CircuitPython 9.0.4

This is CircuitPython 9.0.4, the latest bugfix release of CircuitPython, and is a new stable release.

WARNING for nRF52 boards only: If your board has an nRF52 UF2 bootloader whose version is before 0.6.1, you will not be able to load CircuitPython 8.2.0 and later, due to increased size of the firmware. See these instructions for updating your bootloader.

For notable changes to 9.0.0 since 8.x.x, see the 9.0.0 release notes.

Download from circuitpython.org

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

Installation

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

Documentation is available in readthedocs.io.

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 9.0.3

Fixes and enhancements

• External flash cache allocation crashed into safe mode when heap was too small. #9169. Thanks @dhalbert.

Port and board-specific changes

Broadcom

Espressif

i.MX

nRF

• Move state word that survives reset to avoid its being overwritten by bootloader. #9168, #9160. Thanks @tannewt.
• Fix regression from 9.0.3 treating small internal-only negative ADC values as large positive values. #9161. Thanks @dhalbert.
• Allow reuse of AnalogIn pins as other types of pins. #9161. Thanks @dhalbert.

RP2040

SAMx

SiLabs

Spresense

STM

Individual boards

Documentation changes

Build and infrastructure changes

Translation additions and improvements

New boards since 9.0.3

Known issues

• See https://github.com/adafruit/circuitpython/issues for other issues, including issues still to be addressed for:
  • 9.0.x
  • 9.1.0
  • 9.x.x
  • long term

Thanks

Thank you to all who used, tested, and contributed since 9.0.3, including the contributors above, and many others on GitHub and Discord. Join us on the Discord chat to collaborate.