3403: Adafruit Feather M0 Express - ATSAMD21 Cortex M0


We love all our Feathers equally, but this Feather is very special. It's our first Feather that is specifically designed for use with CircuitPython! CircuitPython is our beginner-oriented flavor of MicroPython - and as the name hints at, its a small but full-featured version of the popular Python programming language specifically for use with circuitry and electronics.

That doesn't mean you cant also use it with Arduino IDE! At the Feather M0's heart is an ATSAMD21G18 ARM Cortex M0+ processor, clocked at 48 MHz and at 3.3V logic, the same one used in the new Arduino Zero. 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.

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. Lipoly battery and USB cable not included (but we do have lots of options in the shop if you'd like!)

Please note, CircuitPython does not come preloaded. See the full user guide linked below for instructions on installing it.


Manufacturer Adafruit Industries LLC
Category Open Source MCU Platforms
Eval Board Part Number 1528-2126-ND
Eval Board Supplier Adafruit Industries LLC
IDE Arduino IDE, with Software Add-on
Speed 48 MHz
Bits 32 Bit
Memory, Flash/RAM 256 kB + 2 MB / 32 kB
Digital I/O 20 I/O, 19 PWM
Interface I²C x1
SPI x1
USB Device
Analog Outputs (DACs) 1 x 10 Bit
Analog Inputs (ADCs) 6 x 12 Bit
DMA Channels 12
Features 1 x NeoPixel Output
Battery Charger, LiPo
Feather Compatible
Power/Enable Pin
Real Time Clock
Temperature Sensor
Radio -
Interrupt Pins 20
I/O Voltage 3.3 V
Voltage In 3 ~ 6 V
Touch Sensing Pins 6
Program/Debug Interface USB Type-Micro B
Area 1161² mm, 1.8² In
Main I.C. Base Part ATSAMD21
Design Author Adafruit
Date Created By Author 2017-02
Date Added To Library 2019-12

Eval Board

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Quantity Available: 6