2021 May 29 Breaking Changes Update (#13034)

* Add Per Key functionality for AutoShift (#11536)

* LED Matrix: Reactive effect buffers & advanced indicators (#12588)

* [Keyboard] kint36: switch to sym_eager_pk debouncing (#12626)

* [Keyboard] kint2pp: reduce input latency by ≈10ms (#12625)

* LED Matrix: Split (#12633)

* [CI] Format code according to conventions (#12650)

* feat: infinite timeout for leader key (#6580)

* feat: implement leader_no_timeout logic

* docs(leader_key): infinite leader timeout docs

* Format code according to conventions (#12680)

* Update ADC driver for STM32F1xx, STM32F3xx, STM32F4xx (#12403)

* Fix default ADC_RESOLUTION for ADCv3 (and ADCv4)

Recent ChibiOS update removed ADC_CFGR1_RES_10BIT from the ADCv3 headers
(that macro should not have been there, because ADCv3 has CFGR instead of
CFGR1).  Fix the default value for ADC_RESOLUTION to use ADC_CFGR_RES_10BITS
if it is defined (that name is used for ADCv3 and ADCv4).

* Update ADC docs to match the actually used resolution

ADC driver for ChibiOS actually uses the 10-bit resolution by default
(probably to match AVR); fix the documentation accordingly.  Also add
both ADC_CFGR_RES_10BITS and ADC_CFGR1_RES_10BIT constants (these names
differ according to the ADC implementation in the particular MCU).

* Fix pinToMux() for B12 and B13 on STM32F3xx

Testing on STM32F303CCT6 revealed that the ADC mux values for B12 and
B13 pins were wrong.

* Add support for all possible analog pins on STM32F1xx

Added ADC mux values for pins A0...A7, B0, B1, C0...C5 on STM32F1xx
(they are the same at least for STM32F103x8 and larger F103 devices, and
also F102, F105, F107 families).  Actually tested on STM32F103C8T6
(therefore pins C0...C5 were not tested).

Pins F6...F10, which are present on STM32F103x[C-G] in 144-pin packages,
cannot be supported at the moment, because those pins are connected only
to ADC3, but the ChibiOS ADC driver for STM32F1xx supports only ADC1.

* Add support for all possible analog pins on STM32F4xx

Added ADC mux values for pins A0...A7, B0, B1, C0...C5 and optionally
F3...F10 (if STM32_ADC_USE_ADC3 is enabled).  These mux values are
apparently the same for all F4xx devices, except some smaller devices may
not have ADC3.

Actually tested on STM32F401CCU6, STM32F401CEU6, STM32F411CEU6 (using
various WeAct “Blackpill” boards); only pins A0...A7, B0, B1 were tested.

Pins F3...F10 are inside `#if STM32_ADC_USE_ADC3` because some devices
which don't have ADC3 also don't have the GPIOF port, therefore the code
which refers to Fx pins does not compile.

* Fix STM32F3xx ADC mux table in documentation

The ADC driver documentation had some errors in the mux table for STM32F3xx.
Fix this table to match the datasheet and the actual code (mux settings for
B12 and B13 were also tested on a real STM32F303CCT6 chip).

* Add STM32F1xx ADC pins to the documentation

* Add STM32F4xx ADC pins to the documentation

* Add initial support for tinyuf2 bootloader (when hosted on F411 blackpill) (#12600)

* Add support for jumping to tinyuf2 bootloader. Adds blackpill UF2 example.

* Update flashing.md

* Update chconf.h

* Update config.h

* Update halconf.h

* Update mcuconf.h

* eeprom driver: Refactor where eeprom driver initialisation (and EEPROM emulation initialisation) occurs to make it non-target-specific. (#12671)

* Add support for MCU = STM32F446 (#12619)

* Add support for MCU = STM32F446

* Update platforms/chibios/GENERIC_STM32_F446XE/configs/config.h

* Restore mcuconf.h to the one used by RT-STM32F446RE-NUCLEO64

* stm32f446: update mcuconf.h and board.h for 16MHz operation, with USB enabled, and other peripherals disabled.

* Format code according to conventions (#12682)

* Format code according to conventions (#12687)

* Add STM32L433 and L443 support (#12063)

* initial L433 commit

* change to XC

* fix L433

* disable all peripherals

* update system and peripheral clocks

* 433 change

* use its own board  files

* revert its own board files

* l433 specific change

* fix stm32l432xx define

* remove duplicate #define

* fix bootloader jump

* move to L443xx and add i2c2, spi2, usart3 to mcuconf.h

* move to L443

* move to L443

* fix sdmmc in mcuconf.h

* include STM32L443

* add L443

* Include L443 in compatible microcontrollers

* Include L443 in compatible microcontrollers

* Update config bootloader jump description

* Update ChibiOS define reasoning

* Update quantum/mcu_selection.mk

* fix git conflict

* Updated Function96 with V2 files and removed chconf.h and halconf.h (#12613)

* Fix bad PR merge for #6580. (#12721)

* Change RGB/LED Matrix to use a simple define for USB suspend (#12697)

* [CI] Format code according to conventions (#12731)

* Fixing transport's led/rgb matrix suspend state logic (#12770)

* [CI] Format code according to conventions (#12772)

* Fix comment parsing (#12750)

* Added OLED fade out support (#12086)

* fix some references to bin/qmk that slipped in (#12832)

* Resolve a number of warnings in `qmk generate-api` (#12833)

* New command: qmk console (#12828)

* stash poc

* stash

* tidy up implementation

* Tidy up slightly for review

* Tidy up slightly for review

* Bodge environment to make tests pass

* Refactor away from asyncio due to windows issues

* Filter devices

* align vid/pid printing

* Add hidapi to the installers

* start preparing for multiple hid_listeners

* udev rules for hid_listen

* refactor to move closer to end state

* very basic implementation of the threaded model

* refactor how vid/pid/index are supplied and parsed

* windows improvements

* read the report directly when usage page isn't available

* add per-device colors, the choice to show names or numbers, and refactor

* add timestamps

* Add support for showing bootloaders

* tweak the color for bootloaders

* Align bootloader disconnect with connect color

* add support for showing all bootloaders

* fix the pyusb check

* tweaks

* fix exception

* hide a stack trace behind -v

* add --no-bootloaders option

* add documentation for qmk console

* Apply suggestions from code review

* pyformat

* clean up and flesh out KNOWN_BOOTLOADERS

* Remove pointless SERIAL_LINK_ENABLE rules (#12846)

* Make Swap Hands use PROGMEM (#12284)

This converts the array that the Swap Hands feature uses to use PROGMEM,
and to read from that array, as such. Since this array never changes at
runtime, there is no reason to keep it in memory. Especially for AVR
boards, as memory is a precious resource.

* Fix another bin/qmk reference (#12856)

* [Keymap] Turn OLED off on suspend in soundmonster keymap (#10419)

* Fixup build errors on `develop` branch. (#12723)

* LED Matrix: Effects! (#12651)

* Fix syntax error when compiling for ARM (#12866)

* Remove KEYMAP and LAYOUT_kc (#12160)

* alias KEYMAP to LAYOUT

* remove KEYMAP and LAYOUT_kc

* Add setup, clone, and env to the list of commands we allow even with broken modules (#12868)

* Rename `point_t` -> `led_point_t` (#12864)

* [Keyboard] updated a vendor name / fixed minor keymap issues (#12881)

* Add missing LED Matrix suspend code to suspend.c (#12878)

* LED Matrix: Documentation (#12685)

* Deprecate `send_unicode_hex_string()` (#12602)

* Fix spelling mistake regarding LED Matrix in split_common. (#12888)

* [Keymap] Fix QWERTY/DVORAK status output for kzar keymap (#12895)

* Use milc.subcommand.config instead of qmk.cli.config (#12915)

* Use milc.subcommand.config instead

* pyformat

* remove the config test

* Add function to allow repeated blinking of one layer (#12237)

* Implement function rgblight_blink_layer_repeat to allow repeated blinking of one layer at a time

* Update doc

* Rework rgblight blinking according to requested change

* optimize storage

* Fixup housekeeping from being invoked twice per loop. (#12933)

* matrix: wait for row signal to go HIGH for every row (#12945)

I noticed this discrepancy (last row of the matrix treated differently than the
others) when optimizing the input latency of my keyboard controller, see also
https://michael.stapelberg.ch/posts/2021-05-08-keyboard-input-latency-qmk-kinesis/

Before this commit, when tuning the delays I noticed ghost key presses when
pressing the F2 key, which is on the last row of the keyboard matrix: the
dead_grave key, which is on the first row of the keyboard matrix, would be
incorrectly detected as pressed.

After this commit, all keyboard matrix rows are interpreted correctly.

I suspect that my setup is more susceptible to this nuance than others because I
use GPIO_INPUT_PIN_DELAY=0 and hence don’t have another delay that might mask
the problem.

* ensure we do not conflict with existing keymap aliases (#12976)

* Add support for up to 4 IS31FL3733 drivers (#12342)

* Convert Encoder callbacks to be boolean functions (#12805)

* [Keyboard] Fix Terrazzo build failure (#12977)

* Do not hard set config in CPTC files (#11864)

* [Keyboard] Corne - Remove legacy revision support (#12226)

* [Keymap] Update to Drashna keymap and user code (based on develop) (#12936)

* Add Full-duplex serial driver for ARM boards (#9842)

* Document LED_MATRIX_FRAMEBUFFER_EFFECTS (#12987)

* Backlight: add defines for default level and breathing state (#12560)

* Add dire message about LUFA mass storage bootloader (#13014)

* [Keyboard] Remove redundant legacy and common headers for crkbd (#13023)

Was causing compiler errors on some systems.

* Fix keyboards/keymaps for boolean encoder callback changes (#12985)

* `backlight.c`: include `eeprom.h` (#13024)

* Add changelog for 2021-05-29 Breaking Changes merge (#12939)

* Add ChangeLog for 2021-05-29 Breaking Changes Merge: initial version

* Add recent develop changes

* Sort recent develop changes

* Remove sections for ChibiOS changes per tzarc

No ChibiOS changes this round.

* Add and sort recent develop changes

* add notes about keyboard moves/deletions

* import changelog for PR 12172

Documents the change to BOOTMAGIC_ENABLE.

