CircuitPython 4.0.0 Beta 7 released!

From the GitHub release page:

We are nearing the end of the betas of 4.0.0, and hope this will be the last beta. There are still a few issues to fix before stable. We think the API’s are now stable. Please use the latest 3.x stable release (available from the new website!) when first starting with CircuitPython. It is stable.

When you find a bug please check the current known issues and file an issue if something isn’t already known.

circuitpython.org

Downloads are now available from circuitpython.org! This site makes it much easier to select the correct file and language for your board. The downloads page is here.

4.0.0

4.0.0 is the latest major revision of CircuitPython. It features:

• extensive new support for pixel-based displays (displayio)
• a port to the Nordic nRF52840 microcontroller, including support as a BLE beacon or peripheral (bleio)
• USB MIDI support
• messages translated into multiple languages

Installation

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, Updates, and Fixes since Beta 6

• Fixed missing rotaryio. Thanks @dhalbert
• nrf52840: Support rtc. Thanks @nickzoic and @dhalbert
• Fixed displayio.Group insert bug. Thanks @caternuson
• Fixed USB issues after disconnect. Thanks @hathach and @dhalbert
• Add data as command support to displayio. Thanks @makermelissa
• Add support for CS toggle every display command. Thanks @makermelissa
• Add input validation in displayio which fixes some crashes. Thanks @tannewt
• Add access do display bus on Display. Thanks @deshipu
• Fix crash when releasing displays multiple times. Thanks @tannewt
• Fix recursive background calls. Thanks @dhalbert
• Add support for board aliases (same bin, separate download). Thanks @tannewt

New and Updated Translations

• Added Chinese (Pinyin) as a new translation. Many thanks to @hexthat

New Boards

• Electronic Cats Bast Pro Mini M0. Thanks @sabas1080
• Adafruit Metro M4 Airlift Lite. Thanks @ladyada
• Kicksat sprite. Thanks @maholli
• CircuitPlayground Express 4H Edition (alias) Thanks @tannewt
• CircuitPlayground Express Digikey PyCon 2019 (alias) Thanks @tannewt
• Gemma M0 PyCon 2018 (alias) Thanks @tannewt
• PewPew 10.3 (alias) Thanks @tannewt

Breaking Changes from 3.x!

• ure, ujson, and uerrno renamed to re, json, and errno to reflect that they are subsets of the CPython library modules. Thanks to @dhalbert.
• busio.UART breaking changes to match PySerial. Thanks to @dhalbert.
  • busio.UART constructor timeout parameter is now in seconds instead of milliseconds.
  • UART.readinto(buf) now does not allow an optional length parameter UART.readinto(buf, len).
  • UART.write(…) no longer allows strings to be written. The bytes written must be bytes or bytearray or an array.array.
• framebuf has been removed. displayio is its replacement, and will be enhanced after 4.0 to include framebuf‘s functionality. Thanks to @tannewt.
• Improve struct compatibility with CPython by enforcing stricter types. This may break your code! Thanks to @dhalbert.

Thanks

Thank you to all who used, tested, contributed, helped out, and participated on GitHub and/or Discord:
@adafruit, @anecdata, @arofarn, @arturo182, @ATMakersBill, @barbudor, @brennen, @brentru, @bwshockley, @C47D, @CarlFK, @carlosperate, @caternuson, @CedarGroveStudios, @chalei, @charlesbunaford, @cpforbes, @CraigF, @dastels, @deshipu, @dhalbert, @dsiee, @edspark, @eighthree, @emteeoh, @furlaneto, @gcvasconcelos, @glennrub, @gpshead, @hathach, @iraytrace, @Jahor, @jasonp, @jepler, @Jay Doscher, @jerryneedell, @jimblom, @JohnPark, @JoshuaLowe1002, @juanita, @KacperLA, @kattni, @kevinjwalters, @klardotsh, @Klowner, @ladyada, @larsks, @madbodger, @maholli, @Makdaam, @MakerMelissa, @MattyT, @mchobby, @microbuilder, @MikeBarela, @Mr. Certainly, @mrmcwethy, @nickzoic, @notro, @oldcrow, @penguindustin, @PhredFL, @platipo, @Rathmore, @Retoc, @rhooper, @sabas1080, @sajattack, @sajattack, @saspa, @schmarty, @Senuros, @ShawnHymel, @siddacious, @sommersoft, @SouthernDragon, @TangoJuliett, @tannewt, @Tasm-Devil, @TG-Techie, @uhrheber, @urish, @vgoodwinv, @xpecex, @yeyeto2788, @jreese, @hexthat and surely more we have missed. Join us on the Discord chat to collaborate.

Documentation

Documentation is available in readthedocs.io.

Here are all the changes since 4.0.0-beta.6.
Here are all the changes since 3.1.2.

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

Troubleshooting

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.