Adafruit Feather nRF52

Adafruit has enriched the Feather line of boards with interesting newcomers based on the Nordic nRF52 MCUs. 

The Feather nRF52 boards feature Bluetooth (BLE) with the Nordic nRF52832 and the Nordic nRF52840.

The Nordic nRF52832 provides 512KB flash and 64KB SRAM, while the Nordic nRF52840 offers 1MB flash and 256KB SRAM.​

Hardware

Adafruit offers multiple options, up to three, to upload the executable to the boards. 
  • The first option is the standard upload procedure through serial over USB. 
  • The second option, called UF2 for USB Flashing Format, turns the board into a mass storage device. Programming is done with a simple drag-and-drop or copy of the executable onto the mass storage device. This option is only available on the Adafruit Feather nRF52840 board.
  • The third option uses an external programmer-debugger like the Segger J-Link. The Adafruit Feather nRF52840 board comes with the SWD 2x5 1.27 mm connector. It needs to be soldered on the Adafruit Feather nRF52832 board.

Software

As always, Adafruit provides the libraries for BLE and excellent documentation for each board, with the Bluefruit nRF52 Feather Learning Guide​ and the tutorial Introducing the Adafruit nRF52840 Feather.

The Bluefruit LE Connect app is available for Android and iOS smartphones and macOS, and interacts with some of the examples, like serial over BLE and colour picker.

Debugging

I managed to upload and debug with the Segger J-Link.

Both command-line J-Link and GUI-based Ozone detailed at the Segger J-Link Software page can be used to debug against the Adafruit Feather nRF52 boards.  
 
​Soldering the SWD 2x5 1.27 mm connector on the Feather nRF52832 wasn't difficult and is detailed at Segger J-Link with Adafruit Feather nRF52832. 

Pros

  • Compact form-factor
  • Excellent libraries and documentation 
  • Versatile upload procedures 

Cons

  • SWD connector to be soldered on the Feather nRF52832

Wrap-Up

  • Great value

Links