qmk_firmware_custom/keyboards/preonic/rev3/rules.mk

# project specific files
SRC = matrix.c

# Cortex version
MCU  = STM32F303

# 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 = yes      # Virtual DIP switch configuration(+1000)
## (Note that for BOOTMAGIC on Teensy LC you have to use a custom .ld script.)
MOUSEKEY_ENABLE = yes      # Mouse keys(+4700)
EXTRAKEY_ENABLE = yes       # Audio control and System control(+450)
CONSOLE_ENABLE = yes         # Console for debug(+400)
COMMAND_ENABLE = yes       # 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 = no       # 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 = no        # Enable WS2812 RGB underlight.
API_SYSEX_ENABLE = no

# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
SLEEP_LED_ENABLE = no    # Breathing sleep LED during USB suspend
#SLEEP_LED_ENABLE = yes

CUSTOM_MATRIX = yes # Custom matrix file
# SERIAL_LINK_ENABLE = yes
ENCODER_ENABLE = yes

LAYOUTS = ortho_5x12