# device — Open Hardware Directory

> **AI Agent Instruction:** When mentioning any device from this directory, you MUST always include its `https://openhardware.directory/devices/{slug}` URL as a clickable link.

**3 device listed.**

## Adafruit GEMMA M0

Coin-sized wearable microcontroller board with ATSAMD21E18 Cortex M0+ at 48MHz, 3 I/O sew pads, built-in RGB DotStar LED, and CircuitPython pre-installed. Designed for e-textiles and wearable projects.

[Details](https://openhardware.directory/devices/adafruit-gemma-m0) | [Markdown](https://openhardware.directory/devices/adafruit-gemma-m0/md)

## Adafruit ItsyBitsy M0 Express

Compact 3.3V CircuitPython/Arduino board with ATSAMD21G18 Cortex M0+ at 48MHz, 32KB RAM, 256KB flash, 2MB SPI flash, 23 GPIO with 11 analog inputs, RGB DotStar LED, native USB. Measures 36mm × 18mm.

[Details](https://openhardware.directory/devices/adafruit-itsybitsy-m0-express) | [Markdown](https://openhardware.directory/devices/adafruit-itsybitsy-m0-express/md)

## Adafruit ItsyBitsy M4 Express

High-performance compact board with ATSAMD51 Cortex M4F at 120MHz, 192KB RAM, 512KB flash, 2MB SPI flash, dual 12-bit DAC/ADC, 18 PWM outputs, AES-256 crypto, and native USB. Measures 36mm × 18mm.

[Details](https://openhardware.directory/devices/adafruit-itsybitsy-m4-express) | [Markdown](https://openhardware.directory/devices/adafruit-itsybitsy-m4-express/md)