* update section headings

* re-sort changelog

* add additional note regarding Bootmagic changes

* remove changelog timestamp

* update dates in main Breaking Changes docs

* fix broken section anchors in previous changelogs

* add link to backlight/eeprom patch to changelog

* highlight some more changes

* link PRs from section headers

* Restore standard readme

* run: qmk cformat --core-only

18 files changed, 1 insertions, 2188 deletions

diff --git a/keyboards/crkbd/rev1/legacy/config.h b/keyboards/crkbd/rev1/legacy/config.h
deleted file mode 100644
index e95f49125a..0000000000
--- a/keyboards/crkbd/rev1/legacy/config.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
-Copyright 2012 Jun Wako <wakojun@gmail.com>
-Copyright 2015 Jack Humbert
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#pragma once
-
-#include "serial_config.h"
-
diff --git a/keyboards/crkbd/rev1/legacy/i2c.c b/keyboards/crkbd/rev1/legacy/i2c.c
deleted file mode 100644
index 7b45c3f866..0000000000
--- a/keyboards/crkbd/rev1/legacy/i2c.c
+++ /dev/null
@@ -1,162 +0,0 @@
-#include <util/twi.h>
-#include <avr/io.h>
-#include <stdlib.h>
-#include <avr/interrupt.h>
-#include <util/twi.h>
-#include <stdbool.h>
-#include "i2c.h"
-
-#if defined(USE_I2C) || defined(USE_MATRIX_I2C)
-
-// Limits the amount of we wait for any one i2c transaction.
-// Since were running SCL line 100kHz (=> 10μs/bit), and each transactions is
-// 9 bits, a single transaction will take around 90μs to complete.
-//
-// (F_CPU/SCL_CLOCK)  =>  # of μC cycles to transfer a bit
-// poll loop takes at least 8 clock cycles to execute
-#define I2C_LOOP_TIMEOUT (9+1)*(F_CPU/SCL_CLOCK)/8
-
-#define BUFFER_POS_INC() (slave_buffer_pos = (slave_buffer_pos+1)%SLAVE_BUFFER_SIZE)
-
-volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
-
-static volatile uint8_t slave_buffer_pos;
-static volatile bool slave_has_register_set = false;
-
-// Wait for an i2c operation to finish
-inline static
-void i2c_delay(void) {
-  uint16_t lim = 0;
-  while(!(TWCR & (1<<TWINT)) && lim < I2C_LOOP_TIMEOUT)
-    lim++;
-
-  // easier way, but will wait slightly longer
-  // _delay_us(100);
-}
-
-// Setup twi to run at 100kHz or 400kHz (see ./i2c.h SCL_CLOCK)
-void i2c_master_init(void) {
-  // no prescaler
-  TWSR = 0;
-  // Set TWI clock frequency to SCL_CLOCK. Need TWBR>10.
-  // Check datasheets for more info.
-  TWBR = ((F_CPU/SCL_CLOCK)-16)/2;
-}
-
-// Start a transaction with the given i2c slave address. The direction of the
-// transfer is set with I2C_READ and I2C_WRITE.
-// returns: 0 => success
-//          1 => error
-uint8_t i2c_master_start(uint8_t address) {
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTA);
-
-  i2c_delay();
-
-  // check that we started successfully
-  if ( (TW_STATUS != TW_START) && (TW_STATUS != TW_REP_START))
-    return 1;
-
-  TWDR = address;
-  TWCR = (1<<TWINT) | (1<<TWEN);
-
-  i2c_delay();
-
-  if ( (TW_STATUS != TW_MT_SLA_ACK) && (TW_STATUS != TW_MR_SLA_ACK) )
-    return 1; // slave did not acknowledge
-  else
-    return 0; // success
-}
-
-
-// Finish the i2c transaction.
-void i2c_master_stop(void) {
-  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
-
-  uint16_t lim = 0;
-  while(!(TWCR & (1<<TWSTO)) && lim < I2C_LOOP_TIMEOUT)
-    lim++;
-}
-
-// Write one byte to the i2c slave.
-// returns 0 => slave ACK
-//         1 => slave NACK
-uint8_t i2c_master_write(uint8_t data) {
-  TWDR = data;
-  TWCR = (1<<TWINT) | (1<<TWEN);
-
-  i2c_delay();
-
-  // check if the slave acknowledged us
-  return (TW_STATUS == TW_MT_DATA_ACK) ? 0 : 1;
-}
-
-// Read one byte from the i2c slave. If ack=1 the slave is acknowledged,
-// if ack=0 the acknowledge bit is not set.
-// returns: byte read from i2c device
-uint8_t i2c_master_read(int ack) {
-  TWCR = (1<<TWINT) | (1<<TWEN) | (ack<<TWEA);
-
-  i2c_delay();
-  return TWDR;
-}
-
-void i2c_reset_state(void) {
-  TWCR = 0;
-}
-
-void i2c_slave_init(uint8_t address) {
-  TWAR = address << 0; // slave i2c address
-  // TWEN  - twi enable
-  // TWEA  - enable address acknowledgement
-  // TWINT - twi interrupt flag
-  // TWIE  - enable the twi interrupt
-  TWCR = (1<<TWIE) | (1<<TWEA) | (1<<TWINT) | (1<<TWEN);
-}
-
-ISR(TWI_vect);
-
-ISR(TWI_vect) {
-  uint8_t ack = 1;
-  switch(TW_STATUS) {
-    case TW_SR_SLA_ACK:
-      // this device has been addressed as a slave receiver
-      slave_has_register_set = false;
-      break;
-
-    case TW_SR_DATA_ACK:
-      // this device has received data as a slave receiver
-      // The first byte that we receive in this transaction sets the location
-      // of the read/write location of the slaves memory that it exposes over
-      // i2c.  After that, bytes will be written at slave_buffer_pos, incrementing
-      // slave_buffer_pos after each write.
-      if(!slave_has_register_set) {
-        slave_buffer_pos = TWDR;
-        // don't acknowledge the master if this memory loctaion is out of bounds
-        if ( slave_buffer_pos >= SLAVE_BUFFER_SIZE ) {
-          ack = 0;
-          slave_buffer_pos = 0;
-        }
-        slave_has_register_set = true;
-      } else {
-        i2c_slave_buffer[slave_buffer_pos] = TWDR;
-        BUFFER_POS_INC();
-      }
-      break;
-
-    case TW_ST_SLA_ACK:
-    case TW_ST_DATA_ACK:
-      // master has addressed this device as a slave transmitter and is
-      // requesting data.
-      TWDR = i2c_slave_buffer[slave_buffer_pos];
-      BUFFER_POS_INC();
-      break;
-
-    case TW_BUS_ERROR: // something went wrong, reset twi state
-      TWCR = 0;
-    default:
-      break;
-  }
-  // Reset everything, so we are ready for the next TWI interrupt
-  TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN);
-}
-#endif
diff --git a/keyboards/crkbd/rev1/legacy/i2c.h b/keyboards/crkbd/rev1/legacy/i2c.h
deleted file mode 100644
index 710662c7ab..0000000000
--- a/keyboards/crkbd/rev1/legacy/i2c.h
+++ /dev/null
@@ -1,46 +0,0 @@
-#pragma once
-
-#include <stdint.h>
-
-#ifndef F_CPU
-#define F_CPU 16000000UL
-#endif
-
-#define I2C_READ 1
-#define I2C_WRITE 0
-
-#define I2C_ACK 1
-#define I2C_NACK 0
-
-#define SLAVE_BUFFER_SIZE 0x10
-
-// i2c SCL clock frequency 400kHz
-#define SCL_CLOCK  400000L
-
-extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
-
-void i2c_master_init(void);
-uint8_t i2c_master_start(uint8_t address);
-void i2c_master_stop(void);
-uint8_t i2c_master_write(uint8_t data);
-uint8_t i2c_master_read(int);
-void i2c_reset_state(void);
-void i2c_slave_init(uint8_t address);
-
-
-static inline unsigned char i2c_start_read(unsigned char addr) {
-  return i2c_master_start((addr << 1) | I2C_READ);
-}
-
-static inline unsigned char i2c_start_write(unsigned char addr) {
-  return i2c_master_start((addr << 1) | I2C_WRITE);
-}
-
-// from SSD1306 scrips
-extern unsigned char i2c_rep_start(unsigned char addr);
-extern void i2c_start_wait(unsigned char addr);
-extern unsigned char i2c_readAck(void);
-extern unsigned char i2c_readNak(void);
-extern unsigned char i2c_read(unsigned char ack);
-
-#define i2c_read(ack)  (ack) ? i2c_readAck() : i2c_readNak();
diff --git a/keyboards/crkbd/rev1/legacy/legacy.c b/keyboards/crkbd/rev1/legacy/legacy.c
deleted file mode 100644
index 595ff1eaf7..0000000000
--- a/keyboards/crkbd/rev1/legacy/legacy.c
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "legacy.h"
diff --git a/keyboards/crkbd/rev1/legacy/legacy.h b/keyboards/crkbd/rev1/legacy/legacy.h
deleted file mode 100644
index 08dfcefbc1..0000000000
--- a/keyboards/crkbd/rev1/legacy/legacy.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#pragma once
-
-#include "rev1.h"
-
-extern uint8_t is_master;
\ No newline at end of file
diff --git a/keyboards/crkbd/rev1/legacy/matrix.c b/keyboards/crkbd/rev1/legacy/matrix.c
deleted file mode 100644
index 371b1913e1..0000000000
--- a/keyboards/crkbd/rev1/legacy/matrix.c
+++ /dev/null
@@ -1,397 +0,0 @@
-/*
-Copyright 2012 Jun Wako <wakojun@gmail.com>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-/*
- * scan matrix
- */
-#include <stdint.h>
-#include <stdbool.h>
-#include <string.h>
-#include <avr/io.h>
-#include <avr/wdt.h>
-#include <avr/interrupt.h>
-#include <util/delay.h>
-#include "print.h"
-#include "debug.h"
