### RGB Matrix support for split common ([#11055](https://github.com/qmk/qmk_firmware/pull/11055)) :id=rgb-matrix-split-common
Split boards can now use RGB Matrix without defining a custom matrix.
### Teensy 3.6 support ([#12258](https://github.com/qmk/qmk_firmware/pull/12258)) :id=teensy-3-6-support
Added support for MK66F18 (Teensy 3.6) microcontroller.
### New command: qmk console ([#12828](https://github.com/qmk/qmk_firmware/pull/12828)) :id=new-command-qmk-console
A new `qmk console` command has been added for attaching to your keyboard's console. It operates similiarly to QMK Toolbox by allowing you to connect to one or more keyboard consoles to display debugging messages.
We've updated the `qmk config` command to show only the configuration items you have actually set. You can now display (almost) all of the available configuration options, along with their default values, using `qmk config -a`.
The [Function96 V2](https://github.com/qmk/qmk_firmware/tree/0.13.0/keyboards/function96/v2) has also been added as part of these changes.
The codebase for the [Durgod K320](https://github.com/qmk/qmk_firmware/tree/0.13.0/keyboards/durgod/k320) has been reworked in anticipation of additional Durgod keyboards gaining QMK support.
Additionally, the `crkbd/rev1/legacy` keyboard has been removed.
### Bootmagic Deprecation and Refactor ([#12172](https://github.com/qmk/qmk_firmware/pull/12172)) :id=bootmagic-deprecation-and-refactor
QMK has decided to deprecate the full Bootmagic feature and leave Bootmagic Lite as the only remaining option.
This pull request changes the behavior of `BOOTMAGIC_ENABLE` such that specifying `BOOTMAGIC_ENABLE = yes` enables Bootmagic Lite instead of full Bootmagic.
If attempts to use Bootmagic functionality result in unexpected behavior, check your `rules.mk` file and change the `BOOTMAGIC_ENABLE` setting to specify either `lite` or `full`.
#### Tentative Deprecation Schedule
This is the current planned roadmap for the behavior of `BOOTMAGIC_ENABLE`:
- From 2021 May 29, setting `BOOTMAGIC_ENABLE = yes` will enable Bootmagic Lite instead of full Bootmagic.
- From 2021 Aug 28, `BOOTMAGIC_ENABLE` must be either `yes`, `lite`, or `no`– setting `BOOTMAGIC_ENABLE = full` will cause compilation to fail.
- From 2021 Nov 27, `BOOTMAGIC_ENABLE` must be either `yes` or `no`– setting `BOOTMAGIC_ENABLE = lite` will cause compilation to fail.
### Removal of LAYOUT_kc ([#12160](https://github.com/qmk/qmk_firmware/pull/12160)) :id=removal-of-layout-kc
We've removed support for `LAYOUT_kc` macros, if your keymap uses one you will need to update it use a regular `LAYOUT` macro.
### Encoder callbacks are now boolean ([#12805](https://github.com/qmk/qmk_firmware/pull/12805), [#12985](https://github.com/qmk/qmk_firmware/pull/12985)) :id=encoder-callback-boolean
To allow for keyboards to override (or not) keymap level code the `encoder_update_kb` function has been changed from `void` to `bool`. You will need to update your function definition to reflect this and ensure that you return a `true` or `false` value.
