Update readme.md

I fixed the picture of the layout and added a bit of an explanation. It now matches the readme file from the uppercase BASE folder

common_features.mk

@@ -54,6 +54,12 @@ ifeq ($(strip $(COMBO_ENABLE)), yes)
     SRC += $(QUANTUM_DIR)/process_keycode/process_combo.c
 endif
 
+ifeq ($(strip $(STENO_ENABLE)), yes)
+    OPT_DEFS += -DSTENO_ENABLE
+	VIRTSER_ENABLE := yes
+	SRC += $(QUANTUM_DIR)/process_keycode/process_steno.c
+endif
+
 ifeq ($(strip $(VIRTSER_ENABLE)), yes)
     OPT_DEFS += -DVIRTSER_ENABLE
 endif

docs/_summary.md

@@ -1,4 +1,4 @@
-* [Getting started](README.md) 
+* [Getting started](README.md)
   * [QMK Overview](qmk_overview.md)
   * [Build Environment Setup](build_environment_setup.md)
     * [Vagrant Guide](vagrant_guide.md)
@@ -16,6 +16,7 @@
   * [Tap Dance](tap_dance.md)
   * [Mouse keys](mouse_keys.md)
   * [Unicode](unicode.md)
+  * [Stenography](stenography.md)
 
 * Reference
   * [Glossary](glossary.md)
@@ -27,7 +28,7 @@
   * [Customizing Functionality](custom_quantum_functions.md)
   * [Documentation Best Practices](documentation_best_practices.md)
   * [Unit Testing](unit_testing.md)
-  
+
 * For Makers and Modders
   * [Adding a keyboard to QMK](adding_a_keyboard_to_qmk.md)
   * [Adding features to QMK](adding_features_to_qmk.md)
@@ -39,7 +40,7 @@
 * For a Deeper Understanding
   * [How Keyboards Work](basic_how_keyboards_work.md)
   * [Understanding QMK](understanding_qmk.md)
-  
+
 * Other Topics
   * [General FAQ](faq.md)
   * [Using Eclipse with QMK](eclipse.md)

docs/porting_your_keyboard_to_qmk.md

@@ -20,7 +20,7 @@ For the `DIODE_DIRECTION`, most hand-wiring guides will instruct you to wire the
 
 `BACKLIGHT_LEVELS` is how many levels exist for your backlight - max is 15, and they are computed automatically from this number.
 
-## `/keyboards/<keyboard>/Makefile`
+## `/keyboards/<keyboard>/rules.mk`
 
 The values at the top likely won't need to be changed, since most boards use the `atmega32u4` chip. The `BOOTLOADER_SIZE` will need to be adjusted based on your MCU type. It's defaulted to the Teensy, since that's the most common controller. Below is quoted from the `Makefile`.
 