-#include "util.h"
-#include "matrix.h"
-#include "split_util.h"
-#include "quantum.h"
-
-#ifdef USE_MATRIX_I2C
-#  include "i2c.h"
-#else // USE_SERIAL
-#  include "split_scomm.h"
-#endif
-
-#ifndef DEBOUNCE
-#  define DEBOUNCE	5
-#endif
-
-#define ERROR_DISCONNECT_COUNT 5
-
-static uint8_t debouncing = DEBOUNCE;
-static const int ROWS_PER_HAND = MATRIX_ROWS/2;
-static uint8_t error_count = 0;
-uint8_t is_master = 0 ;
-
-static const uint8_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
-static const uint8_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
-
-/* matrix state(1:on, 0:off) */
-static matrix_row_t matrix[MATRIX_ROWS];
-static matrix_row_t matrix_debouncing[MATRIX_ROWS];
-
-static matrix_row_t read_cols(void);
-static void init_cols(void);
-static void unselect_rows(void);
-static void select_row(uint8_t row);
-static uint8_t matrix_master_scan(void);
-
-
-__attribute__ ((weak))
-void matrix_init_kb(void) {
-    matrix_init_user();
-}
-
-__attribute__ ((weak))
-void matrix_scan_kb(void) {
-    matrix_scan_user();
-}
-
-__attribute__ ((weak))
-void matrix_init_user(void) {
-}
-
-__attribute__ ((weak))
-void matrix_scan_user(void) {
-}
-
-inline
-uint8_t matrix_rows(void)
-{
-    return MATRIX_ROWS;
-}
-
-inline
-uint8_t matrix_cols(void)
-{
-    return MATRIX_COLS;
-}
-
-void tx_rx_leds_init(void)
-{
-#ifndef NO_DEBUG_LEDS
-    setPinOutput(B0);
-    setPinOutput(D5);
-    writePinHigh(B0);
-    writePinHigh(D5);
-#endif
-}
-
-void tx_led_on(void)
-{
-#ifndef NO_DEBUG_LEDS
-    writePinLow(D5);
-#endif
-}
-
-void tx_led_off(void)
-{
-#ifndef NO_DEBUG_LEDS
-    writePinHigh(D5);
-#endif
-}
-
-void rx_led_on(void)
-{
-#ifndef NO_DEBUG_LEDS
-    writePinLow(B0);
-#endif
-}
-
-void rx_led_off(void)
-{
-#ifndef NO_DEBUG_LEDS
-    writePinHigh(B0);
-#endif
-}
-
-
-void matrix_init(void)
-{
-    split_keyboard_setup();
-
-    // initialize row and col
-    unselect_rows();
-    init_cols();
-
-    tx_rx_leds_init();
-
-    // initialize matrix state: all keys off
-    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
-        matrix[i] = 0;
-        matrix_debouncing[i] = 0;
-    }
-
-    is_master = has_usb();
-
-    matrix_init_quantum();
-}
-
-uint8_t _matrix_scan(void)
-{
-    bool changed = false;
-    // Right hand is stored after the left in the matirx so, we need to offset it
-    int offset = isLeftHand ? 0 : (ROWS_PER_HAND);
-
-    for (uint8_t i = 0; i < ROWS_PER_HAND; i++) {
-        select_row(i);
-        _delay_us(30);  // without this wait read unstable value.
-        matrix_row_t cols = read_cols();
-        if (matrix_debouncing[i+offset] != cols) {
-            changed = true;
-            matrix_debouncing[i+offset] = cols;
-            debouncing = DEBOUNCE;
-        }
-        unselect_rows();
-    }
-
-    if (debouncing) {
-        if (--debouncing) {
-            _delay_ms(1);
-        } else {
-            for (uint8_t i = 0; i < ROWS_PER_HAND; i++) {
-                matrix[i+offset] = matrix_debouncing[i+offset];
-            }
-        }
-    }
-
-    return changed;
-}
-
-#ifdef USE_MATRIX_I2C
-
-// Get rows from other half over i2c
-int i2c_transaction(void) {
-    int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
-
-    int err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_WRITE);
-    if (err) goto i2c_error;
-
-    // start of matrix stored at 0x00
-    err = i2c_master_write(0x00);
-    if (err) goto i2c_error;
-
-    // Start read
-    err = i2c_master_start(SLAVE_I2C_ADDRESS + I2C_READ);
-    if (err) goto i2c_error;
-
-    if (!err) {
-        int i;
-        for (i = 0; i < ROWS_PER_HAND-1; ++i) {
-            matrix[slaveOffset+i] = i2c_master_read(I2C_ACK);
-        }
-        matrix[slaveOffset+i] = i2c_master_read(I2C_NACK);
-        i2c_master_stop();
-    } else {
-i2c_error: // the cable is disconnceted, or something else went wrong
-        i2c_reset_state();
-        return err;
-    }
-
-    return 0;
-}
-
-#else // USE_SERIAL
-
-int serial_transaction(int master_changed) {
-    int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
-#ifdef SERIAL_USE_MULTI_TRANSACTION
-    int ret=serial_update_buffers(master_changed);
-#else
-    int ret=serial_update_buffers();
-#endif
-    if (ret ) {
-        if(ret==2) rx_led_on();
-        return 1;
-    }
-    rx_led_off();
-    memcpy(&matrix[slaveOffset],
-        (void *)serial_slave_buffer, SERIAL_SLAVE_BUFFER_LENGTH);
-    return 0;
-}
-#endif
-
-uint8_t matrix_scan(void)
-{
-    bool changed = false;
-    if (is_master) {
-        changed |= matrix_master_scan();
-    }else{
-        changed |= matrix_slave_scan();
-        int offset = (isLeftHand) ? ROWS_PER_HAND : 0;
-        memcpy(&matrix[offset],
-               (void *)serial_master_buffer, SERIAL_MASTER_BUFFER_LENGTH);
-        matrix_scan_quantum();
-    }
-    return (uint8_t) changed;
-}
-
-
-uint8_t matrix_master_scan(void) {
-
-    int ret = _matrix_scan();
-    int mchanged = 1;
-
-    int offset = (isLeftHand) ? 0 : ROWS_PER_HAND;
-
-#ifdef USE_MATRIX_I2C
-//    for (int i = 0; i < ROWS_PER_HAND; ++i) {
-        /* i2c_slave_buffer[i] = matrix[offset+i]; */
-//        i2c_slave_buffer[i] = matrix[offset+i];
-//    }
-#else // USE_SERIAL
-  #ifdef SERIAL_USE_MULTI_TRANSACTION
-    mchanged = memcmp((void *)serial_master_buffer,
-		      &matrix[offset], SERIAL_MASTER_BUFFER_LENGTH);
-  #endif
-    memcpy((void *)serial_master_buffer,
-	   &matrix[offset], SERIAL_MASTER_BUFFER_LENGTH);
-#endif
-
-#ifdef USE_MATRIX_I2C
-    if( i2c_transaction() ) {
-#else // USE_SERIAL
-    if( serial_transaction(mchanged) ) {
-#endif
-        // turn on the indicator led when halves are disconnected
-        tx_led_on();
-
-        error_count++;
-
-        if (error_count > ERROR_DISCONNECT_COUNT) {
-            // reset other half if disconnected
-            int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;
-            for (int i = 0; i < ROWS_PER_HAND; ++i) {
-                matrix[slaveOffset+i] = 0;
-            }
-        }
-    } else {
-        // turn off the indicator led on no error
-        tx_led_off();
-        error_count = 0;
-    }
-    matrix_scan_quantum();
-    return ret;
-}
-
-uint8_t matrix_slave_scan(void) {
-    int ret = _matrix_scan();
-
-    int offset = (isLeftHand) ? 0 : ROWS_PER_HAND;
-
-#ifdef USE_MATRIX_I2C
-    for (int i = 0; i < ROWS_PER_HAND; ++i) {
-        /* i2c_slave_buffer[i] = matrix[offset+i]; */
-        i2c_slave_buffer[i] = matrix[offset+i];
-    }
-#else // USE_SERIAL
-  #ifdef SERIAL_USE_MULTI_TRANSACTION
-    int change = 0;
-  #endif
-    for (int i = 0; i < ROWS_PER_HAND; ++i) {
-  #ifdef SERIAL_USE_MULTI_TRANSACTION
-        if( serial_slave_buffer[i] != matrix[offset+i] )
-        change = 1;
-  #endif
-        serial_slave_buffer[i] = matrix[offset+i];
-    }
-  #ifdef SERIAL_USE_MULTI_TRANSACTION
-    slave_buffer_change_count += change;
-  #endif
-#endif
-    return ret;
-}
-
-bool matrix_is_modified(void)
-{
-    if (debouncing) return false;
-    return true;
-}
-
-inline
-bool matrix_is_on(uint8_t row, uint8_t col)
-{
-    return (matrix[row] & ((matrix_row_t)1<<col));
-}
-
-inline
-matrix_row_t matrix_get_row(uint8_t row)
-{
-    return matrix[row];
-}
-
-void matrix_print(void)
-{
-    print("\nr/c 0123456789ABCDEF\n");
-    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
-        print_hex8(row); print(": ");
-        print_bin_reverse16(matrix_get_row(row));
-        print("\n");
-    }
-}
-
-uint8_t matrix_key_count(void)
-{
-    uint8_t count = 0;
-    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-        count += bitpop16(matrix[i]);
-    }
-    return count;
-}
-
-static void  init_cols(void)
-{
-    for(int x = 0; x < MATRIX_COLS; x++) {
-        _SFR_IO8((col_pins[x] >> 4) + 1) &=  ~_BV(col_pins[x] & 0xF);
-        _SFR_IO8((col_pins[x] >> 4) + 2) |= _BV(col_pins[x] & 0xF);
-    }
-}
-
-static matrix_row_t read_cols(void)
-{
-    matrix_row_t result = 0;
-    for(int x = 0; x < MATRIX_COLS; x++) {
-        result |= (_SFR_IO8(col_pins[x] >> 4) & _BV(col_pins[x] & 0xF)) ? 0 : (1 << x);
-    }
-    return result;
-}
-
-static void unselect_rows(void)
-{
-    for(int x = 0; x < ROWS_PER_HAND; x++) {
