Debugging embedded code is so much easier with a HW debugging probe like the J-Link or Atmel ICE. But connecting these to Feather format development boards that don’t have a debugging header means adapting the board by soldering leads to you Feather.

I use Feathers from Adafruit and SparkFun all the time, in fact most of LooUQ's embedded development for the SAMD processors is done on one of these boards. I designed the board to make embedded code debugging for LooUQ's applications easier. Instead of using a collection of modified Feather boards in our lab, I can grab any one of them, put it in my project, and start debugging.

The UXplor SWD-F strikes a balance between being as small as possible and making the 10-pin debugging header accessible. The UXplor SWD-F extends only 7mm beyond the end of your Feather development board from the end opposite the micro-USB connector. For an Adafruit Feather your footprint is 58mm long; the total length of the Thing Plus with the UXplor Feather SWD is 66mm (the Thing Plus extends on the USB end beyond Adafruit units + the 7mm for the UXplor adapter).

The UXplor SWD-F uses spring-loaded POGO pins to connect up SWIO and SWCLK to the flat surface pads exposed on the bottom of the Feathers. The UXplor is totally a passive device; there are no active components, just connectors. But since I was building it, I added a QWiiC compatible jack for attaching I2C devices with QWiiC connectors to Adafruit Feathers without a separate board during development.

Note: This product is not compatible with the Adafruit Feather M4 Express (pads located differently than M0 Feathers). A future release is planned to support both M0 and M4 Feathers from Adafruit.

Tested compatible with...

• Adafruit Feather M0 Express
• Adafruit Feather M0 Basic Proto
• Adafruit Feather M0 WiFi
• Adafruit Feather M0
• SparkFun Thing Plus (M4)

If you are using a Feather, but it doesn’t match either Adafruit or SparkFun SWIO\SWCLK pad placement there is a JST 2-pin connector to adapt to your unique needs. But let us know and maybe we can adapt the UXplor SWD-F to a larger audience. Otherwise we can sell you a JST pigtail for that need.

You can order the UXplor SWD-F with either stacking or non-stacking headers. You will also need to indicate if you are debugging Adafruit Feather or the SparkFun Thing Plus. Adafruit and SparkFun differ on where they place the SWIO/SWCLK pins.

You can also order the board with both Adafruit AND Sparkfun POGO pins, but beware. The Adafruit Feather M0 Basic Proto and the Adafruit Feather M0 Express - Designed for CircuitPython have a through-hole pad connected to ground that will short-circuit with the Thing Plus’ SWIO pad. I have tried scotch tape to insulate the ground pads, but there is a risk you will forget. You can order a combo with 2 UXplor SWD-F boards: one for Adafruit, one for SparkFun.