by Silicognition LLC

Image of Board

This board is a electrically a clone of the Adafruit Feather M4 Express, but physically optimized to fit on top of the PoE-FeatherWing, filling the empty space around the RJ45 and flyback transformer and allowing the creation of extremely compact Power over Ethernet systems.

Just like the original Feather M4 Express, it is powered by the ATSAMD51J19 - with its 120MHz Cortex M4 with floating point support and 512KB Flash and 192KB RAM. It also has 2MB of SPI flash on board. The only thing missing compared to the original is the battery charger, which was deemed expendable for Power over Ethernet systems. The board comes with a UF2 bootloader for easy Arduino and CircuitPython compatibility, and has CircuitPython with Wiznet W5500 drivers pre-installed, plus a boot.py that sets the Ethernet connection up for you!

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CircuitPython 6.2.0-beta.3

This is the latest unstable release of CircuitPython that will work with the M4-Shim.

Unstable builds have the latest features but are more likely to have critical bugs.

Release Notes for 6.2.0-beta.3

Built-in modules available: _bleio, _pixelbuf, analogio, audiobusio, audiocore, audioio, audiomixer, audiomp3, binascii, bitbangio, bitmaptools, board, busio, countio, digitalio, displayio, errno, framebufferio, frequencyio, gamepad, i2cperipheral, json, math, microcontroller, msgpack, neopixel_write, nvm, os, ps2io, pulseio, pwmio, random, re, rgbmatrix, rotaryio, rtc, sdcardio, sharpdisplay, storage, struct, supervisor, terminalio, time, touchio, ulab, usb_hid, usb_midi, vectorio

Absolute Newest

Every time we commit new code to CircuitPython we automatically build binaries for each board and language. The binaries are stored on Amazon S3, organized by board, and then by language. Try them if you want the absolute latest and are feeling daring or want to see if a problem has been fixed.

Past Releases

All previous releases are listed on GitHub, with release notes, and are available for download from Amazon S3. They are handy for testing, but otherwise we recommend using the latest stable release. Some older GitHub release pages include the same binaries for downloading. But we have discontinued including binaries as assets on newer release pages because of the large number of files for each release.


UF2 Bootloader

Latest version: v3.13.0

The bootloader allows you to load CircuitPython, Makecode, and Arduino programs. The bootloader is not CircuitPython. You can check the current version of your bootloader by looking in the INFO_UF2.TXT file when the BOOT drive is visible (FEATHERBOOT, CPLAYBOOT, etc.).

To update, first save the contents of CIRCUITPY, just in case. Then double-click the reset button to show the BOOT drive. Drag the update-bootloader .uf2 file to the BOOT drive. Wait a few tens of seconds for the bootloader to update; the BOOT drive will reappear. Check INFO_UF2.TXT to verify that the bootloader version has been updated. Then you will need to reload CircuitPython.