{"title":"Adafruit METRO M0 Express - designed for CircuitPython [ATSAMD21G18]","handle":"adafruit-metro-m0-express-designed-for-circuitpython-atsamd21g18","url":"/products/adafruit-metro-m0-express-designed-for-circuitpython-atsamd21g18","description":"The Adafruit Metro M0 Express brings 32-bit ARM power to the familiar Metro/UNO shield-compatible form factor. Powered by the ATSAMD21G18 ARM Cortex M0+ processor at 48 MHz, it offers 256 KB flash and 32 KB RAM — a massive upgrade over the ATmega328-based Metro. Designed from the ground up for CircuitPython, it also works seamlessly with the Arduino IDE.\n\nWith built-in native USB, the Metro M0 Express can act as a serial device, keyboard, mouse, or MIDI controller — no FTDI chip needed. The 2 MB SPI flash storage serves as a tiny drive for CircuitPython scripts, libraries, and data files. CircuitPython comes pre-loaded and ready to go.\n\nKey Features\n\n\nATSAMD21G18 ARM Cortex M0+ – 48 MHz, 256 KB flash, 32 KB RAM, 3.3V logic\n\nNative USB – Serial, keyboard, mouse, and MIDI support with no additional hardware\n\n2 MB SPI Flash – On-board storage for CircuitPython scripts or Arduino data logging\n\n25 GPIO Pins – 12 analogue inputs, 1 true analogue output, hardware SPI, I2C, and UART\n\nUNO Shield Compatible – Standard Metro/UNO form factor for plug-in shields\n\nFlexible Power – 7–9V DC (polarity protected) or Micro USB, with auto-switching and on/off switch\n\nUF2 Bootloader – Drag-and-drop firmware updates via USB storage mode\n\nCircuitPython Pre-Loaded – Ready to code out of the box\n\nStatus LEDs + NeoPixel – Power (green), RX/TX, red LED, and an RGB NeoPixel\n\n\nIdeal For\n\nCircuitPython beginners looking for a shield-compatible board\nProjects needing more power than an ATmega328 platform\nUSB HID projects (keyboard, mouse, MIDI)\nData logging with on-board flash storage\n\n\nPackage Contents\n\n1× Adafruit Metro M0 Express (fully assembled with headers)\n4× Rubber bumper feet\n\n\nResources\n\nMetro M0 Express Guide — Pinouts, Schematics & Code (Adafruit Learn)\nUF2 Bootloader Guide (Adafruit Learn)\n","vendor":"Adafruit","product_type":"physical","in_stock":false,"options":[],"variants":[{"id":13712,"title":"Default Title","sku":"AF-3505","price":51.65,"on_sale":false,"in_stock":false,"available_quantity":0,"option1":"Default Title"}]}