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UF2 Bootloader

All SliceMK products come preinstalled with a UF2 bootloader, which makes it extremely easy update the device firmware.

The bootloader works by presenting as a virtual USB mass storage device. Flashing the firmware is as simple as dragging and dropping a UF2 file into the virtual drive.

Flashing Information​

  • The name of the UF2 file is not important; only the content matters. To flash a UF2 file, simply copy it to the virtual drive. Additionally, it is not necessary to touch any of the drive's existing files.
  • After copying the UF2 file, you will likely encounter an ejection or file copy error depending on your operating system. This is the expected behavior and indicates that flashing was successful.
  • If you subsequently return to bootloader mode, the UF2 file you copied previously will no longer be there. This is the expected behavior; the drive is a completely virtual and merely a transport mechanism.
  • If the virtual drive does not disappear after copying the firmware file, most likely it is incompatible with the device. Please double check that you built or downloaded the firmware file for the correct device. If you're not sure, feel free to contact support for additional help.

Bootloader Mode​

In order to initiate the flashing process, the device must be plugged in and placed in bootloader mode. Please refer to the Buttons and LEDs for details on how to do that.

Once in bootloader mode, the virtual drive for flashing will appear.

  • The virtual drive for SliceMK keyboard halves is named SliceMK.
  • The virtual drive for SliceMK dongles is named MDBT50QBOOT or NRF52BOOT depending on the dongle model.
tip

Once you have your keyboard firmware up and running, you can add a &bootloader key to your ZMK keymap. This allows you to enter bootloader mode more conveniently by pressing a key on your keyboard.