Feather nRF52840 Sense

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Preferences > Additional Boards Manager URL: https://adafruit.github.io/arduino-board-index/package_adafruit_index.json
Tools > Board > Boards Manager... > Adafruit nRF52

Linux only:

$ sudo apt-get install python3
$ pip3 install --user adafruit-nrfutil
$ adafruit-nrfutil version
adafruit-nrfutil version 0.5.3.post12

If the modem manager interferes with adafruit-nrfutil, try

$ sudo bash -c "systemctl stop ModemManager && systemctl disable ModemManager"

If you get an Undefined reference to Serial error, add #include "Adafruit_TinyUSB.h";, see https://github.com/tamberg/fhnw-iot/issues/22
If you get Error loading Python lib, update adafruit-nrfutil, see https://github.com/tamberg/fhnw-iot/issues/21
If the nRF52840 USB does not show up in Tools > Port anymore, double-click the reset button.
If that does not help, try to update the bootloader as described in https://learn.adafruit.com/introducing-the-adafruit-nrf52840-feather/update-bootloader
If you get Error compiling for board Adafruit Feather Bluefruit Sense:
- If the log contains something like adafruit-nrfutil.exe file does not exist
- Add an exclusion for the adafruit-nrfutil.exe file to your anti virus scanner, as shown here.
If, on Linux, you get an upload failed message with error /dev/ttyACM0 permission denied:
- Make sure your user has enough permissions to access /dev/ttyACM0
- Check permissions of /dev/ttyACM0: ls -alh /dev/ttyACM0
- Add your user to the corresponding group (e.g. Arch Linux uucp) or change permissions of /dev/ttyACM0