qmk_firmware/keyboards/ploopyco/trackball/rules.mk

# MCU name
MCU = atmega32u4

# Processor frequency
F_CPU = 8000000

# Build Options
#   change yes to no to disable
#
BOOTMAGIC_ENABLE = lite     # Virtual DIP switch configuration
EXTRAKEY_ENABLE = yes       # Audio control and System control
CONSOLE_ENABLE = no         # Console for debug
COMMAND_ENABLE = no         # Commands for debug and configuration
# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
SLEEP_LED_ENABLE = no       # Breathing sleep LED during USB suspend
# if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
NKRO_ENABLE = no            # USB Nkey Rollover
BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
RGBLIGHT_ENABLE = no        # Enable keyboard RGB underglow
UNICODE_ENABLE = no         # Unicode
BLUETOOTH_ENABLE = no       # Enable Bluetooth
AUDIO_ENABLE = no           # Audio output
POINTING_DEVICE_ENABLE = yes
MOUSEKEY_ENABLE = yes       # Mouse keys

QUANTUM_LIB_SRC += analog.c spi_master.c
SRC += pmw3360.c opt_encoder.c

DEFAULT_FOLDER = ploopyco/trackball/rev1_005