Fix keyboard not working if I2C pullups not enabled.

Disable backlighting by default.

keyboards/meira/featherble/rules.mk

@@ -1,4 +1,4 @@
 BLUETOOTH_ENABLE = yes
-BACKLIGHT_ENABLE = yes
+BACKLIGHT_ENABLE = no
 F_CPU = 8000000
 

keyboards/meira/meira.c

@@ -20,6 +20,8 @@
 #include "quantum.h"
 #define BACKLIGHT_BREATHING
 
+extern void backlight_set(uint8_t level);
+
 #ifdef AUDIO_ENABLE
     float tone_startup[][2] = SONG(STARTUP_SOUND);
     float tone_goodbye[][2] = SONG(GOODBYE_SOUND);
@@ -55,7 +57,6 @@ void matrix_init_kb(void)
     wdt_enable(WDTO_500MS);
 #endif
 
-
     // put your keyboard start-up code here
     // runs once when the firmware starts up
     matrix_init_user();

keyboards/meira/promicro/rules.mk

@@ -1,2 +1,2 @@
 BLUETOOTH_ENABLE = no
-BACKLIGHT_ENABLE = yes
+BACKLIGHT_ENABLE = no

keyboards/meira/rules.mk

@@ -47,7 +47,7 @@ OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
 #   Atmel DFU loader 4096
 #   LUFA bootloader  4096
 #   USBaspLoader     2048
-OPT_DEFS += -DBOOTLOADER_SIZE=512
+OPT_DEFS += -DBOOTLOADER_SIZE=4096
 
 
 # Build Options
@@ -62,7 +62,7 @@ COMMAND_ENABLE ?= yes        # Commands for debug and configuration
 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 = yes       # Enable keyboard backlight functionality on B7 by default
+BACKLIGHT_ENABLE ?= no       # Enable keyboard backlight functionality on B7 by default
 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
@@ -70,7 +70,7 @@ AUDIO_ENABLE ?= no           # Audio output on port C6
 RGBLIGHT_ENABLE ?= no       # Enable WS2812 RGB underlight.  Do not enable this with audio at the same time.
 FAUXCLICKY_ENABLE ?= no      # Use buzzer to emulate clicky switches
 
-ISSI_ENABLE = yes			# If the I2C pullup resistors aren't install this must be disabled
+ISSI_ENABLE ?= no			# If the I2C pullup resistors aren't install this must be disabled
 #WATCHDOG_ENABLE = yes		# Resets keyboard if matrix_scan isn't run every 250ms
 
 CUSTOM_MATRIX = yes