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CircuitPython 4.1.0 Beta 0 Released!
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CircuitPython 4.1.0 Beta 0 Released!

by tannewt on Thu Jun 13, 2019 8:14 pm

From the GitHub release page:
4.1.0's biggest feature is speed! General execution of Python should be 2-5x faster and display refreshing will be faster as well.

This is the first beta version for testing. It shouldn't break any code compatible with previous 4.x releases. Please use the latest 4.x stable release (available from the new website!) when first starting with CircuitPython. It is stable.

Download it now from See here for the full release notes.

Over 50 boards are now supported by CircuitPython 4.1.0. Check out the new page for full list of all available versions.

It's not too late to contribute to CircuitPython! Check out this guide for details. We're always looking to improve and expect many stable releases in the 4.x line to happen through the summer. Subscribe to the Python for Microcontrollers newsletter on for the latest news for all things Python.
Downloads are now available from! This site makes it much easier to select the correct file and language for your board. The downloads page is here.

To install follow the instructions in our new Welcome to CircuitPython! guide. To install the latest libraries, see this page in that guide.

Try the latest version of the Mu editor for creating and editing your CircuitPython programs and for easy access to the CircuitPython serial connection (the REPL).

New Fixes and Features since 4.0.1
  • 2-5x execution speedup thanks to MicroPython configuration change. Thanks to @dhalbert and @shazz
  • Display refresh now tracks dirty areas and only refreshes them. This drastically reduces the amount of data to send to displays and therefore speeds them up. Thanks to @tannewt
  • Added ps2io module for SAMD51s. Thanks to @elvis-epx
  • Group objects are now iterable and have index and remove methods. Thanks to @tannewt
  • make stubs can now be used to make pyi stubs for native modules. Thanks to @jreese
  • Enable WaveFile sample rates above 2 ** 16. Thanks to @C47D
  • Fix mistaken Group GC. Thanks to @ATMakersBill and @dhalbert
  • Fix button miss with gamepadshift. Thanks to @kattni, @makermelissa and @deshipu
  • Doc updates. Thanks to @jpecor and @tannewt
New Boards
Thank you to all who used, tested, contributed, helped out, and participated on GitHub and/or Discord:
@adafruit, @ATMakersBill, @baorepo, @C47D, @deshipu, @dhalbert, @elvis-epx, @jpecor, @jreese, @kattni, @ladyada, @madbodger, @MakerMelissa, @matt-land, @MikeBarela, @Mr. Certainly, @mrmcwethy, @ntavish, @ptorrone, @shazz, @siddacious, @sommersoft, @tannewt, and surely more we have missed. Join us on the Discord chat to collaborate.

Documentation is available in

Here are all the changes since 4.0.1.

This release is based on MicroPython 1.9.4 @25ae98f. Support upstream MicroPython by purchasing a PyBoard (from Adafruit here).

Check out this guide for info on common problems with CircuitPython. If you are still having, then post to the Adafruit Support Forums and join Discord.

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Please be positive and constructive with your questions and comments.