-        _SFR_IO8((row_pins[x] >> 4) + 1) &=  ~_BV(row_pins[x] & 0xF);
-        _SFR_IO8((row_pins[x] >> 4) + 2) |= _BV(row_pins[x] & 0xF);
-    }
-}
-
-static void select_row(uint8_t row)
-{
-    _SFR_IO8((row_pins[row] >> 4) + 1) |=  _BV(row_pins[row] & 0xF);
-    _SFR_IO8((row_pins[row] >> 4) + 2) &= ~_BV(row_pins[row] & 0xF);
-}
diff --git a/keyboards/crkbd/rev1/legacy/post_config.h b/keyboards/crkbd/rev1/legacy/post_config.h
deleted file mode 100644
index b3d6346cc8..0000000000
--- a/keyboards/crkbd/rev1/legacy/post_config.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#pragma once
-
-#ifdef SSD1306OLED
-#    define USE_I2C
-#endif
-
-#if defined(OLED_DRIVER_ENABLE) && (defined(USE_I2C) || defined(USE_MATRIX_I2C))
-#    error Cannot use both legacy i2c driver and new i2c_master driver at the same time. Undefine USE_I2C and/or USE_MATRIX_I2C
-#endif
diff --git a/keyboards/crkbd/rev1/legacy/rules.mk b/keyboards/crkbd/rev1/legacy/rules.mk
index 94c5fe0242..836587e45e 100644
--- a/keyboards/crkbd/rev1/legacy/rules.mk
+++ b/keyboards/crkbd/rev1/legacy/rules.mk
@@ -1,10 +1 @@
-CUSTOM_MATRIX = yes
-
-SRC += 	matrix.c \
-		split_util.c \
-		split_scomm.c
-
-QUANTUM_LIB_SRC += i2c.c serial.c
-
-# Disable unsupported hardware
-BACKLIGHT_SUPPORTED = no
+DEFAULT_FOLDER = crkbd/rev1
diff --git a/keyboards/crkbd/rev1/legacy/serial.c b/keyboards/crkbd/rev1/legacy/serial.c
deleted file mode 100644
index f6293c3dc2..0000000000
--- a/keyboards/crkbd/rev1/legacy/serial.c
+++ /dev/null
@@ -1,589 +0,0 @@
-/*
- * WARNING: be careful changing this code, it is very timing dependent
- *
- * 2018-10-28 checked
- *  avr-gcc 4.9.2
- *  avr-gcc 5.4.0
- *  avr-gcc 7.3.0
- */
-
-#ifndef F_CPU
-#define F_CPU 16000000
-#endif
-
-#include <avr/io.h>
-#include <avr/interrupt.h>
-#include <util/delay.h>
-#include <stddef.h>
-#include <stdbool.h>
-#include "serial.h"
-
-#ifdef SOFT_SERIAL_PIN
-
-#ifdef __AVR_ATmega32U4__
-  // if using ATmega32U4 I2C, can not use PD0 and PD1 in soft serial.
-  #ifdef USE_I2C
-    #if SOFT_SERIAL_PIN == D0 || SOFT_SERIAL_PIN == D1
-      #error Using ATmega32U4 I2C, so can not use PD0, PD1
-    #endif
-  #endif
-
-  #if SOFT_SERIAL_PIN >= D0 && SOFT_SERIAL_PIN <= D3
-    #define SERIAL_PIN_DDR   DDRD
-    #define SERIAL_PIN_PORT  PORTD
-    #define SERIAL_PIN_INPUT PIND
-    #if SOFT_SERIAL_PIN == D0
-      #define SERIAL_PIN_MASK _BV(PD0)
-      #define EIMSK_BIT       _BV(INT0)
-      #define EICRx_BIT       (~(_BV(ISC00) | _BV(ISC01)))
-      #define SERIAL_PIN_INTERRUPT INT0_vect
-    #elif  SOFT_SERIAL_PIN == D1
-      #define SERIAL_PIN_MASK _BV(PD1)
-      #define EIMSK_BIT       _BV(INT1)
-      #define EICRx_BIT       (~(_BV(ISC10) | _BV(ISC11)))
-      #define SERIAL_PIN_INTERRUPT INT1_vect
-    #elif  SOFT_SERIAL_PIN == D2
-      #define SERIAL_PIN_MASK _BV(PD2)
-      #define EIMSK_BIT       _BV(INT2)
-      #define EICRx_BIT       (~(_BV(ISC20) | _BV(ISC21)))
-      #define SERIAL_PIN_INTERRUPT INT2_vect
-    #elif  SOFT_SERIAL_PIN == D3
-      #define SERIAL_PIN_MASK _BV(PD3)
-      #define EIMSK_BIT       _BV(INT3)
-      #define EICRx_BIT       (~(_BV(ISC30) | _BV(ISC31)))
-      #define SERIAL_PIN_INTERRUPT INT3_vect
-    #endif
-  #elif  SOFT_SERIAL_PIN == E6
-    #define SERIAL_PIN_DDR   DDRE
-    #define SERIAL_PIN_PORT  PORTE
-    #define SERIAL_PIN_INPUT PINE
-    #define SERIAL_PIN_MASK  _BV(PE6)
-    #define EIMSK_BIT        _BV(INT6)
-    #define EICRx_BIT        (~(_BV(ISC60) | _BV(ISC61)))
-    #define SERIAL_PIN_INTERRUPT INT6_vect
-  #else
-  #error invalid SOFT_SERIAL_PIN value
-  #endif
-
-#else
- #error serial.c now support ATmega32U4 only
-#endif
-
-//////////////// for backward compatibility ////////////////////////////////
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-/* --- USE Simple API (OLD API, compatible with let's split serial.c) */
-  #if SERIAL_SLAVE_BUFFER_LENGTH > 0
-  uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
-  #endif
-  #if SERIAL_MASTER_BUFFER_LENGTH > 0
-  uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
-  #endif
-  uint8_t volatile status0 = 0;
-
-SSTD_t transactions[] = {
-    { (uint8_t *)&status0,
-  #if SERIAL_MASTER_BUFFER_LENGTH > 0
-      sizeof(serial_master_buffer), (uint8_t *)serial_master_buffer,
-  #else
-      0, (uint8_t *)NULL,
-  #endif
-  #if SERIAL_SLAVE_BUFFER_LENGTH > 0
-      sizeof(serial_slave_buffer), (uint8_t *)serial_slave_buffer
-  #else
-      0, (uint8_t *)NULL,
-  #endif
-  }
-};
-
-void serial_master_init(void)
-{ soft_serial_initiator_init(transactions, TID_LIMIT(transactions)); }
-
-void serial_slave_init(void)
-{ soft_serial_target_init(transactions, TID_LIMIT(transactions)); }
-
-// 0 => no error
-// 1 => slave did not respond
-// 2 => checksum error
-int serial_update_buffers()
-{
-    int result;
-    result = soft_serial_transaction();
-    return result;
-}
-
-#endif // end of Simple API (OLD API, compatible with let's split serial.c)
-////////////////////////////////////////////////////////////////////////////
-
-#define ALWAYS_INLINE __attribute__((always_inline))
-#define NO_INLINE __attribute__((noinline))
-#define _delay_sub_us(x)    __builtin_avr_delay_cycles(x)
-
-// parity check
-#define ODD_PARITY 1
-#define EVEN_PARITY 0
-#define PARITY EVEN_PARITY
-
-#ifdef SERIAL_DELAY
-  // custom setup in config.h
-  // #define TID_SEND_ADJUST 2
-  // #define SERIAL_DELAY 6             // micro sec
-  // #define READ_WRITE_START_ADJUST 30 // cycles
-  // #define READ_WRITE_WIDTH_ADJUST 8 // cycles
-#else
-// ============ Standard setups ============
-
-#ifndef SELECT_SOFT_SERIAL_SPEED
-#define SELECT_SOFT_SERIAL_SPEED 1
-//  0: about 189kbps
-//  1: about 137kbps (default)
-//  2: about 75kbps
-//  3: about 39kbps
-//  4: about 26kbps
-//  5: about 20kbps
-#endif
-
-#if __GNUC__ < 6
-  #define TID_SEND_ADJUST 14
-#else
-  #define TID_SEND_ADJUST 2
-#endif
-
-#if SELECT_SOFT_SERIAL_SPEED == 0
-  // Very High speed
-  #define SERIAL_DELAY 4             // micro sec
-  #if __GNUC__ < 6
-    #define READ_WRITE_START_ADJUST 33 // cycles
-    #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-  #else
-    #define READ_WRITE_START_ADJUST 34 // cycles
-    #define READ_WRITE_WIDTH_ADJUST 7 // cycles
-  #endif
-#elif SELECT_SOFT_SERIAL_SPEED == 1
-  // High speed
-  #define SERIAL_DELAY 6             // micro sec
-  #if __GNUC__ < 6
-    #define READ_WRITE_START_ADJUST 30 // cycles
-    #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-  #else
-    #define READ_WRITE_START_ADJUST 33 // cycles
-    #define READ_WRITE_WIDTH_ADJUST 7 // cycles
-  #endif
-#elif SELECT_SOFT_SERIAL_SPEED == 2
-  // Middle speed
-  #define SERIAL_DELAY 12            // micro sec
-  #define READ_WRITE_START_ADJUST 30 // cycles
-  #if __GNUC__ < 6
-    #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-  #else
-    #define READ_WRITE_WIDTH_ADJUST 7 // cycles
-  #endif
-#elif SELECT_SOFT_SERIAL_SPEED == 3
-  // Low speed
-  #define SERIAL_DELAY 24            // micro sec
-  #define READ_WRITE_START_ADJUST 30 // cycles
-  #if __GNUC__ < 6
-    #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-  #else
-    #define READ_WRITE_WIDTH_ADJUST 7 // cycles
-  #endif
-#elif SELECT_SOFT_SERIAL_SPEED == 4
-  // Very Low speed
-  #define SERIAL_DELAY 36            // micro sec
-  #define READ_WRITE_START_ADJUST 30 // cycles
-  #if __GNUC__ < 6
-    #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-  #else
-    #define READ_WRITE_WIDTH_ADJUST 7 // cycles
-  #endif
-#elif SELECT_SOFT_SERIAL_SPEED == 5
-  // Ultra Low speed
-  #define SERIAL_DELAY 48            // micro sec
-  #define READ_WRITE_START_ADJUST 30 // cycles
-  #if __GNUC__ < 6
-    #define READ_WRITE_WIDTH_ADJUST 3 // cycles
-  #else
-    #define READ_WRITE_WIDTH_ADJUST 7 // cycles
-  #endif
-#else
-#error invalid SELECT_SOFT_SERIAL_SPEED value
-#endif /* SELECT_SOFT_SERIAL_SPEED */
-#endif /* SERIAL_DELAY */
-
-#define SERIAL_DELAY_HALF1 (SERIAL_DELAY/2)
-#define SERIAL_DELAY_HALF2 (SERIAL_DELAY - SERIAL_DELAY/2)
-
-#define SLAVE_INT_WIDTH_US 1
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-  #define SLAVE_INT_RESPONSE_TIME SERIAL_DELAY
-#else
-  #define SLAVE_INT_ACK_WIDTH_UNIT 2
