Adafruit
Adafruit Feather M4 Express
Best high-performance microcontroller for makers building compact, Python-powered projects.
Introducing the Adafruit Feather M4 Express, a compact microcontroller board powered by the ATSAMD51J19 chip. It features a 120MHz Cortex M4 core with floating-point support, making it ideal for demanding projects. Pre-loaded with CircuitPython, it offers an intuitive drag-and-drop interface for easy coding. With 512KB of Flash and 192KB of RAM, plus 2MB of external SPI Flash, storage is ample. Its Feather form factor ensures compatibility with a wide range of FeatherWings, expanding its capabilities. This board includes a built-in LiPo charger and robust I/O options for versatile development.
$22.95
Owner Satisfaction
4.7
/ 5
Category Rank
28
/ 1543
#28 in Development Boards
Price vs Category Average
-74%
Below average
Processor
51191204
/ ATSAMDJ ( MHz Cortex M core)
Who it's for
- Engineers building complex projects requiring high-speed computational power
- Developers seeking rapid prototyping through intuitive Python-based coding
- Makers utilizing the extensive ecosystem of FeatherWing expansion boards
Who should skip it
- Designers prioritizing long-term battery life for remote deployments
- Hobbyists working on simple projects that do not require advanced processing
- Projects needing a high density of GPIO pins for complex connectivity
Performance breakdown
Processing Power
The 120MHz Cortex M4 core handles complex calculations with impressive speed.
Ease of Programming
CircuitPython integration makes deployment intuitive for beginners and experts alike.
Expansion Versatility
The Feather ecosystem offers a massive library of plug-and-play hardware modules.
I/O Flexibility
Dual DACs and multiple ADC channels provide excellent analog signal control.
Portability
Ultra-compact footprint and integrated battery management make it perfect for wearables.
Storage Capacity
Ample external SPI Flash ensures plenty of room for data-heavy projects.
Key Specs
Processor
ATSAMD51J19 (120 MHz Cortex M4 core)
Memory
192KB RAM / 512KB Flash
External Storage
2 MB SPI FLASH chip
GPIO Pins
21 total pins
Analog Inputs
6 (12-bit ADC)
DAC Channels
2 (12-bit)
PWM Outputs
16 channels
Dimensions
50.8mm x 22.8mm x 7.0mm
Features
- Fast 120MHz Cortex M4 processor
- CircuitPython onboard for easy programming
- Feather form factor for expansion
- 2MB external SPI Flash for file storage
- Built-in LiPo charger with status LED
- UF2 bootloader for simple updates
- Dual 12-bit DACs and 6 ADC inputs
- Supports CircuitPython and Arduino IDE
What customers say
Customers overwhelmingly praise the Adafruit Feather M4 Express for its exceptional speed and ease of use, making it a premier choice for performance projects. The core satisfaction stems from seamless CircuitPython integration, which transforms the powerful ATSAMD51 processor into an accessible Python development environment for all skill levels. Users value the robust documentation and reliable support, boosting confidence in project longevity. Its standard Feather form factor ensures broad compatibility with existing accessories. While the price is premium, reviewers agree the superior performance and unparalleled ease of development fully justify the investment for demanding embedded tasks.
Know before you buy
Yes, the board is fully compatible with the Arduino IDE. You can easily switch between CircuitPython and Arduino environments depending on your project requirements.
The 2MB SPI Flash provides dedicated storage for your CircuitPython scripts, data logs, or assets, keeping them separate from the main microcontroller memory. This allows you to store larger files without consuming the board's internal flash.
Yes, it features an onboard JST connector for a 3.7V Lithium Polymer battery. It also includes a built-in charging circuit, so the battery will automatically charge whenever you plug the board into a USB power source.
Yes, the Feather M4 Express follows the standard Feather form factor. It is designed to be compatible with the wide ecosystem of FeatherWings, allowing you to easily add sensors, displays, or motor controllers.
The board is well-equipped for analog tasks, featuring six 12-bit ADC inputs for reading sensors and two 12-bit DAC channels for generating true analog signals, such as audio or precise control voltages.
The board uses a UF2 bootloader, which makes updating firmware as simple as dragging and dropping a file onto the board when it appears as a USB drive on your computer.
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