docs/stenography.md

@@ -0,0 +1,108 @@
+# Stenography in QMK
+
+[Stenography](https://en.wikipedia.org/wiki/Stenotype) is a method of writing most often used by court reports, closed-captioning, and real-time transcription for the deaf. In stenography words are chorded syllable by syllable with a mixture of spelling, phonetic, and shortcut (briefs) strokes. Professional stenographers can reach 200-300 WPM without any of the strain usually found in standard typing and with far fewer errors (>99.9% accuracy).
+
+The [Open Steno Project](http://www.openstenoproject.org/) has built an open-source program called Plover that provides real-time translation of steno strokes into words and commands. It has an established dictionary and supports
+
+## Plover with QWERTY Keyboard
+
+Plover can work with any standard QWERTY keyboard, although it is more efficient if the keyboard supports NKRO (n-key rollover) to allow Plover to see all the pressed keys at once. An example keymap for Plover can be found in `planck/keymaps/default`. Switching to the `PLOVER` layer adjusts the position of the keyboard to support the number bar.
+
+To use Plover with QMK just enable NKRO and optionally adjust your layout if you have anything other than a standard layout. You may also want to purchase some steno-friendly keycaps to make it easier to hit multiple keys.
+
+## Plover with Steno Protocol
+
+Plover also understands the language of several steno machines. QMK can speak a couple of these languages, TX Bolt and GeminiRP. An example layout can be found in `planck/keymaps/steno`.
+
+When QMK speaks to Plover over a steno protocol Plover will not use the keyboard as input. This means that you can switch back and forth between a standard keyboard and your steno keyboard, or even switch layers from Plover to standard and back without needing to activate/deactive Plover.
+
+In this mode Plover expects to speak with a steno machine over a serial port so QMK will present itself to the operating system as a virtual serial port in addition to a keyboard. By default QMK will speak the TX Bolt protocol but can be switched to GeminiRP; the last protocol used is stored in non-volatile memory so QMK will use the same protocol on restart.
+
+> Note: Due to hardware limitations you may not be able to run both a virtual serial port and mouse emulation at the same time.
+
+### TX Bolt
+
+TX Bolt communicates the status of 24 keys over a very simple protocol in variable-sized (1-5 byte) packets.
+
+### GeminiRP
+
+GeminiRP encodes 42 keys into a 6-byte packet. While TX Bolt contains everything that is necessary for standard stenography, GeminiRP opens up many more options, including supporting non-English theories.
+
+## Configuring QMK for Steno
+
+Firstly, enable steno in your keymap's Makefile. You should also diable mousekeys to prevent conflicts.
+
+```Makefile
+STENO_ENABLE = yes
+MOUSEKEY_ENABLE = no
+```
+
+In your keymap create a new layer for Plover. You will need to include `keymap_steno.h`. See `planck/keymaps/steno/keymap.c` for an example. Remember to create a key to switch to the layer as well as a key for exiting the layer. If you would like to switch modes on the fly you can use the keycodes `QK_STENO_BOLT` and `QK_STENO_GEMINI`. If you only want to use one of the protocols you may set it up in your initialization function:
+
+```C
+void matrix_init_user() {
+  steno_set_mode(STENO_MODE_GEMINI); // or STENO_MODE_BOLT
+}
+```
+
+Once you have your keyboard flashed launch Plover. Click the 'Configure...' button. In the 'Machine' tab select the Stenotype Machine that corresponds to your desired protocol. Click the 'Configure...' button on this tab and enter the serial port or click 'Scan'. Baud rate is fine at 9600 (although you should be able to set as high as 115200 with no issues). Use the default settings for everything else (Data Bits: 8, Stop Bits: 1, Parity: N, no flow control).
+
+On the display tab click 'Open stroke display'. With Plover disabled you should be able to hit keys on your keyboard and see them show up in the stroke display window. Use this to make sure you have set up your keymap correctly. You are now ready to steno!
+
+## Learning Stenography
+
+* [Learn Plover!](https://sites.google.com/site/ploverdoc/)
+* [QWERTY Steno](http://qwertysteno.com/Home/)
+* [Steno Jig](https://joshuagrams.github.io/steno-jig/)
+* More resources at the Plover [Learning Stenography](https://github.com/openstenoproject/plover/wiki/Learning-Stenography) wiki
+
+## Keycode Reference
+
+As defined in `keymap_steno.h`.
+
+> Note: TX Bolt does not support the full set of keys. The TX Bolt implementation in QMK will map the GeminiRP keys to the nearest TX Bolt key so that one key map will work for both.
+
+|GeminiRP|TX Bolt|Steno Key|
+|--------|-------|-----------|
+|`STN_N1`|`STN_NUM`|Number bar #1|
+|`STN_N2`|`STN_NUM`|Number bar #2|
+|`STN_N3`|`STN_NUM`|Number bar #3|
+|`STN_N4`|`STN_NUM`|Number bar #4|
+|`STN_N5`|`STN_NUM`|Number bar #5|
+|`STN_N6`|`STN_NUM`|Number bar #6|
+|`STN_N7`|`STN_NUM`|Number bar #7|
+|`STN_N8`|`STN_NUM`|Number bar #8|
+|`STN_N9`|`STN_NUM`|Number bar #9|
+|`STN_NA`|`STN_NUM`|Number bar #A|
+|`STN_NB`|`STN_NUM`|Number bar #B|
+|`STN_NC`|`STN_NUM`|Number bar #C|
+|`STN_S1`|`STN_SL`| `S-` upper|
+|`STN_S2`|`STN_SL`| `S-` lower|
+|`STN_TL`|`STN_TL`| `T-`|
+|`STN_KL`|`STN_KL`| `K-`|
+|`STN_PL`|`STN_PL`| `P-`|
+|`STN_WL`|`STN_WL`| `W-`|
+|`STN_HL`|`STN_HL`| `H-`|
+|`STN_RL`|`STN_RL`| `R-`|
+|`STN_A`|`STN_A`| `A` vowel|
+|`STN_O`|`STN_O`| `O` vowel|
+|`STN_ST1`|`STN_STR`| `*` upper-left |
+|`STN_ST2`|`STN_STR`| `*` lower-left|
+|`STN_ST3`|`STN_STR`| `*` upper-right|
+|`STN_ST4`|`STN_STR`| `*` lower-right|
+|`STN_E`|`STN_E`| `E` vowel|
+|`STN_U`|`STN_U`| `U` vowel|
+|`STN_FR`|`STN_FR`| `-F`|
+|`STN_PR`|`STN_PR`| `-P`|
+|`STN_RR`|`STN_RR`| `-R`|
+|`STN_BR`|`STN_BR`| `-B`|
+|`STN_LR`|`STN_LR`| `-L`|
+|`STN_GR`|`STN_GR`| `-G`|
+|`STN_TR`|`STN_TR`| `-T`|
+|`STN_SR`|`STN_SR`| `-S`|
+|`STN_DR`|`STN_DR`| `-D`|
+|`STN_ZR`|`STN_ZR`| `-Z`|
+|`STN_FN`|| (GeminiRP only)|
+|`STN_RES1`||(GeminiRP only)|
+|`STN_RES2`||(GeminiRP only)|
+|`STN_PWR`||(GeminiRP only)|