-  #define SLAVE_INT_ACK_WIDTH 4
-#endif
-
-static SSTD_t *Transaction_table = NULL;
-static uint8_t Transaction_table_size = 0;
-
-inline static void serial_delay(void) ALWAYS_INLINE;
-inline static
-void serial_delay(void) {
-  _delay_us(SERIAL_DELAY);
-}
-
-inline static void serial_delay_half1(void) ALWAYS_INLINE;
-inline static
-void serial_delay_half1(void) {
-  _delay_us(SERIAL_DELAY_HALF1);
-}
-
-inline static void serial_delay_half2(void) ALWAYS_INLINE;
-inline static
-void serial_delay_half2(void) {
-  _delay_us(SERIAL_DELAY_HALF2);
-}
-
-inline static void serial_output(void) ALWAYS_INLINE;
-inline static
-void serial_output(void) {
-  SERIAL_PIN_DDR |= SERIAL_PIN_MASK;
-}
-
-// make the serial pin an input with pull-up resistor
-inline static void serial_input_with_pullup(void) ALWAYS_INLINE;
-inline static
-void serial_input_with_pullup(void) {
-  SERIAL_PIN_DDR  &= ~SERIAL_PIN_MASK;
-  SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
-}
-
-inline static uint8_t serial_read_pin(void) ALWAYS_INLINE;
-inline static
-uint8_t serial_read_pin(void) {
-  return !!(SERIAL_PIN_INPUT & SERIAL_PIN_MASK);
-}
-
-inline static void serial_low(void) ALWAYS_INLINE;
-inline static
-void serial_low(void) {
-  SERIAL_PIN_PORT &= ~SERIAL_PIN_MASK;
-}
-
-inline static void serial_high(void) ALWAYS_INLINE;
-inline static
-void serial_high(void) {
-  SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
-}
-
-void soft_serial_initiator_init(SSTD_t *sstd_table, int sstd_table_size)
-{
-    Transaction_table = sstd_table;
-    Transaction_table_size = (uint8_t)sstd_table_size;
-    serial_output();
-    serial_high();
-}
-
-void soft_serial_target_init(SSTD_t *sstd_table, int sstd_table_size)
-{
-    Transaction_table = sstd_table;
-    Transaction_table_size = (uint8_t)sstd_table_size;
-    serial_input_with_pullup();
-
-    // Enable INT0-INT3,INT6
-    EIMSK |= EIMSK_BIT;
-#if SERIAL_PIN_MASK == _BV(PE6)
-    // Trigger on falling edge of INT6
-    EICRB &= EICRx_BIT;
-#else
-    // Trigger on falling edge of INT0-INT3
-    EICRA &= EICRx_BIT;
-#endif
-}
-
-// Used by the sender to synchronize timing with the reciver.
-static void sync_recv(void) NO_INLINE;
-static
-void sync_recv(void) {
-  for (uint8_t i = 0; i < SERIAL_DELAY*5 && serial_read_pin(); i++ ) {
-  }
-  // This shouldn't hang if the target disconnects because the
-  // serial line will float to high if the target does disconnect.
-  while (!serial_read_pin());
-}
-
-// Used by the reciver to send a synchronization signal to the sender.
-static void sync_send(void) NO_INLINE;
-static
-void sync_send(void) {
-  serial_low();
-  serial_delay();
-  serial_high();
-}
-
-// Reads a byte from the serial line
-static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) NO_INLINE;
-static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) {
-    uint8_t byte, i, p, pb;
-
-  _delay_sub_us(READ_WRITE_START_ADJUST);
-  for( i = 0, byte = 0, p = PARITY; i < bit; i++ ) {
-      serial_delay_half1();   // read the middle of pulses
-      if( serial_read_pin() ) {
-          byte = (byte << 1) | 1; p ^= 1;
-      } else {
-          byte = (byte << 1) | 0; p ^= 0;
-      }
-      _delay_sub_us(READ_WRITE_WIDTH_ADJUST);
-      serial_delay_half2();
-  }
-  /* recive parity bit */
-  serial_delay_half1();   // read the middle of pulses
-  pb = serial_read_pin();
-  _delay_sub_us(READ_WRITE_WIDTH_ADJUST);
-  serial_delay_half2();
-
-  *pterrcount += (p != pb)? 1 : 0;
-
-  return byte;
-}
-
-// Sends a byte with MSB ordering
-void serial_write_chunk(uint8_t data, uint8_t bit) NO_INLINE;
-void serial_write_chunk(uint8_t data, uint8_t bit) {
-    uint8_t b, p;
-    for( p = PARITY, b = 1<<(bit-1); b ; b >>= 1) {
-        if(data & b) {
-            serial_high(); p ^= 1;
-        } else {
-            serial_low();  p ^= 0;
-        }
-        serial_delay();
-    }
-    /* send parity bit */
-    if(p & 1) { serial_high(); }
-    else      { serial_low(); }
-    serial_delay();
-
-    serial_low(); // sync_send() / senc_recv() need raise edge
-}
-
-static void serial_send_packet(uint8_t *buffer, uint8_t size) NO_INLINE;
-static
-void serial_send_packet(uint8_t *buffer, uint8_t size) {
-  for (uint8_t i = 0; i < size; ++i) {
-    uint8_t data;
-    data = buffer[i];
-    sync_send();
-    serial_write_chunk(data,8);
-  }
-}
-
-static uint8_t serial_recive_packet(uint8_t *buffer, uint8_t size) NO_INLINE;
-static
-uint8_t serial_recive_packet(uint8_t *buffer, uint8_t size) {
-  uint8_t pecount = 0;
-  for (uint8_t i = 0; i < size; ++i) {
-    uint8_t data;
-    sync_recv();
-    data = serial_read_chunk(&pecount, 8);
-    buffer[i] = data;
-  }
-  return pecount == 0;
-}
-
-inline static
-void change_sender2reciver(void) {
-    sync_send();          //0
-    serial_delay_half1(); //1
-    serial_low();         //2
-    serial_input_with_pullup(); //2
-    serial_delay_half1(); //3
-}
-
-inline static
-void change_reciver2sender(void) {
-    sync_recv();     //0
-    serial_delay();  //1
-    serial_low();    //3
-    serial_output(); //3
-    serial_delay_half1(); //4
-}
-
-static inline uint8_t nibble_bits_count(uint8_t bits)
-{
-    bits = (bits & 0x5) + (bits >> 1 & 0x5);
-    bits = (bits & 0x3) + (bits >> 2 & 0x3);
-    return bits;
-}
-
-// interrupt handle to be used by the target device
-ISR(SERIAL_PIN_INTERRUPT) {
-
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-  serial_low();
-  serial_output();
-  SSTD_t *trans = Transaction_table;
-#else
-  // recive transaction table index
-  uint8_t tid, bits;
-  uint8_t pecount = 0;
-  sync_recv();
-  bits = serial_read_chunk(&pecount,7);
-  tid = bits>>3;
-  bits = (bits&7) != nibble_bits_count(tid);
-  if( bits || pecount> 0 || tid > Transaction_table_size ) {
-      return;
-  }
-  serial_delay_half1();
-
-  serial_high(); // response step1 low->high
-  serial_output();
-  _delay_sub_us(SLAVE_INT_ACK_WIDTH_UNIT*SLAVE_INT_ACK_WIDTH);
-  SSTD_t *trans = &Transaction_table[tid];
-  serial_low(); // response step2 ack high->low
-#endif
-
-  // target send phase
-  if( trans->target2initiator_buffer_size > 0 )
-      serial_send_packet((uint8_t *)trans->target2initiator_buffer,
-                         trans->target2initiator_buffer_size);
-  // target switch to input
-  change_sender2reciver();
-
-  // target recive phase
-  if( trans->initiator2target_buffer_size > 0 ) {
-      if (serial_recive_packet((uint8_t *)trans->initiator2target_buffer,
-                               trans->initiator2target_buffer_size) ) {
-          *trans->status = TRANSACTION_ACCEPTED;
-      } else {
-          *trans->status = TRANSACTION_DATA_ERROR;
-      }
-  } else {
-      *trans->status = TRANSACTION_ACCEPTED;
-  }
-
-  sync_recv(); //weit initiator output to high
-}
-
-/////////
-//  start transaction by initiator
-//
-// int  soft_serial_transaction(int sstd_index)
-//
-// Returns:
-//    TRANSACTION_END
-//    TRANSACTION_NO_RESPONSE
-//    TRANSACTION_DATA_ERROR
-// this code is very time dependent, so we need to disable interrupts
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-int  soft_serial_transaction(void) {
-  SSTD_t *trans = Transaction_table;
-#else
-int  soft_serial_transaction(int sstd_index) {
-  if( sstd_index > Transaction_table_size )
-      return TRANSACTION_TYPE_ERROR;
-  SSTD_t *trans = &Transaction_table[sstd_index];
-#endif
-  cli();
-
-  // signal to the target that we want to start a transaction
-  serial_output();
-  serial_low();
-  _delay_us(SLAVE_INT_WIDTH_US);
-
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-  // wait for the target response
-  serial_input_with_pullup();
-  _delay_us(SLAVE_INT_RESPONSE_TIME);
-
-  // check if the target is present
-  if (serial_read_pin()) {
-    // target failed to pull the line low, assume not present
-    serial_output();
-    serial_high();
-    *trans->status = TRANSACTION_NO_RESPONSE;
-    sei();
-    return TRANSACTION_NO_RESPONSE;
-  }
-
-#else
-  // send transaction table index
-  int tid = (sstd_index<<3) | (7 & nibble_bits_count(sstd_index));
-  sync_send();
-  _delay_sub_us(TID_SEND_ADJUST);
-  serial_write_chunk(tid, 7);
-  serial_delay_half1();
-
