Adafruit Metro M0 Express – Designed for CircuitPython


Adafruit Metro M0 Express – Designed for CircuitPython


SKU: MCR-027 - Mfg Part Number: 3505


The Adafruit Metro M0 Express is the first version of the Metro designed for use with CircuitPython (Adafruit’s beginner-oriented version of MicroPython). But, it isn’t limited to this – it can also be programmed using the Arduino IDE as well.

Hardware-wise the Adafruit Metro M0 is based on the ARM Cortex M0+ ATSAMD21G18 and features a 48MHz clock speed, a whopping 256K of FLASH (8x more than the Uno) and 32K of RAM (16x more than the Uno). Onboard there are 25 GPIO pins, 12 of which are analog in, and one that is a true analog out. Hardware SPI, I2C and Serial are all available as well. The board runs with a 3.3V logic (Like the Raspberry Pi). Power can be sourced through the USB jack or the onboard DC barrel jack (7-9VDC).

But wait – there is more! Adafruit has also added an RGB Neopixel so you have something to program directly on board and 2MB of SPI Flash. The Flash storage is used by Circuit Python to store you scripts and libraries – but when using this with Arduino it becomes extra storage space you can use to data log.

Because this board is designed for both Arduino and CircuitPython, it does not ship with the CircuitPython environment installed – but Adafruit has an excellent tutorial to get it installed!


  • ATSAMD21G18 @ 48MHz with 3.3V logic/power
  • 2 MB SPI Flash chip
  • 32.768 KHz crystal for clock generation & RTC
  • USB native support
  • 25 GPIO pins
  • PWM outputs on almost all pins
  • 1 x 10-bit analog output (DAC)
  • Pin #13 red LED for general purpose blinking
  • Power on/off switch
  • 4 mounting holes
  • 256KB of FLASH + 32KB of RAM
  • 3.3V regulator with 500mA peak current output
  • USB bootloader and serial port debugging
  • Hardware Serial, hardware I2C, hardware SPI support
  • 6 x 12-bit analog inputs
  • Built in NeoPixel on pin #40
  • Dimensions: 71 x 53mm / 2.8 x 2.1″
  • Height (w/ barrel jack): 13mm / 0.5″
  • Weight: 20g
  • Reset button


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Only 2 left in stock (can be backordered)

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