CircuitPython 8.1.0 Release Candidate 0 Released! @circuitpython

CircuitPython 8.1.0 Release Candidate 0 Released! @circuitpython

Source Node: 2096652

From the GitHub release page:

This is CircuitPython 8.1.0-rc.0, a release candidate for 8.1.0. We believe it is stable, and are making a release candidate for further testing before final release.

Notable changes to 8.1.0 since 8.0.0

  • Silicon Labs (SiLabs) MG24 microcontroller family port (silabs), contributed by Silicon Labs.
  • Add animated GIF support, including palette support: gifio.OnDiskGif.
  • Add, for programmatic handling of safe mode.
  • Add ESP-NOW support on Espressif.
  • synthio improvements and new features; API is still experimental and may change after 8.1.0.
  • Add picodvi on RP2040: DVI/HDMI framebuffer and displayio support.
  • CPU frequency is settable on RP2040.
  • Add 7-color e-ink display support.
  • Add bitmaptools.drawpolygon().
  • Allow setting pystack size in settings.toml.
  • Allow static IPv4 addresses for access points.
  • Add dither support to Palette.
  • Support array.extend(iterable).

Download from

Firmware downloads are available from the downloads page on The site makes it easy to select the correct file and language for your board.


To install follow the instructions in the 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).


Documentation is available in

Port status

CircuitPython has a number of “ports” that are the core implementations for different microcontroller families. Stability varies on a per-port basis. As of this release, these ports are consider stable (but see Known Issues below):

  • atmel-samd: Microchip SAMD21, SAMx5x
  • cxd56: Sony Spresense
  • espressif: Espressif ESP32, ESP32-S2, ESP32-S3, ESP32-C3
  • nrf: Nordic nRF52840, nRF52833
  • raspberrypi: Raspberry Pi RP2040
  • stm: ST STM32F4 chip family

These ports are considered alpha and will have bugs and missing functionality:

  • broadcom: Raspberry Pi boards such as RPi 4, RPi Zero 2W
  • litex: fomu
  • mimxrt10xx: NXP i.MX RT10xxx
  • silabs: Silicon Labs MG24 family
  • stm: ST non-STM32F4 chip families

Changes since 8.1.0-beta.2

Fixes and enhancements

  • Fix display object management. #2204. Thanks @furbrain.
  • Allow no chip select pin in native adafruit_bus_device.spi_device. #7970. Thanks @dhalbert.
  • Continued synthio improvements and fixes. #7969, #7959, #7933, #7862. Thanks @jepler.
  • Prevent WiFi workflow background activity if WiFi not connected. #7960. Thanks @thess.
  • Improve vectorio.Polygon argument validation. #7947. Thanks @FoamyGuy.
  • Support little-endian e-paper displays; fix display memory management. #7891. Thanks @tannewt.

Port and board-specific changes



  • Improve serial input in ESP32-C3 and similar chips. #7973. Thanks @tannewt.
  • Improve debug builds. #7972. Thanks @tannewt.
  • Add missing ESP32-S3 microntroller.Pin pins. #7967. Thanks @bojanpotocnik.
  • Report actual busio.SPI().frequency. #7963. Thanks @dhalbert.
  • Allow static IPv4 for access point. #7946. Thanks @anecdata.
  • Fix crash when sending rapid pings. #7938. Thanks @jepler.
  • Add documentation that supervisor.next_stack_limit() has no effect. #7914. Thanks @anecdata.


  • Fix pin pad handling. #7964. Thanks @tannewt.
  • Fix regressions, startup and MIDI problems. #7953. Thanks @jepler.
  • Update TinyUSB, fix unimplemented Processor routines, script for peripheral generation. #7921. Thanks @tannewt.


  • Implement memorymap. #7942. Thanks @furbrain.


  • Wait for to complete. #7982. Thanks @bill88t.
  • Allow static IPv4 for access point. #7976. Thanks @anecdata.
  • picodvi now takes framebuffer resolution instead of output resolution. #7922. Thanks @tannewt.
  • Allow setting cpu.frequency. #7430. Thanks @Lanzaa.



  • Initialize RTC to prevent time crashes. #7939. Thanks @RetiredWizard.



  • Preserve monotonicity of time routines after RTC date/time change. #7965. Thanks @dhalbert.

Individual boards

  • Adafruit Feather RP2040: add board.BUTTON/board.BOOT for GPIO4, for rev D and later boards. #7988. Thanks @Neradoc.
  • Adafruit Feather RP2040 ThinkInk: rename board, add board.BUTTON. #7927. Thanks @BlitzCityDIY.
  • Sprig Hack Club: add board.DISPLAY. #7958. Thanks @ajs256.

Documentation changes

  • Document settings.toml CIRCUITPY_PYSTACK_SIZE. #7951. Thanks @Neradoc.
  • Add __contains__() stub to displayio.Group. #7949. Thanks @FoamyGuy.

Build and infrastructure changes

  • Update how Python stubs are built. #7957, #7934. Thanks @tekktrik.
  • Update shallow clone tag. #7909. Thanks @mjsir911.

Translation additions and improvements

  • Thanks for translations:
    • @ChenxiXiao (Chinese – Pinyin)
    • @luisan00 (Spanish)
    • @Yutaro Urata (Japanese)

New boards since 8.1.0-beta.2

  • Adafruit Feather RP2040 Prop-Maker. #7877. Thanks @dhalbert.
  • Lilygo T-Display. #6037. Thanks @erongd.
  • NXP IMXRT1015-EVK. #7921. Thanks @tannewt.
  • NXP iMXRT RT 1040EVK. #7921. Thanks @tannewt.
  • NXP iMXRT RT 1050EVKB. #7921. Thanks @tannewt.
  • Pimoroni Inky Frame 5.7. #7962. Thanks @tannewt.
  • Pimoroni Badger 2040 W. #7916. Thanks @bablokb.
  • Pimoroni Pico DV Demo Base for Pico. #7915. Thanks @RetiredWizard.
  • Pimoroni Plasma 2040 W. #7920. Thanks @bablokb.

Known issues

  • ESP32-S3 has issues with I2C devices that sleep (LC709203F), use clock stretching, or violate the I2C protocol (e.g., BNO055). Retry operations on these devices as necessary, or use ESP32-S2 boards.
  • ESP32-S2 used as an HTTP server may crash after several hours. This is a regression from 7.x.x.
  • See for other issues, including issues still to be addressed for:


Thank you to all who used, tested, and contributed since 8.1.0-beta.2, including the contributors above, and many others on GitHub and Discord. Join us on the Discord chat to collaborate.

Time Stamp:

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