-  // wait for the target response (step1 low->high)
-  serial_input_with_pullup();
-  while( !serial_read_pin() ) {
-      _delay_sub_us(2);
-  }
-
-  // check if the target is present (step2 high->low)
-  for( int i = 0; serial_read_pin(); i++ ) {
-      if (i > SLAVE_INT_ACK_WIDTH + 1) {
-          // slave failed to pull the line low, assume not present
-          serial_output();
-          serial_high();
-          *trans->status = TRANSACTION_NO_RESPONSE;
-          sei();
-          return TRANSACTION_NO_RESPONSE;
-      }
-      _delay_sub_us(SLAVE_INT_ACK_WIDTH_UNIT);
-  }
-#endif
-
-  // initiator recive phase
-  // if the target is present syncronize with it
-  if( trans->target2initiator_buffer_size > 0 ) {
-      if (!serial_recive_packet((uint8_t *)trans->target2initiator_buffer,
-                                trans->target2initiator_buffer_size) ) {
-          serial_output();
-          serial_high();
-          *trans->status = TRANSACTION_DATA_ERROR;
-          sei();
-          return TRANSACTION_DATA_ERROR;
-      }
-   }
-
-  // initiator switch to output
-  change_reciver2sender();
-
-  // initiator send phase
-  if( trans->initiator2target_buffer_size > 0 ) {
-      serial_send_packet((uint8_t *)trans->initiator2target_buffer,
-                         trans->initiator2target_buffer_size);
-  }
-
-  // always, release the line when not in use
-  sync_send();
-
-  *trans->status = TRANSACTION_END;
-  sei();
-  return TRANSACTION_END;
-}
-
-#ifdef SERIAL_USE_MULTI_TRANSACTION
-int soft_serial_get_and_clean_status(int sstd_index) {
-    SSTD_t *trans = &Transaction_table[sstd_index];
-    cli();
-    int retval = *trans->status;
-    *trans->status = 0;;
-    sei();
-    return retval;
-}
-#endif
-
-#endif
-
-// Helix serial.c history
-//   2018-1-29 fork from let's split and add PD2, modify sync_recv() (#2308, bceffdefc)
-//   2018-6-28 bug fix master to slave comm and speed up (#3255, 1038bbef4)
-//             (adjusted with avr-gcc 4.9.2)
-//   2018-7-13 remove USE_SERIAL_PD2 macro (#3374, f30d6dd78)
-//             (adjusted with avr-gcc 4.9.2)
-//   2018-8-11 add support multi-type transaction (#3608, feb5e4aae)
-//             (adjusted with avr-gcc 4.9.2)
-//   2018-10-21 fix serial and RGB animation conflict (#4191, 4665e4fff)
-//             (adjusted with avr-gcc 7.3.0)
-//   2018-10-28 re-adjust compiler depend value of delay (#4269, 8517f8a66)
-//             (adjusted with avr-gcc 5.4.0, 7.3.0)
diff --git a/keyboards/crkbd/rev1/legacy/serial.h b/keyboards/crkbd/rev1/legacy/serial.h
deleted file mode 100644
index 7e0c0847a4..0000000000
--- a/keyboards/crkbd/rev1/legacy/serial.h
+++ /dev/null
@@ -1,84 +0,0 @@
-#ifndef SOFT_SERIAL_H
-#define SOFT_SERIAL_H
-
-#include <stdbool.h>
-
-// /////////////////////////////////////////////////////////////////
-// Need Soft Serial defines in config.h
-// /////////////////////////////////////////////////////////////////
-// ex.
-//  #define SOFT_SERIAL_PIN ??   // ?? = D0,D1,D2,D3,E6
-//  OPTIONAL: #define SELECT_SOFT_SERIAL_SPEED ? // ? = 1,2,3,4,5
-//                                               //  1: about 137kbps (default)
-//                                               //  2: about 75kbps
-//                                               //  3: about 39kbps
-//                                               //  4: about 26kbps
-//                                               //  5: about 20kbps
-//
-// //// USE Simple API (OLD API, compatible with let's split serial.c)
-// ex.
-//  #define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
-//  #define SERIAL_MASTER_BUFFER_LENGTH 1
-//
-// //// USE flexible API (using multi-type transaction function)
-//  #define SERIAL_USE_MULTI_TRANSACTION
-//
-// /////////////////////////////////////////////////////////////////
-
-
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-/* --- USE Simple API (OLD API, compatible with let's split serial.c) */
-#if SERIAL_SLAVE_BUFFER_LENGTH > 0
-extern volatile uint8_t serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH];
-#endif
-#if SERIAL_MASTER_BUFFER_LENGTH > 0
-extern volatile uint8_t serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH];
-#endif
-
-void serial_master_init(void);
-void serial_slave_init(void);
-int serial_update_buffers(void);
-
-#endif // USE Simple API
-
-// Soft Serial Transaction Descriptor
-typedef struct _SSTD_t  {
-    uint8_t *status;
-    uint8_t initiator2target_buffer_size;
-    uint8_t *initiator2target_buffer;
-    uint8_t target2initiator_buffer_size;
-    uint8_t *target2initiator_buffer;
-} SSTD_t;
-#define TID_LIMIT( table ) (sizeof(table) / sizeof(SSTD_t))
-
-// initiator is transaction start side
-void soft_serial_initiator_init(SSTD_t *sstd_table, int sstd_table_size);
-// target is interrupt accept side
-void soft_serial_target_init(SSTD_t *sstd_table, int sstd_table_size);
-
-// initiator resullt
-#define TRANSACTION_END 0
-#define TRANSACTION_NO_RESPONSE 0x1
-#define TRANSACTION_DATA_ERROR  0x2
-#define TRANSACTION_TYPE_ERROR  0x4
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-int  soft_serial_transaction(void);
-#else
-int  soft_serial_transaction(int sstd_index);
-#endif
-
-// target status
-// *SSTD_t.status has
-//   initiator:
-//       TRANSACTION_END
-//    or TRANSACTION_NO_RESPONSE
-//    or TRANSACTION_DATA_ERROR
-//   target:
-//       TRANSACTION_DATA_ERROR
-//    or TRANSACTION_ACCEPTED
-#define TRANSACTION_ACCEPTED 0x8
-#ifdef SERIAL_USE_MULTI_TRANSACTION
-int  soft_serial_get_and_clean_status(int sstd_index);
-#endif
-
-#endif /* SOFT_SERIAL_H */
diff --git a/keyboards/crkbd/rev1/legacy/serial_config.h b/keyboards/crkbd/rev1/legacy/serial_config.h
deleted file mode 100644
index 40d11d4de2..0000000000
--- a/keyboards/crkbd/rev1/legacy/serial_config.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef SOFT_SERIAL_PIN
-#define SOFT_SERIAL_PIN D2
-#define SERIAL_USE_MULTI_TRANSACTION
-#endif
diff --git a/keyboards/crkbd/rev1/legacy/serial_config_simpleapi.h b/keyboards/crkbd/rev1/legacy/serial_config_simpleapi.h
deleted file mode 100644
index bd152ddda3..0000000000
--- a/keyboards/crkbd/rev1/legacy/serial_config_simpleapi.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#pragma once
-
-#undef SERIAL_USE_MULTI_TRANSACTION
-#define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
-#define SERIAL_MASTER_BUFFER_LENGTH MATRIX_ROWS/2
diff --git a/keyboards/crkbd/rev1/legacy/split_scomm.c b/keyboards/crkbd/rev1/legacy/split_scomm.c
deleted file mode 100644
index eccf2f3d2f..0000000000
--- a/keyboards/crkbd/rev1/legacy/split_scomm.c
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifdef USE_SERIAL
-#ifdef SERIAL_USE_MULTI_TRANSACTION
-/* --- USE flexible API (using multi-type transaction function) --- */
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <stddef.h>
-#include "split_scomm.h"
-#include "serial.h"
-#ifdef CONSOLE_ENABLE
-  #include "debug.h"
-#endif
-
-uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
-uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
-uint8_t volatile status_com = 0;
-uint8_t volatile status1 = 0;
-uint8_t slave_buffer_change_count = 0;
-uint8_t s_change_old = 0xff;
-uint8_t s_change_new = 0xff;
-
-SSTD_t transactions[] = {
-#define GET_SLAVE_STATUS 0
-    /* master buffer not changed, only recive slave_buffer_change_count */
-    { (uint8_t *)&status_com,
-      0, NULL,
-      sizeof(slave_buffer_change_count), &slave_buffer_change_count,
-    },
-#define PUT_MASTER_GET_SLAVE_STATUS 1
-    /* master buffer changed need send, and recive slave_buffer_change_count  */
-    { (uint8_t *)&status_com,
-      sizeof(serial_master_buffer), (uint8_t *)serial_master_buffer,
-      sizeof(slave_buffer_change_count), &slave_buffer_change_count,
-    },
-#define GET_SLAVE_BUFFER 2
-    /* recive serial_slave_buffer */
-    { (uint8_t *)&status1,
-      0, NULL,
-      sizeof(serial_slave_buffer), (uint8_t *)serial_slave_buffer
-    }
-};
-
-void serial_master_init(void)
-{
-    soft_serial_initiator_init(transactions, TID_LIMIT(transactions));
-}
-
-void serial_slave_init(void)
-{
-    soft_serial_target_init(transactions, TID_LIMIT(transactions));
-}
-
-// 0 => no error
