From the GitHub release page:

This is CircuitPython 7.3.0-rc.2, the third release candidate for CircuitPython 7.3.0. It is considered stable, and is available as a release candidate for testing before the final release of 7.3.0.

Notable changes to 7.3.0 since 7.2.5

• Experimental mDNS support.
• USB to to Serial/JTAG support for REPL on appropriate boards.
• Initial experimental USB host support.
• Merge MicroPython 1.18 changes.
• Preliminary zlib module support. gzip module will be added later.
• RP2040 PIO: Background write to a PIO state machine. Looping is possible.
• RP2040 PIO: wrap and wrap_target support.
• keypad: scan keystates immediately on creation.
• Improve NeoPixel timings on many ports, to handle a wider range of devices.
• Add floppyio, used in conjunction with a library.
• Allow TileGrid bitmap to be changed.
• Module support matrix includes frozen modules for each board.
• f-strings available in all builds.

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:

• atmel-samd: Microchip SAMD21, SAMx5x
• cxd56: Sony Spresense
• espressif: Espressif ESP32-S2
• 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
• espressif: ESP32-S3, ESP32-C3
• litex: fomu
• mimxrt10xx: NXP i.MX RT10xxx
• stm: ST non-STM32F4 chip families

Changes since 7.3.0-rc.1

Fixes and enhancements

• Turn on f-strings for all builds. #6415. Thanks @dhalbert.

Port and board-specific changes

Broadcom

Espressif

i.MX

nRF

RP2040

SAMx

STM

Individual boards

Documentation changes

Build and infrastructure changes

Translation additions and improvements

New boards since 7.3.0-rc.1

Known issues

• See https://github.com/adafruit/circuitpython/issues for other issues, including issues still to be addressed for:

Thanks

Thank you to all who used, tested, and contributed since 7.3.0-rc.1, including the contributors above, and many others on GitHub and Discord. Join us on the Discord chat to collaborate.