GEMMA M0 Development Board Adafruit GEMMA M0 Development Board is easy to use microcontroller board for a wearable electronic platform. This bite-sized tiny wearable platform board comes in a 1.1'/28mm diameter and 0.28'/7mm thick form factor with alligator-clip sew pads. The GEMMA M0 is powered by ATSAMD21E18 32-bit Cortex M0+ and can be used with Arduino IDE or Adafruit's CircuitPython. This development kit offers 256KB Flash, 32 KB RAM, and a native USB supported by every OS. The GEMMA M0 features an On/Off switch, reset switch, JST battery connector, and built-in full RGB DotStar LED.