Adafruit Feather M0 Express



  • Adafruit
Availability: In Stock

The Feather M0 Express is a Circuit Python compatible microcontroller with integrated battery charger based on the TSAMD21G18 ARM Cortex M0 processor. This board is packed with all the features you expect on a Feather including an integrated battery charger, mini-neopixel LED, and integrated 2mb flash storage.


SKU: MCR-039 Manufacturer: Adafruit Industries Mfg Part Number: 3403 Category: Tags: , , ,


The Feather M0 Express is a Circuit Python compatible microcontroller with integrated battery charger. At the Feather M0 Express’ heart is an ATSAMD21G18 ARM Cortex M0 processor, clocked at 48 MHz and at 3.3V logic. This chip has a whopping 256K of FLASH (8x more than the Atmega328 or 32u4) and 32K of RAM (16x as much)! This chip comes with built in USB so it has USB-to-Serial program & debug capability built in with no need for an FTDI-like chip.

To make it easy to use for portable projects, Adafruit has added a JST connector for their 3.7V Lithium polymer batteries and built in battery charging. The battery isn’t a requirement for using it, the board will run just fine straight from the micro USB connector or other external power sources. But, if you do have a battery, you can take it on the go, then plug in the USB to recharge. The Feather will automatically switch over to USB power when its available.

The Feather M0 Express uses the extra space left over to add a Mini NeoPixel, 2 MB SPI Flash storage and a little prototyping space. You can use the SPI Flash storage like a very tiny hard drive. When used in CircuitPython, the 2 MB flash acts as storage for all your scripts, libraries and files. When used in Arduino, you can read/write files to it, like a little datalogger or SD card, and then with our helper program, access the files over USB.

Easy reprogramming: the Feather M0 comes pre-loaded with the UF2 bootloader, which looks like a USB storage key. Simply drag firmware on to program, no special tools or drivers needed! It can be used to load up CircuitPython, PXT MakeCode or Arduino IDE (it is bossa-compatible)

Comes fully assembled and tested, with the UF2 USB bootloader. We also toss in some header so you can solder it in and plug into a solderless breadboard.


  • Dimensions: 51 x 23 x 8mm (2 x 0.9 x 0.28\\\")
  • ATSAMD21G18 @ 48MHz
  • 256KB of FLASH + 32KB of RAM
  • Hardware Serial, hardware I2C, hardware SPI support
  • Power/enable pin
  • 4 mounting holes
  • Weight: 5g
  • 3.3V logic and power
  • 3.3V regulator with 500mA peak current output
  • USB bootloader and serial port debugging
  • Built in 100mA lipoly charger with charging status indicator LED
  • GPIO pins with multiple capabilities

Package Contents

  • 1 x Adafruit Feather M0 Express
  • 2 x 16 Pin 2.54mm Pitch Header

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  Difficulty Level

Soldering Skill: Beginner
Prototyping Skill: Beginner
Programming Skill: Beginner

  Product Certifications

  Product Attributes

Weight: 15 g
Logic Voltage:








  Warranty Policy

This product has a 30 Day Warranty from the date of delivery. The item must not be modified, abused, incorrectly hooked up, or used for purposes outside the original scope of design.

  Return Policy

This product is returnable Within 14 Days of delivery for a store credit. Item must be unopened, unused, and in re-saleable condition.

More Information:
For more information on our Warranty and Return Policies, please consult our   Terms of Service


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