-// 1 => slave did not respond
-// 2 => checksum error
-int serial_update_buffers(int master_update)
-{
-    int status, smatstatus;
-    static int need_retry = 0;
-
-    if( s_change_old != s_change_new ) {
-        smatstatus = soft_serial_transaction(GET_SLAVE_BUFFER);
-        if( smatstatus == TRANSACTION_END ) {
-            s_change_old = s_change_new;
-#ifdef CONSOLE_ENABLE
-            if (debug_matrix) {
-                uprintf("slave matrix = %b %b %b %b\n",
-                    serial_slave_buffer[0], serial_slave_buffer[1],
-                    serial_slave_buffer[2], serial_slave_buffer[3]);
-            }
-#endif
-        }
-    } else {
-        // serial_slave_buffer dosen't change
-        smatstatus = TRANSACTION_END; // dummy status
-    }
-
-    if( !master_update && !need_retry) {
-        status = soft_serial_transaction(GET_SLAVE_STATUS);
-    } else {
-        status = soft_serial_transaction(PUT_MASTER_GET_SLAVE_STATUS);
-    }
-    if( status == TRANSACTION_END ) {
-        s_change_new = slave_buffer_change_count;
-        need_retry = 0;
-    } else {
-        need_retry = 1;
-    }
-    return smatstatus;
-}
-
-#endif // SERIAL_USE_MULTI_TRANSACTION
-#endif /* USE_SERIAL */
diff --git a/keyboards/crkbd/rev1/legacy/split_scomm.h b/keyboards/crkbd/rev1/legacy/split_scomm.h
deleted file mode 100644
index 47f0ca1b9d..0000000000
--- a/keyboards/crkbd/rev1/legacy/split_scomm.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef SPLIT_COMM_H
-#define SPLIT_COMM_H
-
-#ifndef SERIAL_USE_MULTI_TRANSACTION
-/* --- USE Simple API (OLD API, compatible with let's split serial.c) --- */
-#include "serial.h"
-
-#else
-/* --- USE flexible API (using multi-type transaction function) --- */
-// Buffers for master - slave communication
-#define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
-#define SERIAL_MASTER_BUFFER_LENGTH MATRIX_ROWS/2
-
-extern volatile uint8_t serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH];
-extern volatile uint8_t serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH];
-extern uint8_t slave_buffer_change_count;
-
-void serial_master_init(void);
-void serial_slave_init(void);
-int serial_update_buffers(int master_changed);
-
-#endif
-
-#endif /* SPLIT_COMM_H */
diff --git a/keyboards/crkbd/rev1/legacy/split_util.c b/keyboards/crkbd/rev1/legacy/split_util.c
deleted file mode 100644
index d0fee04ad6..0000000000
--- a/keyboards/crkbd/rev1/legacy/split_util.c
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include <avr/io.h>
-#include <avr/wdt.h>
-#include <avr/power.h>
-#include <avr/interrupt.h>
-#include <util/delay.h>
-#include <avr/eeprom.h>
-#include "split_util.h"
-#include "matrix.h"
-#include "keyboard.h"
-#include "wait.h"
-
-#ifdef EE_HANDS
-#    include "eeconfig.h"
-#endif
-
-#ifdef USE_MATRIX_I2C
-#  include "i2c_master.h"
-#else
-#  include "split_scomm.h"
-#endif
-
-#ifndef SPLIT_USB_TIMEOUT
-#    define SPLIT_USB_TIMEOUT 2000
-#endif
-
-#ifndef SPLIT_USB_TIMEOUT_POLL
-#    define SPLIT_USB_TIMEOUT_POLL 10
-#endif
-
-volatile bool isLeftHand = true;
-
-bool waitForUsb(void) {
-    for (uint8_t i = 0; i < (SPLIT_USB_TIMEOUT / SPLIT_USB_TIMEOUT_POLL); i++) {
-        // This will return true if a USB connection has been established
-        if (UDADDR & _BV(ADDEN)) {
-            return true;
-        }
-        wait_ms(SPLIT_USB_TIMEOUT_POLL);
-    }
-
-    // Avoid NO_USB_STARTUP_CHECK - Disable USB as the previous checks seem to enable it somehow
-    (USBCON &= ~(_BV(USBE) | _BV(OTGPADE)));
-
-    return false;
-}
-
-__attribute__((weak)) bool is_keyboard_left(void) {
-#if defined(SPLIT_HAND_PIN)
-    // Test pin SPLIT_HAND_PIN for High/Low, if low it's right hand
-    setPinInput(SPLIT_HAND_PIN);
-    return readPin(SPLIT_HAND_PIN);
-#elif defined(EE_HANDS)
-    return eeconfig_read_handedness();
-#elif defined(MASTER_RIGHT)
-    return !has_usb();
-#endif
-
-    return has_usb();
-}
-
-__attribute__((weak)) bool has_usb(void) {
-    static enum { UNKNOWN, MASTER, SLAVE } usbstate = UNKNOWN;
-
-    // only check once, as this is called often
-    if (usbstate == UNKNOWN) {
-#if defined(SPLIT_USB_DETECT)
-        usbstate = waitForUsb() ? MASTER : SLAVE;
-#elif defined(__AVR__)
-        USBCON |= (1 << OTGPADE);  // enables VBUS pad
-        wait_us(5);
-
-        usbstate = (USBSTA & (1 << VBUS)) ? MASTER : SLAVE;  // checks state of VBUS
-#else
-        usbstate = MASTER;
-#endif
-    }
-
-    return (usbstate == MASTER);
-}
-
-static void keyboard_master_setup(void) {
-
-#ifdef USE_MATRIX_I2C
-    i2c_init();
-#else
-    serial_master_init();
-#endif
-}
-
-static void keyboard_slave_setup(void) {
-
-#ifdef USE_MATRIX_I2C
-    i2c_slave_init(SLAVE_I2C_ADDRESS);
-#else
-    serial_slave_init();
-#endif
-}
-
-// this code runs before the usb and keyboard is initialized
-void split_keyboard_setup(void) {
-    isLeftHand = is_keyboard_left();
-
-   if (has_usb()) {
-      keyboard_master_setup();
-   } else {
-      keyboard_slave_setup();
-   }
-   sei();
-}
diff --git a/keyboards/crkbd/rev1/legacy/split_util.h b/keyboards/crkbd/rev1/legacy/split_util.h
deleted file mode 100644
index b2ddc1f97a..0000000000
--- a/keyboards/crkbd/rev1/legacy/split_util.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
-Copyright 2019 @foostan
-Copyright 2020 Drashna Jaelre <@drashna>
-
-This program is free software: you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#ifndef SPLIT_KEYBOARD_UTIL_H
-#define SPLIT_KEYBOARD_UTIL_H
-
-#include <stdbool.h>
-#include "eeconfig.h"
-
-#define SLAVE_I2C_ADDRESS           0x32
-
-extern volatile bool isLeftHand;
-
-// slave version of matix scan, defined in matrix.c
-uint8_t matrix_slave_scan(void);
-
-void split_keyboard_setup(void);
-bool has_usb(void);
-
-void matrix_master_OLED_init (void);
-
-#endif
diff --git a/keyboards/crkbd/rev1/legacy/ssd1306.c b/keyboards/crkbd/rev1/legacy/ssd1306.c
deleted file mode 100644
index b04b7e15c1..0000000000
--- a/keyboards/crkbd/rev1/legacy/ssd1306.c
+++ /dev/null
@@ -1,357 +0,0 @@
-#ifdef SSD1306OLED
-
-#include "ssd1306.h"
-#include "i2c.h"
-#include <string.h>
-#include "print.h"
-#ifdef PROTOCOL_LUFA
-#include "lufa.h"
-#endif
-#include "sendchar.h"
-#include "timer.h"
-
-struct CharacterMatrix display;
-
-extern const unsigned char font[] PROGMEM;
-
-#ifndef OLED_BLANK_CHAR
-#define OLED_BLANK_CHAR ' '
-#endif
-
-#ifndef OLED_BITS_FILTER
-#define OLED_BITS_FILTER
-#endif
-
-// Set this to 1 to help diagnose early startup problems
-// when testing power-on with ble.  Turn it off otherwise,
-// as the latency of printing most of the debug info messes
-// with the matrix scan, causing keys to drop.
-#define DEBUG_TO_SCREEN 0
-
-//static uint16_t last_battery_update;
-//static uint32_t vbat;
-//#define BatteryUpdateInterval 10000 /* milliseconds */
-
-// 'last_flush' is declared as uint16_t,
-// so this must be less than 65535
-#ifndef ScreenOffInterval
-#define ScreenOffInterval 60000 /* milliseconds */
-#endif
-
-#if DEBUG_TO_SCREEN
-static uint8_t displaying;
-#endif
-static uint16_t last_flush;
-
-static bool force_dirty = true;
-
-// Write command sequence.
-// Returns true on success.
-static inline bool _send_cmd1(uint8_t cmd) {
-  bool res = false;
-
-  if (i2c_start_write(SSD1306_ADDRESS)) {
-    xprintf("failed to start write to %d\n", SSD1306_ADDRESS);
-    goto done;
-  }
-
-  if (i2c_master_write(0x0 /* command byte follows */)) {
-    print("failed to write control byte\n");
-
-    goto done;
-  }
-
-  if (i2c_master_write(cmd)) {
-    xprintf("failed to write command %d\n", cmd);
-    goto done;
-  }
-  res = true;
-done:
-  i2c_master_stop();
-  return res;
-}
-
-#define send_cmd1(c) if (!_send_cmd1(c)) {goto done;}
-#define send_cmds(c) if (!_send_cmds(c,sizeof(c))) {goto done;}
-#define cmd1(X) X
-#define cmd2(X,Y) X,Y
-#define cmd3(X,Y,Z) X,Y,Z
-
-static bool _send_cmds(const uint8_t* p,uint8_t sz) {
-  for(uint8_t i=sz;i;i--) {
-    send_cmd1( pgm_read_byte(p++) );
-  }
-  return true;
-done:
-  return false;
-}
-
-#define SEND_CMDS(...) {static const uint8_t _cmds[] PROGMEM = { __VA_ARGS__,0 };send_cmds(_cmds);}
-
-static void clear_display(void) {
-  matrix_clear(&display);
-
