.bin}/openocd",
"serverArgs": [
"-f", "interface/cmsis-dap.cfg",
"-f", "target/rp2040.cfg",
"-c", "adapter speed 5000",
],Download the debugprobe UF2 file at the Raspberry Pi Pico getting started website and copy it to the Raspberry Pi Pico board.
Wiring between the debugprobe (left) and the target development board (right).
| Debugprobe (left) | Raspberry Pi Pico (right) | Description |
|---|---|---|
| GND | GND | Ground |
| GP2 | SWCLK | Debug clock |
| GP3 | SWDIO | Debug data |
| GP4 / UART1 TX | GP1 / UART0 RX | Serial port |
| GP5 / UART1 RX | GP0 / UART0 TX | Serial port |
Optional power the target development board from the USB port.
| Debugprobe (left) | Raspberry Pi Pico (right) | Description |
|---|---|---|
| VSYS | VSYS | System power |