The Adafruit Feather nRF52840 Express is the new Feather family member with Bluetooth Low Energy and native USB support featuring the nRF52840! Adafruit’s take on an ‘all-in-one’ Arduino-compatible + Bluetooth Low Energy with built-in USB plus battery charging. With native USB it’s even ready to join 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.
With added Arduino IDE support – you can program the nRF52840 chip directly to take full advantage of the Cortex-M4 processor and then call into the Nordic SoftDevice radio stack when you need to communicate over BLE. Since the underlying API and peripherals are the same for the ‘832 and ‘840, you can supercharge your older nRF52832 projects with the same code with a single recompile!
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 a little Python interpreter. The massive RAM and speedy Cortex M4F chip make this a good match.
It’s got tons of excellent peripherals: plenty of GPIO, analog inputs, PWM, timers, etc. Best of all, it’s got that native USB!, no need for a separate USB serial chip like CP2104 or FT232. Serial is handled as a USB CDC descriptor, and the chip can act like a keyboard, mouse, MIDI device, or even disk drive. This chip has TinyUSB support – that means you can use it with Arduino as a native USB device and act as UART (CDC), HID, Mass Storage, MIDI, and more!
Some other upgrades tossed in 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 an SWD connector.
Pre-programmed with Adafruit’s UF2 bootloader, which can use either command line UART programming with nrfutil (we use this for Arduino) or drag-n-drop mass storage for CircuitPython installation and also because mass-storage-drive bootloaders make updating firmware so easy. Ability to use Adafruit’s command-line tools with your favourite editor and toolchain. If you’re going to use an SWD programmer/debugger (for even more advanced usage), we have a standard 2×5 0.05″ connector.
Bluetooth Low Energy is the hottest new low-power, 2.4GHz spectrum wireless protocol. In particular, it’s the only wireless protocol that you can use with iOS without needing special certification and is supported by all modern smartphones. This makes it excellent for use in portable projects that will make use of an iOS or Android phone or tablet. Also is supported in Mac OS X and Windows 8 and up.
To make it easy to use for portable projects, Adafruit added a connector for a 3.7V Lithium polymer battery and built-in battery charging. Of course, you don’t need a battery because it will run fine straight from the micro USB connector. But, if you do have a battery, you can take it on the go, then plug in the USB to recharge. The Feather will automatically switch over to USB power when it’s available. We also tied the battery thru a divider to an analog pin, so you can measure and monitor the battery voltage to detect when you need a recharge.
- 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 four outputs each)
- Hardware SPI, UART, I2C and I2S on any pins
- Pin #3 red LED for general purpose blinking, NeoPixel for colourful feedback
- Power/enable pin
- 4 x mounting holes
- Reset button
- SWD connector for debugging
- Works out of the box with all of our Adafruit FeatherWings!
- Weight: 6g
- Dimensions: 51mm x 23mm x 7.2mm (without header pins)
- 1 x Adafruit Feather nRF52840 Express