Feather nRF52840 Express
by Adafruit
The Adafruit Feather nRF52840 Express is the new Feather family member with Bluetooth Low Energy and native USB support featuring the nRF52840! It is Adafruit’s take on an ‘all-in-one’ Bluetooth Low Energy device with built in USB plus battery charging. With native USB it’s part of the CircuitPython party.
This chip has twice the flash, and four times the SRAM of its earlier sibling, the nRF52832 - 1 MB of FLASH and 256KB of SRAM. Compared to the nRF51, this board has 4-8 times more of everything.
This is Adafruit’s first BLE-friendly CircuitPython board! CircuitPython works best with disk drive access, and this is the only BLE-plus-USB-native chip that has the memory to handle running the Python interpreter. The massive RAM and speedy Cortex M4F chip makes this a good match.
It’s got tons of peripherals: plenty of GPIO, analog inputs, PWM, timers, etc. Best of all, it’s got that native USB! Finally, no need for a separate USB serial chip like CP2104 or FT232.
Some other upgrades are an extra ‘USER’ switch that could be used to trigger OTA updates (or whatever you choose), a NeoPixel LED for status updates, 2 MB of QSPI Flash for storing CircuitPython files, and a SWD connector.
Comes pre-programed the chip with a UF2 bootloader, which can use either command line UART programming with nrfutil or drag-n-drop mass storage, for CircuitPython installation and also because mass-storage-drive bootloaders make updating firmware so easy. Want to program the chip directly? You can use command line tools with your favorite editor and toolchain. If you want to use an SWD programmer/debugger (for even more advanced usage), use a standard 2x5 0.05” connector.
Features:
- ARM Cortex M4F (with HW floating point acceleration) running at 64MHz
- 1MB flash and 256KB SRAM
- Native Open Source USB stack - pre-programmed with UF2 bootloader
- Bluetooth Low Energy compatible 2.4GHz radio (Details available in the nRF52840 product specification)
- FCC / IC / TELEC certified module
- Up to +8dBm output power
- 1.7v to 3.3v operation with internal linear and DC/DC voltage regulators
- 21 GPIO, 6 x 12-bit ADC pins, up to 12 PWM outputs (3 PWM modules with 4 outputs each)
- Pin #3 red LED for general purpose blinking, NeoPixel for colorful feedback
- Power/enable pin
- Measures 2.0” x 0.9” x 0.28” (51mm x 23mm x 7.2mm) without headers soldered in
- Light as a (large?) feather - 6 grams
- 4 mounting holes
- Reset button
- SWD connector for debugging
Tutorial
Purchase
Contribute
Have some info to add for this board? Edit the source for this page here.
CircuitPython 9.2.1
This is the latest stable release of CircuitPython that will work with the Feather nRF52840 Express.
Use this release if you are new to CircuitPython.
On nRF boards, CircuitPython 8.2.0 and later require UF2 bootloader version 0.6.1 or later. Older bootloaders cannot load the firmware. See Update UF2 Bootloader below.
Built-in modules available: _asyncio, _bleio, _pixelmap, adafruit_bus_device, adafruit_pixelbuf, aesio, alarm, analogio, array, atexit, audiobusio, audiocore, audiomixer, audiomp3, audiopwmio, binascii, bitbangio, bitmapfilter, bitmaptools, board, builtins, builtins.pow3, busdisplay, busio, busio.SPI, busio.UART, codeop, collections, countio, digitalio, displayio, epaperdisplay, errno, fontio, fourwire, framebufferio, getpass, gifio, i2cdisplaybus, io, jpegio, json, keypad, keypad.KeyMatrix, keypad.Keys, keypad.ShiftRegisterKeys, keypad_demux, keypad_demux.DemuxKeyMatrix, locale, math, memorymap, microcontroller, msgpack, neopixel_write, nvm, onewireio, os, os.getenv, paralleldisplaybus, pulseio, pwmio, rainbowio, random, re, rgbmatrix, rotaryio, rtc, sdcardio, select, sharpdisplay, storage, struct, supervisor, synthio, sys, terminalio, time, touchio, traceback, ulab, usb_cdc, usb_hid, usb_midi, vectorio, warnings, watchdog, zlib
Features: Feather-Compatible, Battery Charging, Bluetooth/BTLE, Breadboard-Friendly
Absolute Newest
Every time we commit new code to CircuitPython we automatically build binaries for each board and language. The binaries are stored on Amazon S3, organized by board, and then by language. These releases are even newer than the development release listed above. Try them if you want the absolute latest and are feeling daring or want to see if a problem has been fixed.
Previous Versions of CircuitPython
All previous releases of CircuitPython are available for download from Amazon S3 through the button below. For very old releases, look in the OLD/ folder for each board. Release notes for each release are available at GitHub button below.
Older releases are useful for testing if you something appears to be broken in a newer release but used to work, or if you have older code that depends on features only available in an older release. Otherwise we recommend using the latest stable release.
Update UF2 Bootloader
Latest version: 0.9.2
The bootloader allows you to load CircuitPython, MakeCode, and Arduino programs. The bootloader is not CircuitPython. You can check the current version of your bootloader by looking in the INFO_UF2.TXT file when the BOOT drive is visible (FEATHERBOOT, CPLAYBOOT, etc.).
It is not necessary to update your bootloader if it is working fine. Read the release notes on GitHub to see what has been changed. In general, we recommend you not update the bootloader unless you know there is a problem with it or a support person has asked you to try updating it.
On nRF boards, CircuitPython 8.2.0 and later require UF2 bootloader version 0.6.1 or later. Older bootloaders cannot load the firmware. To check the version of your board's bootloader, look at INFO_UF2.TXT when the BOOT drive is present. To update the bootloader, refer to the "Update Bootloader" page in the guide for your board, or start with this page.
After you update, check INFO_UF2.TXT to verify that the bootloader version has been updated. Then you will need to reload CircuitPython.