qmk_firmware_custom/keyboards/gingham/rules.mk

SRC = matrix.c \
      i2c_master.c

# MCU name
MCU = atmega328p
PROTOCOL = VUSB

# Processor frequency.
#     This will define a symbol, F_CPU, in all source code files equal to the
#     processor frequency in Hz. You can then use this symbol in your source code to
#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
#     automatically to create a 32-bit value in your source code.
#
#     This will be an integer division of F_USB below, as it is sourced by
#     F_USB after it has run through any CPU prescalers. Note that this value
#     does not *change* the processor frequency - it should merely be updated to
#     reflect the processor speed set externally so that the code can use accurate
#     software delays.
F_CPU = 16000000

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

# Input clock frequency.
#     This will define a symbol, F_USB, in all source code files equal to the
#     input clock frequency (before any prescaling is performed) in Hz. This value may
#     differ from F_CPU if prescaling is used on the latter, and is required as the
#     raw input clock is fed directly to the PLL sections of the AVR for high speed
#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
#     at the end, this will be done automatically to create a 32-bit value in your
#     source code.
#
#     If no clock division is performed on the input clock inside the AVR (via the
#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
F_USB = $(F_CPU)

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

# Bootloader selection
#   Teensy       halfkay
#   Pro Micro    caterina
#   Atmel DFU    atmel-dfu
#   LUFA DFU     lufa-dfu
#   QMK DFU      qmk-dfu
#   atmega32a    bootloadHID
#
# This uses usbaspbootloader
# BOOTLOADER = atmel-dfu

# If you don't know the bootloader type, then you can specify the
# Boot Section Size in *bytes* by uncommenting out the OPT_DEFS line
#   Teensy halfKay      512
#   Teensy++ halfKay    1024
#   Atmel DFU loader    4096
#   LUFA bootloader     4096
#   USBaspLoader        2048
# OPT_DEFS += -DBOOTLOADER_SIZE=4096
OPT_DEFS += -DBOOTLOADER_SIZE=2048

# Flash program via avrdude, but default command is not suitable.
# You can use plaid:default:program
PROGRAM_CMD = avrdude -c usbasp -p m328p -U flash:w:$(BUILD_DIR)/$(TARGET).hex

# disable debug code
OPT_DEFS = -DDEBUG_LEVEL=0

# Build Options
#   change yes to no to disable
#
BOOTMAGIC_ENABLE = lite      # Virtual DIP switch configuration(+1000)
MOUSEKEY_ENABLE = yes       # 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
# 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 on B7 by default
RGBLIGHT_ENABLE = no        # Enable keyboard RGB underglow
MIDI_ENABLE = no            # MIDI support (+2400 to 4200, depending on config)
UNICODE_ENABLE = no         # Unicode
BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
AUDIO_ENABLE = no           # Audio output on port C6
FAUXCLICKY_ENABLE = no      # Use buzzer to emulate clicky switches
HD44780_ENABLE = no 		# Enable support for HD44780 based LCDs (+400)

# unsupported features for now
NO_UART = yes
NO_SUSPEND_POWER_DOWN = yes
CUSTOM_MATRIX           = yes