Mark Stevens' PicoDebugger Aims to Make PicoProbe Debugging Tidier, Neater, and More Flexible

Embedded developer Mark Stevens has put together a handy accessory for anyone working with the PicoProbe firmware for the Raspberry Pi Pico microcontroller boards: a carrier board to simplify connectivity between the debugger and the device on test.

"I am currently doing a lot of work with the Raspberry Pi Pico and NuttX," Stevens offers by way of background to the project. "The current work has been all about setting the stage for a project that will eventually connect the [Raspberry Pi] Pico W to some external hardware. Working in a small space it is important to try and keep hardware under control. Hardware debug environments can be messy with debug probes, the main development board plus additional connected hardware."

That's where Stevens' PicoDebugger carrier board comes in. During his development, Stevens has been using one Raspberry Pi Pico running the PicoProbe firmware to act as a debugger for a second Raspberry Pi Pico W on test. Offering surface-mount pads for the debugger-board and reusable female headers for the device on test, the compact carrier even breaks out the entire general-purpose input/output (GPIO) pin array — allowing the use of external hardware without removal from the debug rig.

"The PicoDebugger aims to provide the following features," Stevens explains. "Mount a Pico to act as a Picoprobe. Mount a target Pico. Optionally connect UART from the target to the Picoprobe. Reset the target board to allow programming by dragging a UF2 file to the target board. Deployment and debugging using SWD [Serial Wire Debug]. Connection to external project hardware."

To finish the project off, Stevens designed a 3D-printed stand for the PCB. "This base keeps the through hole parts from scratching [any] work surfaces," he explains, "and helps to reduce the possibility of unintended shorts on the exposed pins on the bottom of the board."

Design files for both the PicoDebugger carrier board and the 3D-printable base are available in Stevens' GitHub repository, under the permissive MIT license.