The Feather [M0] development boards have so much going for them with a beefy 32-bit processor running at a respectable clock speed (48 MHz) that is also loaded with storage (256k flash + 32k ram). The best part about using these boards is that the code running on them can be executed in full debug mode. A gdb client can be used to stop, step, and print values of variables. Adafruit’s latest tutorial will walk you through the Feather M0 setup for JTAG debugging on OS/X.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.