+You can currently send 4 hex digits with your OS-specific modifier key (RALT for OSX with the "Unicode Hex Input" layout, see [this article](http://www.poynton.com/notes/misc/mac-unicode-hex-input.html) to learn more) - this is currently limited to supporting one OS at a time, and requires a recompile for switching. 8 digit hex codes are being worked on. The keycode function is `UC(n)`, where *n* is a 4 digit hexidecimal. Enable from the Makefile.
+
+## Backlight Breathing
+
+In order to enable backlight breathing, the following line must be added to your config.h file.
+
+ #define BACKLIGHT_BREATHING
+
+The following function calls are used to control the breathing effect.
+
+* ```breathing_enable()``` - Enable the free-running breathing effect.
+* ```breathing_disable()``` - Disable the free-running breathing effect immediately.
+* ```breathing_self_disable()``` - Disable the free-running breathing effect after the current effect ends.
+* ```breathing_toggle()``` - Toggle the free-running breathing effect.
+* ```breathing_defaults()``` - Reset the speed and brightness settings of the breathing effect.
+
+The following function calls are used to control the maximum brightness of the breathing effect.
+
+* ```breathing_intensity_set(value)``` - Set the brightness of the breathing effect when it is at its max value.
+* ```breathing_intensity_default()``` - Reset the brightness of the breathing effect to the default value based on the current backlight intensity.
+
+The following function calls are used to control the cycling speed of the breathing effect.
+
+* ```breathing_speed_set(value)``` - Set the speed of the breathing effect - how fast it cycles.
+* ```breathing_speed_inc(value)``` - Increase the speed of the breathing effect by a fixed value.
+* ```breathing_speed_dec(value)``` - Decrease the speed of the breathing effect by a fixed value.
+* ```breathing_speed_default()``` - Reset the speed of the breathing effect to the default value.
+
+The following example shows how to enable the backlight breathing effect when the FUNCTION layer macro button is pressed:
+
+ case MACRO_FUNCTION:
+ if (record->event.pressed)
+ {
+ breathing_speed_set(3);
+ breathing_enable();
+ layer_on(LAYER_FUNCTION);
+ }
+ else
+ {
+ breathing_speed_set(1);
+ breathing_self_disable();
+ layer_off(LAYER_FUNCTION);
+ }
+ break;
+
+The following example shows how to pulse the backlight on-off-on when the RAISED layer macro button is pressed:
+
+ case MACRO_RAISED:
+ if (record->event.pressed)
+ {
+ layer_on(LAYER_RAISED);
+ breathing_speed_set(2);
+ breathing_pulse();
+ update_tri_layer(LAYER_LOWER, LAYER_RAISED, LAYER_ADJUST);
+ }
+ else
+ {
+ layer_off(LAYER_RAISED);
+ update_tri_layer(LAYER_LOWER, LAYER_RAISED, LAYER_ADJUST);
+ }
+ break;