The Blackmagic Debug Probe, from 1bitsquared, is an embedded system debugger with fully open firmware. The Blackmagic Debug Firmware (BMF) is actively maintained through community efforts and offers debug of a growing number of MCUs. In addition to supporting many target MCUs, BMF also supports several platforms for running the firmware. One of these platforms is the WeAct Studio Blackpill F411CEU6.

While simply flashing the BMF code onto the Blackpill gives one an excellent debugger, the need to use fly-wires to connect to the device under test (DUT) can be painful. Dupont-style fly-wires are notoriously unreliable. Added to this, the BMF code is capable of driving a few status LEDs and patching these onto the Blackpill adds to the rat-s-nest and the unreliability.

The above are the reasons I designed the Blackpill Carrier Board. It adds all the status LEDs driven by the BMF code, plus it provides polarized, shrouded debug connectors for both the DUT and the Blackpill itself, should inception debugging be desired.

In addition, the carrier board has a connector that accepts a UART connection from the DUT. BMF provides a virtual comm port on the host computer for bidirectional access to the UART, obviating the need for a separate UART to USB adapter. Once more minimizing the physical connections and increasing reliability.

The Kicad design files for the carrier are available on GitHub or assembled and tested boards are available through Tindie. The Tindie page also offers the option to add a pre-flashed Blackpill and/or a set of cables for the hookup.