GEMMA and Trinket are great when you want a tiny, low cost microcontroller to embed in your projects. One of the tradeoffs, however, is that they can’t send data back to the computer for debugging sensor values.
For instance, you want to make a pair of Firewalker sneakers with Gemma instead of Flora, but there’s no easy way to calibrate your Velostat step sensor since you can’t see the numerical value of the reading. I recommend keeping a FLORA around for this purpose, even if you port to GEMMA later.
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.