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CIrcuitPython 6.0.0 Alpha 2 released!
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CIrcuitPython 6.0.0 Alpha 2 released!

by tannewt on Fri Jul 24, 2020 7:42 pm

From the GitHub release page:
This is the second alpha release of CircuitPython 6.0.0. It is alpha because we are planning one more API change to ulab. It is relatively stable.

Feature-wise, this stable release adds basic lower power support when in time.sleep() and initial ESP32-S2 support. The lower power work changed time keeping and may have introduced bugs. Please use 5.3.0 if you need a stable version of CircuitPython.

Download from
Downloads are available from! The site makes it easy to select the correct file and language for your board. The downloads page is here. Downloads are no longer available from the GitHub release pages because of the large number of files for each release.

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 features and improvements since 6.0.0 Alpha 1
API Changes
  • Disable socket, wiznet5k and network modules. They will be removed in 7.x in favor of networking libraries. Thanks to @tannewt
  • Add memorymonitor for memory debugging. It must be enabled on a local build. Thanks to @tannewt
  • Add .find, .rfind, .index and .rindex to bytearray for CPYTHON compatible builds. Thanks to @tannewt
  • json.load now works with any object with readinto. Thanks to @tannewt
  • Improved performance with background task rework. Now on par with 5.3.x Thanks to @jepler
  • Enable PYSTACK which separates python code state from C code state and improves memory use. Let us know if you hit a RuntimeError from an exhausted pystack. It may be too small. Thanks to @tannewt
  • ESP32S2 build can now be parallelized. Thanks to @jepler
  • ESP32S2 unique IDs are now actually unique. Thanks to @jepler
  • Fixed VectorShape non-transposed pixel placement. Thanks to @warriorofwire
  • Fixed USB starvation during long numeric calculations. Thanks to @daveputz
  • Fixed Polygon.points. Thanks to @WarriorOfWire
  • SAMD brown out levels are now configurable. Thanks to @deshipu
  • MP3 playback improvements. Thanks to @jepler
  • PulseIn fixed on SAMD. Thanks to @DavePutz
Board changes
  • Enable analogio on PewPew M4. Thanks to @deshipu
  • Seeed Wio Terminal display now init by default. Thanks to @ansonhe97
  • License documentation improvements. Thanks to @flameeyes
  • Improve generated .pyi files. Thanks to @ciscorn
  • Additional type hints to the core docs. Thanks to @dherrada
  • Documentation improvements. Thanks to AndrewR-L, @dkhawk and @dunkmann00
  • Dutch, Indonesian, Portuguese, Spanish, and Swedish translation improvements. Thanks to @bergdahl, @fede2cr, @oonid, @ryevertigo, and @wtuemura.
Full commit log is here.

Breaking changes since 5.x
  • i2cslave is now i2cperipheral and the class in it is changed as well.
  • The stop kwarg has been removed from I2C.writeto(). If no stop is desired, then use writeto_then_readfrom.
New boards since 6.0.0 Alpha 1
Known Issues
  • displayio operations that read from an SD card (e.g., OnDiskBitmap) will interfere with other SD card operations and can cause lockup. To work around this problem, do not read or write files on the SD while the display is updating, and vice versa.
  • See for other issues.
Thank you to all who used, tested, contributed since 6.0.0 Alpha 1, helped out, and participated on GitHub and/or Discord, including @ansonhe97, @arms22 @Arudinne, @bergdahl, @ciscorn, @DavePutz, @deshipu, @dhalbert, @dherrada, @dkhawk, @dunkmann00, @fede2cr, @flameeyes, @jepler, @ladyada, @oonid, @ryevertigo, @tannewt, @TinkeringTech, @warriorofwire, @wtuemura and @xiongyihui and surely more we have missed. Join us on the Discord chat to collaborate.

Documentation is available in

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

One important feature of CircuitPython is translated control and error messages. With the help of fellow open source project Weblate, we're making it even easier to add or improve translations. Sign in with an existing account such as Github, Google or Facebook and start contributing through a simple web interface. No forks or pull requests needed!

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

Builds are no longer stored as assets on this release page, because there are too many of them. Please see the Download from section above.

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Joined: Thu Oct 06, 2016 8:48 pm

Please be positive and constructive with your questions and comments.