The Adafruit ItsyBitsy M0 Express is a compact yet powerful microcontroller board built on the ATSAMD21 Cortex M0+ running at 48 MHz. At just 1.4" × 0.7", it delivers the same capability as the Metro M0 or Feather M0 Express in a fraction of the size — perfect for shrinking prototypes into final builds.

Ships with CircuitPython pre-loaded — plug it in, edit the Python code on the drive that appears, and your project runs immediately. No IDE or compiler installation required. It also works with the Arduino IDE for C/C++ development.

Key Features

• ATSAMD21G18 Cortex M0+ – 48 MHz, 32-bit processor with 256 KB Flash and 32 KB RAM
• 2 MB SPI Flash – Onboard storage for CircuitPython code, data logging, and files
• CircuitPython & Arduino – Ships with CircuitPython; also programmable via Arduino IDE
• Native USB – Serial console, HID keyboard/mouse, MIDI, or small disk drive
• 23 GPIO Pins – 11× 12-bit analogue inputs, 1× true analogue output, 13× PWM, 7× capacitive touch
• VHigh Output Pin – Outputs higher of VBAT or VUSB; Pin 5 is level-shifted to high voltage
• DMA NeoPixel Support – Drive NeoPixels on the VHigh pin without processor overhead
• Built-in RGB DotStar LED – Plus a red Pin 13 LED for status indication
• 3.3V Logic, 48 MHz – Hardware SPI, I2C, and serial
• Automatic Power Switching – Runs from USB or battery with seamless switchover

Ideal For

• Compact CircuitPython projects — no IDE installation needed
• Shrinking Metro M0 or Feather M0 prototypes into tiny builds
• USB HID devices, MIDI controllers, and data loggers
• NeoPixel and DotStar LED projects with DMA support

Package Contents

• 1× Adafruit ItsyBitsy M0 Express (with CircuitPython pre-loaded)
• 1× Header Strip (unsoldered)

Resources

• Adafruit ItsyBitsy M0 Express Guide
• CircuitPython.org