I have been experimenting with custom keyboard layers and keyboards. An annoying difficulty I came across was flashing hex files to my microcontrollers at least on linux OSes. qmk toolbox is a great gui application that makes flashing hex and bin files to microcontrollers a breeze. Unfortunately qmk_toolbox is only available for Windows and MacOS. The solution I am about to outline should work on most linux distros, I use NixOs btw.

  • Search for the dfu-programmer for your distro and install it. On NixOs it’s easy as: 
    nix-env -iA nixos.dfu-programmer
  • on ubuntu 
    sudo apt-get install dfu-programmer
  • on arch linux 
    sudo pacman -S dfu-programmer
  • Create or get the hex file you want to compile 
    cd ~/.qmk_firmware
qmk compile -kb handwired/dactyl_manuform/5x6 -km colemak-dh
ls ./handwired_dactyl_manuform_5x6_colemak-dh
  • Make sure your microcontroller is connected via usb and verify with lsusb 
    lsusb

  • Press the hardware reset button on your microcontroller to put the system into bootloader mode

  • Check to see if the device is recognized by dfu-programmer 
    # dfu-programmer name_of_board command_to_execute_on_board
 dfu-programmer atmega32u4 get

    this should output the bootloader version number.

  • Erase the current firmware to prep the board for the new firmware you want to flash 
    dfu-programmer atmega32u4 erase --force
  • Flash the file to the microcontroller board 
    dfu-programmer atmega32u4 flash ./handwired_dactyl_manuform_5x6_colemak-dh.hex
  • Reset the board ( I honestly do not know why you have type this command but you cannot start using your keeb unless you type this command or disconnect and reconnect your microcontroller. 
    dfu-programmer atmega32u4 reset

resources

man dfu-programmer

See https://dfu-programmer.github.io/
See SUPPORTED MICROCONTROLLERS section of the dfu-programmer man page for the supported microcontrollers.