Adafruit ItsyBitsy M4


Platform Atmel SAM: Atmel | SMART offers Flash- based ARM products based on the ARM Cortex-M0+, Cortex-M3 and Cortex-M4 architectures, ranging from 8KB to 2MB of Flash including a rich peripheral and feature mix.

Microcontroller SAMD51G19A
Frequency 120MHz
Flash 512KB
Vendor Adafruit


Please use adafruit_itsybitsy_m4 ID for board option in “platformio.ini” (Project Configuration File):

platform = atmelsam
board = adafruit_itsybitsy_m4

You can override default Adafruit ItsyBitsy M4 settings per build environment using board_*** option, where *** is a JSON object path from board manifest adafruit_itsybitsy_m4.json. For example, board_build.mcu, board_build.f_cpu, etc.

platform = atmelsam
board = adafruit_itsybitsy_m4

; change microcontroller
board_build.mcu = samd51g19a

; change MCU frequency
board_build.f_cpu = 120000000L


Adafruit ItsyBitsy M4 supports the next uploading protocols:

  • atmel-ice
  • jlink
  • sam-ba

Default protocol is sam-ba

You can change upload protocol using upload_protocol option:

platform = atmelsam
board = adafruit_itsybitsy_m4

upload_protocol = sam-ba


Debugging - “1-click” solution for debugging with a zero configuration.


You will need to install debug tool drivers depending on your system. Please click on compatible debug tool below for the further instructions and configuration information.

You can switch between debugging Tools & Debug Probes using debug_tool option in “platformio.ini” (Project Configuration File).

Adafruit ItsyBitsy M4 does not have on-board debug probe and IS NOT READY for debugging. You will need to use/buy one of external probe listed below.

Compatible Tools On-board Default
Atmel-ICE   Yes


Name Description
Arduino Arduino Wiring-based Framework allows writing cross-platform software to control devices attached to a wide range of Arduino boards to create all kinds of creative coding, interactive objects, spaces or physical experiences
Zephyr RTOS The Zephyr Project is a scalable real-time operating system (RTOS) supporting multiple hardware architectures, optimized for resource constrained devices, and built with safety and security in mind