Feather nRF52840 Sense

Buy

https://github.com/adafruit/Adafruit_Windows_Drivers/releases/latest
Preferences > Additional Boards Manager URL: https://www.adafruit.com/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 Error loading Python lib on older versions of MacOS, build adafruit-nrfutil from source: https://github.com/adafruit/Adafruit_nRF52_Arduino/issues/184#issuecomment-423879874
If the nRF52840 USB does not show up in Tools > Port anymore, try to update the bootloader: https://learn.adafruit.com/introducing-the-adafruit-nrf52840-feather/update-bootloader
- Double-click the nRF52840 reset button to mount /Volumes/NRF52BOOT
- Download the latest DFU firmware, e.g. feather_nrf52840_express_bootloader-0.2.9_s140_6.1.1.zip
- On MacOS, using adafruit-nrfutil-macos, type
```
$ ls /dev/cu.*
$ ./adafruit-nrfutil-macos --verbose dfu serial --package feather_nrf52840_express_bootloader-0.2.9_s140_6.1.1.zip -p /dev/cu.usbmodem -b 115200 --singlebank --touch 1200
```
- On Windows, using adafruit-nrfutil.exe, type
```
$ adafruit-nrfutil.exe --verbose dfu serial --package feather_nrf52840_express_bootloader-0.2.9_s140_6.1.1.zip --port COM -b 115200 --singlebank --touch 1200
```