Adafruit GEMMA M0 - Miniature wearable electronic platform

The Adafruit Gemma M0 is a compact, versatile microcontroller perfect for creating simple projects with ease. Despite its small size—similar to a quarter—it is powered by the robust ATSAMD21E18 processor. This makes it significantly more powerful than its predecessor, the ATtiny85-based Gemma.

Featuring a 48 MHz 32-bit processor, the Gemma M0 outperforms the ATtiny85 by offering a native USB interface supported by all operating systems. It can function as a USB serial console, a keyboard or mouse HID, or even as a tiny disk drive to store Python scripts. Thanks to its CircuitPython compatibility, editing code is straightforward—just modify the main.py file that appears as a small disk drive upon connection.

The board retains the classic form factor with three big-hole sew pads for conductive thread or alligator clips, enabling easy prototyping. Each I/O pad is capable of 12-bit analog inputs and digital I/O with internal pullups or pulldowns, and one pad supports true analog output, making it suitable for audio applications. With two high-speed PWM outputs and capacitive touch sensor compatibility, the Gemma M0 is perfect for driving servos and LEDs or creating responsive interfaces.

Additional features include DMA NeoPixel support, native hardware I2C or Serial connectivity, and the same reset switch layout for code restarts, ensuring compatibility with existing Arduino codes. A built-in JST battery connector allows for seamless power delivery through AAA or LiPoly batteries. Each Gemma M0 is tested and loaded with CircuitPython and example code ready for immediate use.