Adafruit Feather M0 Express - Designed for CircuitPython - ATSAMD21 Cortex M0

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 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. Please note that while this board was our first for CircuitPython usage, better and bigger chips have come out since then! We recommend the Feather M4 for a roomy, speedy, experience. Here's some handy specs! Measures 2.0" x 0.9" x 0.28" (51mm x 23mm x 8mm) without headers soldered in Light as a (large?) feather - 5 grams ATSAMD21G18 @ 48MHz with 3.3V logic/power 256KB of FLASH + 32KB of RAM No EEPROM 32.768 KHz crystal for clock generation & RTC 3.3V regulator with 500mA peak current output USB native support, comes with USB bootloader and serial port debugging You also get tons of pins - 20 GPIO pins Hardware Serial, hardware I2C, hardware SPI support PWM outputs on all pins 6 x 12-bit analog inputs 1 x 10-bit analog ouput (DAC) Built in 100mA lipoly charger with charging status indicator LED Pin #13 red LED for general purpose blinking Power/enable pin 4 mounting holes Reset button 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.  Lipoly battery and USB cable not included (but we do have lots of options in the shop if you'd like!) Technical Details Wanna get started with this fancy new Feather? We have a full guide with details on using it with both Arduino IDE and CircuitPython. The guide also has wiring information, drivers, Fritzing objects, schematics, datasheets and more! Product Dimensions: 51.0mm x 22.8mm x 7.3mm / 2.0" x 0.9" x 0.3" Product Weight: 4.7g / 0.2oz