The Adafruit Gemma M0 is a super small microcontroller board, with just enough built-in to create many simple projects. It may look small and cute: round, about the size of a quarter, with friendly alligator-clip sew pads. But do not be fooled! The Gemma M0 is incredibly powerful! Adafruit took the same form factor they used for the original ATtiny85-based Gemma and gave it an upgrade. The Gemma M0 has swapped out the lightweight ATtiny85 for a ATSAMD21E18 powerhouse. The Gemma M0 will super-charge your wearables! It's just as small, and it's easier to use, so you can do more. The most exciting part of the Gemma M0 is that while you can use it with the Arduino IDE, it is shipped with CircuitPython on board. When you plug it in, it will show up as a very small disk drive with main.py on it. Edit main.py with your favorite text editor to build your project using Python, the most popular programming language. No installs, IDE or compiler needed, so you can use it on any computer, even ChromeBooks or computers you can't install software on. When you're done, unplug the Gemma M0 and your code will go with you.
Same size, form-factor, and pinout as classic Gemma. Three big-hole sew-pads can be used for conductive thread or alligator-clips for fast prototyping. Each I/O pad can be used for 12-bit analog input, or digital input/output with internally connected pullups or pulldowns
256KB Flash - 8x as much as 8 KB on ATtiny85, 32 KB RAM - 64x as much as 512 bytes on ATtiny85
48 MHz 32 bit processor - 6x as fast as ATtiny85 (not even taking into account 32-bit speedups)
Native USB supported by every OS - can be used in Arduino or CircuitPython as USB serial console, Keyboard/Mouse HID, even a little disk drive for storing Python scripts. (ATtiny85 does not have native USB)
Can be used with Arduino IDE or CircuitPython. Built in RGB DotStar LED