qmk_firmware_custom/keyboards/lfkeyboards/lfk87/rules.mk

# Set the LFK87 hardware version.
#
# A - Green PCB. at90usb1286 Only 3 exist
# B - We don't talk about RevB
# C-D - Black PCB. at90usb646 First public release
#
LFK_REV = C

ifeq ($(LFK_REV), A)
	MCU = at90usb1286
	OPT_DEFS += -DBOOTLOADER_SIZE=8192
else
	MCU = at90usb646
	OPT_DEFS += -DBOOTLOADER_SIZE=4096
endif
OPT_DEFS += -DLFK_TKL_REV_$(LFK_REV)

# Extra source files for IS3731 lighting
SRC = TWIlib.c issi.c lighting.c

# Processor frequency.
F_CPU = 16000000

# Target architecture (see library "Board Types" documentation).
ARCH = AVR8

# Input clock frequency.
F_USB = $(F_CPU)

# Interrupt driven control endpoint task(+60)
OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT

LAYOUTS = tkl_ansi tkl_iso

# Build Options
#   change to "no" to disable the options, or define them in the Makefile in
#   the appropriate keymap folder that will get included automatically
#

BOOTMAGIC_ENABLE = no           # Virtual DIP switch configuration(+1000)
MOUSEKEY_ENABLE = no            # Mouse keys(+4700)
EXTRAKEY_ENABLE = yes           # Audio control and System control(+450)
CONSOLE_ENABLE = no             # Console for debug(+400)
COMMAND_ENABLE = no             # Commands for debug and configuration
NKRO_ENABLE = yes               # Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
BACKLIGHT_ENABLE = yes           # Enable keyboard backlight functionality
MIDI_ENABLE = no                # MIDI controls
AUDIO_ENABLE = yes              # Audio output on port C6
UNICODE_ENABLE = no             # Unicode
BLUETOOTH_ENABLE = no           # Enable Bluetooth with the Adafruit EZ-Key HID
RGBLIGHT_ENABLE = yes           # Enable RGB underlight
RGBLIGHT_CUSTOM_DRIVER = yes    # RGB code is implemented in lefkeyboards, not WS2812
SLEEP_LED_ENABLE = yes          # Breathing sleep LED during USB suspend
TAP_DANCE_ENABLE = no

ISSI_ENABLE = yes			# If the I2C pullup resistors aren't install this must be disabled
WATCHDOG_ENABLE = no		# Resets keyboard if matrix_scan isn't run every 250ms



ifeq ($(strip $(ISSI_ENABLE)), yes)
    OPT_DEFS += -DISSI_ENABLE
endif

ifeq ($(strip $(WATCHDOG_ENABLE)), yes)
    OPT_DEFS += -DWATCHDOG_ENABLE
endif