From the GitHub release page:

This is CircuitPython 8.2.1, the latest bugfix revision 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. The 8.2.0 firmware is larger than what the bootloader can handle. See these instructions for updating your bootloader.

Notable changes to 8.2.1 since 8.1.0

• Continued enhancement of synthio.
• RP2040 alarm.sleep_memory.

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 8.2.1

Most changes below are backports from main. Thanks @dhalbert for the backport pull requests.

Fixes and enhancements

• Return correct type from dict.fromkeys(). #8207, #8175. Thanks @kbsriram and @dhalbert.
• Raise NotImplementedError for os.getenv() on small boards without settings.toml support. #8206, #8169. Thanks @jepler and @dhalbert.
• Fix setting wifi.radio.hostname. #8201, #8150. Thanks @microdev1 and @dhalbert.

Port and board-specific changes

Broadcom

Espressif

• Increase maximum synthio channels to 12. #8212, #8189. Thanks @todbot.

i.MX

nRF

RP2040

• Fix RP2040 manual safe mode via reset button. #8170. Thanks @tannewt.

SAMx

SiLabs

Spresense

STM

Individual boards

• 42. Keebs Frood: Rev7 uses new flash chip. #8203, #8154. Thanks @piit79.
• Adafruit MatrixPortal S3: fix address pins. #8199, #8137. Thanks @makermelissa.
• Adafruit QT Py ESP32-S3 no PSRAM: remove frozen libraries. #8197, #8130. Thanks @dhalbert.
• Espressif ESP32-S3 Box: use PSRAM. #8197, #8129. Thanks @Neradoc.
• Espressif ESP32-S3 Box Lite: use PSRAM. #8197, #8129. Thanks @Neradoc.
• UnexpectedMaker FeatherS3: add second I2C bus. #8174. Thanks @UnexpectedMaker.

Documentation changes

• Note that wifi.radio.ipv4_address_ap is read-only. #8208, #8180. Thanks @anecdata and @dhalbert.
• Document various networking restrictions. #8205, #8165. Thanks @anecdata and @dhalbert.
• Automate documentation of optional types and functions. #8185. Thanks @jepler.
• Fix zlib.decompress() name. #8195, #8125. Thanks @jimmo.

Build and infrastructure changes

Translation additions and improvements

New boards since 8.2.0

• Adafruit Metro M7 1011 SD. #8196, #8127. Thanks @dhalbert.
• Adafruit Metro RP2040. #8181. #8194, #8035. Thanks @dhalbert and @jepler.
• Adafruit QT Py ESP32-S3 4MB Flash 2MB PSRAM. #8198, #8130. Thanks @dhalbert.
• Datanoise PicoADK. #8204, #8166, #8156. Thanks @DatanoiseTV and @dhalbert.
• Makerdiary nRF52840 Connect Kit. #8200, #8142. Thanks @makerdiary.
• splitkb.com Liatris. #8202, #8152. Thanks @splitkb.

Known issues

• ESP32-S3 has significant issues with I2C devices that sleep or use clock stretching. Retry operations on these devices as necessary, or use ESP32-S2 boards.
• Espressif boards have ESP-IDF storage leaks and occasionally crash after extended WiFi use.
• See https://github.com/adafruit/circuitpython/issues for other issues, including issues still to be addressed for:
  • 8.2.x
  • 9.0.0
  • long term

Thanks

Thank you to all who used, tested, and contributed since 8.2.0, including the contributors above, and many others on GitHub and Discord. Join us on the Discord chat to collaborate.