# 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.

**2 device listed.**

## Adafruit METRO M0 Express

Arduino Uno-compatible development board powered by ATSAMD21G18 Cortex M0+ at 48MHz with 256KB flash, 32KB SRAM, 2MB SPI flash, and CircuitPython pre-loaded. Features Arduino shield compatibility and native USB.

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

## Adafruit Grand Central M4 Express

Arduino Mega-form-factor board with ATSAMD51P20 Cortex M4F at 120MHz, 1MB flash, 256KB RAM, 8MB QSPI flash, 70 GPIO pins, SD card slot, 8 SERCOM, 22 PWM outputs, dual DAC/ADC, AES-256, and native USB.

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