* Fix connection issue in split keyboards when slave and OLED display are connected via I2C (fixes #9335) ([#11487](https://github.com/qmk/qmk_firmware/pull/11487))
* Terrazzo: Fix wrong LED Matrix function names ([#12561](https://github.com/qmk/qmk_firmware/pull/12561))
* Apply the "NO_LIMITED_CONTROLLER_CONNECT" fix to atmega16u2 ([#12482](https://github.com/qmk/qmk_firmware/pull/12482))
* Enhancement of WPM feature ([#11727](https://github.com/qmk/qmk_firmware/pull/11727))
* Add Per Key functionality for AutoShift ([#11536](https://github.com/qmk/qmk_firmware/pull/11536))
* LED Matrix: Reactive effect buffers & advanced indicators ([#12588](https://github.com/qmk/qmk_firmware/pull/12588))
* LED Matrix: support for Split keyboards ([#12633](https://github.com/qmk/qmk_firmware/pull/12633))
* add setting to enable infinite timeout for leader key ([#6580](https://github.com/qmk/qmk_firmware/pull/6580), [#12721](https://github.com/qmk/qmk_firmware/pull/12721 "Fix bad PR merge for #6580"))
* Update ADC driver for STM32F1xx, STM32F3xx, STM32F4xx ([#12403](https://github.com/qmk/qmk_firmware/pull/12403))
* Add initial support for tinyuf2 bootloader (when hosted on F411 blackpill) ([#12600](https://github.com/qmk/qmk_firmware/pull/12600))
* Add support for STM32F446 MCU ([#12619](https://github.com/qmk/qmk_firmware/pull/12619))
* Add STM32L433 and L443 support ([#12063](https://github.com/qmk/qmk_firmware/pull/12063))
* Added OLED fade out support ([#12086](https://github.com/qmk/qmk_firmware/pull/12086))
* New command: `qmk console` ([#12828](https://github.com/qmk/qmk_firmware/pull/12828))
* LED Matrix: Effects! ([#12651](https://github.com/qmk/qmk_firmware/pull/12651))
* Add setup, clone, and env to the list of commands we allow even with broken modules ([#12868](https://github.com/qmk/qmk_firmware/pull/12868))
* LED Matrix: Documentation ([#12685](https://github.com/qmk/qmk_firmware/pull/12685))
* Add function to allow repeated blinking of one layer ([#12237](https://github.com/qmk/qmk_firmware/pull/12237))
* Add support for up to 4 IS31FL3733 drivers ([#12342](https://github.com/qmk/qmk_firmware/pull/12342))
* Convert Encoder callbacks to be boolean functions ([#12805](https://github.com/qmk/qmk_firmware/pull/12805), [#12985](https://github.com/qmk/qmk_firmware/pull/12985))
* [Keymap] Update to Drashna keymap and user code (based on develop) ([#12936](https://github.com/qmk/qmk_firmware/pull/12936))
* Add Full-duplex serial driver for ARM boards ([#9842](https://github.com/qmk/qmk_firmware/pull/9842))
* Backlight: add defines for default level and breathing state ([#12560](https://github.com/qmk/qmk_firmware/pull/12560), [#13024](https://github.com/qmk/qmk_firmware/pull/13024))
* Add dire message about LUFA mass storage bootloader ([#13014](https://github.com/qmk/qmk_firmware/pull/13014))
### Clean-ups and Optimizations :id=core-optimizations
* Overhaul bootmagic logic to have single entrypoint ([#8532](https://github.com/qmk/qmk_firmware/pull/8532))
* Refactor of USB code within split_common ([#11890](https://github.com/qmk/qmk_firmware/pull/11890))
* Begin the process of deprecating `bin/qmk` in favor of the global CLI ([#12109](https://github.com/qmk/qmk_firmware/pull/12109))
* LED Matrix: decouple from Backlight ([#12054](https://github.com/qmk/qmk_firmware/pull/12054))
* Move gpio wait logic to wait.h ([#12067](https://github.com/qmk/qmk_firmware/pull/12067))
* LED Matrix: Clean up includes ([#12197](https://github.com/qmk/qmk_firmware/pull/12197))
* Consistently use bin/qmk when that script is called ([#12286](https://github.com/qmk/qmk_firmware/pull/12286))
* LED Matrix: Additional common_features.mk tweaks ([#12187](https://github.com/qmk/qmk_firmware/pull/12187))
* LED Matrix: Fix up eeconfig code ([#12327](https://github.com/qmk/qmk_firmware/pull/12327))
* Big quantum_keycodes cleanup ([#12249](https://github.com/qmk/qmk_firmware/pull/12249))
* Fix up builds that are now too big for `develop` branch. ([#12495](https://github.com/qmk/qmk_firmware/pull/12495))
* [Keyboard] kint36: switch to sym_eager_pk debouncing ([#12626](https://github.com/qmk/qmk_firmware/pull/12626))
* [Keyboard] kint2pp: reduce input latency by ≈10ms ([#12625](https://github.com/qmk/qmk_firmware/pull/12625))
* eeprom driver: Refactor where eeprom driver initialisation (and EEPROM emulation initialisation) occurs to make it non-target-specific. ([#12671](https://github.com/qmk/qmk_firmware/pull/12671))
* Change RGB/LED Matrix to use a simple define for USB suspend ([#12697](https://github.com/qmk/qmk_firmware/pull/12697), [#12770](https://github.com/qmk/qmk_firmware/pull/12770 "Fixing transport's led/rgb matrix suspend state logic"))
