qmk-firmware/keyboards/ploopyco/trackball/rev1
..
config.h
readme.md
rev1.h
rules.mk

See the main readme for more details.

This is just the rev 1.001-1.004 trackball

Programming QMK-DFU onto the PloopyCo Trackball (Advanced)

If you would rather have DFU on this board, you can use the QMK-DFU bootloader on the device. To do so, you want to run:

make ploopyco/trackball:default:production

Once you have that, you'll need to ISP Flash the chip with the new "production" hex file created (or the production hex), and set the fuses:

Fuse Setting
Low 0xDF
High 0xD8 or 0x98
Extended 0xCB

Original (Caterina) settings:

Fuse Setting
Low 0xFF
High 0xD8
Extended 0xFE

If you're using QMK DFU, you'll also need to add BOOTLOADER=qmk-dfu to your keymap's rules.mk file, to ensure that the reboot/reset works correctly. Otherwise, it will jump right back into the firmware, like nothing happened.

Additionally, once you've flashed the qmk-dfu bootloader onto your device, you will no longer be able to use the Arduino IDE to flash the board. You'll need to use the command line or QMK Toolbox to flash it.