Pay in installments of $5.03 with
,
and
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Aug 26 - Aug 31
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
Adafruit Feather M4 Express - Featuring ATSAMD51 Cortex M4#3857 It's what you've been waiting for, the Feather M4 Express featuring ATSAMD51. This Feather is fast like a swift, smart like an owl, strong like a ox bird (it's half ox, half bird, OK?) This feather is powered by our new favorite chip, the ATSAMD51J19 with its 120MHz Cortex M4 with floating point support and 512KB Flash and 192KB RAM. Your code will zig and zag and zoom, and with a bunch of extra peripherals for support, this will for sure be
#3857
It's what you've been waiting for, the Feather M4 Express featuring ATSAMD51. This Feather is fast like a swift, smart like an owl, strong like a ox-bird (it's half ox, half bird, OK?) This feather is powered by our new favorite chip, the ATSAMD51J19 - with its 120MHz Cortex M4 with floating point support and 512KB Flash and 192KB RAM. Your code will zig and zag and zoom, and with a bunch of extra peripherals for support, this will for sure be your favorite new chipset.
And best of all, it's a Feather - so you know it will work with all our FeatherWings! What a great way to quickly get up and running.
The most exciting part of the Feather M4 is that while you can use it with the Arduino IDE - and it's bonkers fast when you do, we are shipping it with CircuitPython on board. When you plug it in, it will show up as a very small disk drive with main.py on it. Edit main.py with your favorite text editor to build your project using Python, the most popular programming language. No installs, IDE or compiler needed, so you can use it on any computer, even ChromeBooks or computers you can't install software on. When you're done, unplug the Feather and your code will go with you.
Here are some of the updates you can look forward to when using Feather M4:
- 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
- ATSAMD51 32-bit Cortex M4 core running at 120 MHz, 32-bit, 3.3V logic and power
- Hardware DSP and floating point support
- 512 KB flash, 192 KB RAM
- 2 MB SPI FLASH chip for storing files and CircuitPython code storage.
- 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
- Built in crypto engines with AES (256 bit), true RNG, Pubkey controller
- Tons of GPIO! 21 x GPIO pins with following capabilities:
- Dual 1 MSPS 12 bit true analog DAC (A0 and A1) - can be used to play 12-bit stereo audio clips
- Dual 1 MSPS 12 bit ADC (6 analog pins some on ADC1 and some on ADC2)
- 6 x hardware SERCOM - Native hardware SPI, I2C and Serial all available
- 16 x PWM outputs - for servos, LEDs, etc
- I2S input and output
- 8-bit Parallel capture controller (for camera/video in)
- 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 M4 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 M4 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 or Arduino IDE (it is bossa-compatible)
Comes fully assembled and tested, with the UF2 USB bootloader. We also toss in some headers 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!)
Features
- Product Dimensions: 51.0mm x 22.8mm x 7.0mm
- Product Weight: 4.8g
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.0 ★★★★★
Based on 13 reviews
Sort
Product Reviews
★★★★★ 5
Love these socks!
The wife struggles with socks. She only like the Nike ones, then they discontinued them, so had to start the search again! Found these, they are expensive just like the Nike, but the size is true, they look great, they are super soft and stretchy. They are light weight and breathable and seem to wick away moisture. She loves these!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on November 18, 2025
★★★★★ 5
I stay on your foot they don’t slip in your shoe
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
This is the only socks I wear Under Armour because they stay in place I wear a size 8, but they’re more comfortable with a large instead of a medium, but I wear both because I have them already and you can pull them to stretch them out a little bit
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 12, 2026
★★★★★ 5
Great fit, truly doesn’t slide off heel
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium, Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
I’ve scoured all the lands looking for a no-show sock that was 1) thin, 2) quality, soft, breathable material, 3) didn’t dig into my feet/heels, 4) doesn’t shrink, and most importantly 5) stays on the back of my heel without a bulky non-slip rubber piece and these check all the boxes! Perfect for low profile women’s work shoes like Keds, etc. Not low enough for most flats though. I wear a women’s size 9.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 19, 2025
★★★★★ 5
So good - I’m buying MORE.
Number of Items: 3, Color: White (3-pairs), Size: Medium
I’m gonna give you more detail than you need about why I’m buying these socks again.
I’ve been the mom of girl athletes. I’ve been a model and a fashion director. I’ve worn every brand of shoe on the planet and never found a shoe that did NOT find a vulnerable spot on my foot to rub raw. Even my beloved white Jack Purcell sneakers.
With that said - I don’t like socks. I’ve bought a TON of them in 35+ years.....all major brands.
They shift. They lose their shape. They get holes in them and wear out too fast. Not these.
I retired this year, and knowing I’d be in sneakers a lot, traveling, sightseeing ......
I bought these 6 months ago and have worn them constantly. I’ve traveled with them. I’ve washed them in hot water and bleach.
The socks are like brand new. They are exactly the right cut so as not to be seen in a basic sneaker. The little silicone patch on the heel stays put. Not once have I had to dig down into my shoe and pull the sock back up. The socks have stayed soft and EXACTLY the same as the day they were new.
Like I said - I am back to buy them again. Great quality!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 20, 2021
★★★★★ 5
No slip low socks
Number of Items: 3, Color: Black/White (3-pairs), Size: Medium
Perfect! ❤️ these!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 16, 2026