-  // Clear all of the display bits (there can be random noise
-  // in the RAM on startup)
-  SEND_CMDS(
-    cmd3(PageAddr, 0, (DisplayHeight / 8) - 1),
-    cmd3(ColumnAddr, 0, DisplayWidth - 1)
-  );
-
-  if (i2c_start_write(SSD1306_ADDRESS)) {
-    goto done;
-  }
-  if (i2c_master_write(0x40)) {
-    // Data mode
-    goto done;
-  }
-  for (uint8_t row = MatrixRows;row; row--) {
-    for (uint8_t col = DisplayWidth; col; col--) {
-      i2c_master_write(0);
-    }
-  }
-
-  display.dirty = false;
-
-done:
-  i2c_master_stop();
-}
-
-#if DEBUG_TO_SCREEN
-#undef sendchar
-static int8_t capture_sendchar(uint8_t c) {
-  sendchar(c);
-  iota_gfx_write_char(c);
-
-  if (!displaying) {
-    iota_gfx_flush();
-  }
-  return 0;
-}
-#endif
-
-bool iota_gfx_init(bool rotate) {
-  bool success = false;
-
-  i2c_master_init();
-  SEND_CMDS(
-    cmd1(DisplayOff),
-    cmd2(SetDisplayClockDiv, 0x80),
-    cmd2(SetMultiPlex, DisplayHeight - 1),
-    cmd2(SetDisplayOffset, 0),
-    cmd1(SetStartLine | 0x0),
-    cmd2(SetChargePump, 0x14 /* Enable */),
-    cmd2(SetMemoryMode, 0 /* horizontal addressing */)
-  );
-
-  if(rotate){
-    // the following Flip the display orientation 180 degrees
-  SEND_CMDS(
-    cmd1(SegRemap),
-    cmd1(ComScanInc)
-  );
-  }else{
-    // Flips the display orientation 0 degrees
-  SEND_CMDS(
-      cmd1(SegRemap | 0x1),
-      cmd1(ComScanDec)
-    );
-  }
-
-  SEND_CMDS(
-#ifdef SSD1306_128X64
-	cmd2(SetComPins, 0x12),
-#else
-	cmd2(SetComPins, 0x2),
-#endif
-    cmd2(SetContrast, 0x8f),
-    cmd2(SetPreCharge, 0xf1),
-    cmd2(SetVComDetect, 0x40),
-    cmd1(DisplayAllOnResume),
-    cmd1(NormalDisplay),
-    cmd1(DeActivateScroll),
-    cmd1(DisplayOn),
-
-    cmd2(SetContrast, 0) // Dim
-  );
-
-  clear_display();
-
-  success = true;
-
-  iota_gfx_flush();
-
-#if DEBUG_TO_SCREEN
-  print_set_sendchar(capture_sendchar);
-#endif
-
-done:
-  return success;
-}
-
-bool iota_gfx_off(void) {
-  bool success = false;
-
-  send_cmd1(DisplayOff);
-  success = true;
-
-done:
-  return success;
-}
-
-bool iota_gfx_on(void) {
-  bool success = false;
-
-  send_cmd1(DisplayOn);
-  success = true;
-
-done:
-  return success;
-}
-
-void matrix_write_char_inner(struct CharacterMatrix *matrix, uint8_t c) {
-  *matrix->cursor = c;
-  ++matrix->cursor;
-
-  if (matrix->cursor - &matrix->display[0][0] == sizeof(matrix->display)) {
-    // We went off the end; scroll the display upwards by one line
-    memmove(&matrix->display[0], &matrix->display[1],
-            MatrixCols * (MatrixRows - 1));
-    matrix->cursor = &matrix->display[MatrixRows - 1][0];
-    memset(matrix->cursor, OLED_BLANK_CHAR, MatrixCols);
-  }
-}
-
-void matrix_write_char(struct CharacterMatrix *matrix, uint8_t c) {
-  matrix->dirty = true;
-
-  if (c == '\n') {
-    // Clear to end of line from the cursor and then move to the
-    // start of the next line
-    uint8_t cursor_col = (matrix->cursor - &matrix->display[0][0]) % MatrixCols;
-
-    while (cursor_col++ < MatrixCols) {
-      matrix_write_char_inner(matrix, OLED_BLANK_CHAR);
-    }
-    return;
-  }
-
-  matrix_write_char_inner(matrix, c);
-}
-
-void iota_gfx_write_char(uint8_t c) {
-  matrix_write_char(&display, c);
-}
-
-void matrix_write(struct CharacterMatrix *matrix, const char *data) {
-  while (*data) {
-    matrix_write_char(matrix, *data);
-    ++data;
-  }
-}
-
-void matrix_write_ln(struct CharacterMatrix *matrix, const char *data) {
-  matrix_write(matrix, data);
-  matrix_write(matrix, "\n");
-}
-
-void iota_gfx_write(const char *data) {
-  matrix_write(&display, data);
-}
-
-void matrix_write_P(struct CharacterMatrix *matrix, const char *data) {
-  while (true) {
-    uint8_t c = pgm_read_byte(data);
-    if (c == 0) {
-      return;
-    }
-    matrix_write_char(matrix, c);
-    ++data;
-  }
-}
-
-void iota_gfx_write_P(const char *data) {
-  matrix_write_P(&display, data);
-}
-
-void matrix_clear(struct CharacterMatrix *matrix) {
-  memset(matrix->display, OLED_BLANK_CHAR, sizeof(matrix->display));
-  matrix->cursor = &matrix->display[0][0];
-  matrix->dirty = true;
-}
-
-void iota_gfx_clear_screen(void) {
-  matrix_clear(&display);
-}
-
-void matrix_render(struct CharacterMatrix *matrix) {
-  last_flush = timer_read();
-  iota_gfx_on();
-#if DEBUG_TO_SCREEN
-  ++displaying;
-#endif
-
-  // Move to the home position
-  SEND_CMDS(
-    cmd3(PageAddr, 0, MatrixRows - 1),
-    cmd3(ColumnAddr, 0, (MatrixCols * FontWidth) - 1)
-  );
-
-  if (i2c_start_write(SSD1306_ADDRESS)) {
-    goto done;
-  }
-  if (i2c_master_write(0x40)) {
-    // Data mode
-    goto done;
-  }
-
-  for (uint8_t row = 0; row < MatrixRows; ++row) {
-    for (uint8_t col = 0; col < MatrixCols; ++col) {
-      const uint8_t *glyph = font + (matrix->display[row][col] * FontWidth);
-
-      for (uint8_t glyphCol = 0; glyphCol < FontWidth; ++glyphCol) {
-        uint8_t colBits = pgm_read_byte(glyph + glyphCol);
-        i2c_master_write(colBits OLED_BITS_FILTER);
-      }
-
-      // 1 column of space between chars (it's not included in the glyph)
-      //i2c_master_write(0);
-    }
-  }
-
-  matrix->dirty = false;
-
-done:
-  i2c_master_stop();
-#if DEBUG_TO_SCREEN
-  --displaying;
-#endif
-}
-
-void iota_gfx_flush(void) {
-  matrix_render(&display);
-}
-
-__attribute__ ((weak))
-void iota_gfx_task_user(void) {
-}
-
-void iota_gfx_task(void) {
-  iota_gfx_task_user();
-
-  if (display.dirty|| force_dirty) {
-    iota_gfx_flush();
-    force_dirty = false;
-  }
-
-  if (ScreenOffInterval !=0 && timer_elapsed(last_flush) > ScreenOffInterval) {
-    iota_gfx_off();
-  }
-}
-
-bool process_record_gfx(uint16_t keycode, keyrecord_t *record) {
-  force_dirty = true;
-  return true;
-}
-
-#endif
diff --git a/keyboards/crkbd/rev1/legacy/ssd1306.h b/keyboards/crkbd/rev1/legacy/ssd1306.h
deleted file mode 100644
index 11a3cc67f4..0000000000
--- a/keyboards/crkbd/rev1/legacy/ssd1306.h
+++ /dev/null
@@ -1,90 +0,0 @@
-#pragma once
-
-#include <stdbool.h>
-#include <stdio.h>
-#include "action.h"
-
-enum ssd1306_cmds {
-  DisplayOff = 0xAE,
-  DisplayOn = 0xAF,
-
-  SetContrast = 0x81,
-  DisplayAllOnResume = 0xA4,
-
-  DisplayAllOn = 0xA5,
-  NormalDisplay = 0xA6,
-  InvertDisplay = 0xA7,
-  SetDisplayOffset = 0xD3,
-  SetComPins = 0xda,
-  SetVComDetect = 0xdb,
-  SetDisplayClockDiv = 0xD5,
-  SetPreCharge = 0xd9,
-  SetMultiPlex = 0xa8,
-  SetLowColumn = 0x00,
-  SetHighColumn = 0x10,
-  SetStartLine = 0x40,
-
-  SetMemoryMode = 0x20,
-  ColumnAddr = 0x21,
-  PageAddr = 0x22,
-
-  ComScanInc = 0xc0,
-  ComScanDec = 0xc8,
-  SegRemap = 0xa0,
-  SetChargePump = 0x8d,
-  ExternalVcc = 0x01,
-  SwitchCapVcc = 0x02,
-
-  ActivateScroll = 0x2f,
-  DeActivateScroll = 0x2e,
-  SetVerticalScrollArea = 0xa3,
-  RightHorizontalScroll = 0x26,
-  LeftHorizontalScroll = 0x27,
-  VerticalAndRightHorizontalScroll = 0x29,
-  VerticalAndLeftHorizontalScroll = 0x2a,
-};
-
-// Controls the SSD1306 128x32 OLED display via i2c
-
-#ifndef SSD1306_ADDRESS
-#define SSD1306_ADDRESS 0x3C
-#endif
-
-#define DisplayHeight 32
-#define DisplayWidth 128
-
-#define FontHeight 8
-#define FontWidth 6
-
-#define MatrixRows (DisplayHeight / FontHeight)
-#define MatrixCols (DisplayWidth / FontWidth)
-
-struct CharacterMatrix {
-  uint8_t display[MatrixRows][MatrixCols];
-  uint8_t *cursor;
-  bool dirty;
-};
-
-extern struct CharacterMatrix display;
-
-bool iota_gfx_init(bool rotate);
-void iota_gfx_task(void);
-bool iota_gfx_off(void);
-bool iota_gfx_on(void);
-void iota_gfx_flush(void);
-void iota_gfx_write_char(uint8_t c);
-void iota_gfx_write(const char *data);
-void iota_gfx_write_P(const char *data);
-void iota_gfx_clear_screen(void);
-
-void iota_gfx_task_user(void);
-
-void matrix_clear(struct CharacterMatrix *matrix);
-void matrix_write_char_inner(struct CharacterMatrix *matrix, uint8_t c);
-void matrix_write_char(struct CharacterMatrix *matrix, uint8_t c);
-void matrix_write(struct CharacterMatrix *matrix, const char *data);
-void matrix_write_ln(struct CharacterMatrix *matrix, const char *data);
-void matrix_write_P(struct CharacterMatrix *matrix, const char *data);
-void matrix_render(struct CharacterMatrix *matrix);
-
-bool process_record_gfx(uint16_t keycode, keyrecord_t *record);