keyboards/deltasplit75/Makefile

@@ -0,0 +1,5 @@
+SUBPROJECT_DEFAULT = v2
+
+ifndef MAKEFILE_INCLUDED
+	include ../../Makefile
+endif

keyboards/deltasplit75/config.h

@@ -0,0 +1,29 @@
+/*
+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/>.
+*/
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include "config_common.h"
+
+#ifdef SUBPROJECT_protosplit
+    #include "protosplit/config.h"
+#endif
+#ifdef SUBPROJECT_v2
+    #include "v2/config.h"
+#endif
+#endif

keyboards/deltasplit75/deltasplit75.c

@@ -0,0 +1 @@
+#include "deltasplit75.h"

keyboards/deltasplit75/deltasplit75.h

@@ -0,0 +1,13 @@
+#ifndef DELTASPLIT75_H
+#define DELTASPLIT75_H
+
+#ifdef SUBPROJECT_v2
+    #include "v2.h"
+#endif
+#ifdef SUBPROJECT_protosplit
+    #include "protosplit.h"
+#endif
+
+#include "quantum.h"
+
+#endif

keyboards/deltasplit75/eeprom-lefthand.eep

@@ -0,0 +1,2 @@
+:0B0000000000000000000000000001F4
+:00000001FF

keyboards/deltasplit75/eeprom-righthand.eep

@@ -0,0 +1,2 @@
+:0B0000000000000000000000000000F5
+:00000001FF

keyboards/deltasplit75/i2c.c

@@ -0,0 +1,162 @@
+#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"
+
+#ifdef USE_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
+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

keyboards/deltasplit75/i2c.h

@@ -0,0 +1,31 @@
+#ifndef I2C_H
+#define I2C_H
+
+#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
+#define SCL_CLOCK  100000L
+
+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);
+
+#endif

keyboards/deltasplit75/keymaps/default/config.h

@@ -0,0 +1,31 @@
+/*
+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/>.
+*/
+
+
+#define USE_SERIAL
+
+#define MASTER_LEFT
+// #define _MASTER_RIGHT
+// #define EE_HANDS
+
+
+#ifdef SUBPROJECT_v2
+    #include "../../v2/config.h"
+#endif
+#ifdef SUBPROJECT_protosplit
+    #include "../../protosplit/config.h"
+#endif

keyboards/deltasplit75/keymaps/default/keymap.c

@@ -0,0 +1,31 @@
+#include "deltasplit75.h"
+#include "action_layer.h"
+#include "eeconfig.h"
+
+extern keymap_config_t keymap_config;
+
+// Each layer gets a name for readability, which is then used in the keymap matrix below.
+// The underscores don't mean anything - you can have a layer called STUFF or any other name.
+// Layer names don't all need to be of the same length, obviously, and you can also skip them
+// entirely and just use numbers.
+
+// Fillers to make layering more clear
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {	
+	KEYMAP_V2(
+		KC_ESC, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_INS, KC_HOME, KC_PGUP, 
+		KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, KC_DEL, KC_END, KC_PGDN, 
+		KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_LBRC, KC_RBRC, KC_BSPC, KC_SLCK, 
+		KC_LCTL, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT, KC_TRNS, KC_ENT, KC_PAUS,  //modify KC_TRNS to enable ISO Support
+		KC_LSFT, KC_TRNS, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_B, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH, KC_LSFT, KC_UP, KC_PSCR, //modify KC_TRNS to enable ISO Support
+		KC_LCTL, KC_LGUI, KC_LALT, KC_SPC, MO(1), KC_SPC, KC_RALT, KC_RGUI, KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT),
+
+	KEYMAP_V2(
+		KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, RESET, 
+		KC_BSLS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_VOLU, KC_UP, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		M(1), KC_LEFT, KC_DOWN, KC_RGHT, KC_PAUS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_TRNS, KC_VOLD, M(0), KC_PSCR, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS),
+
+};

keyboards/deltasplit75/keymaps/itsaferbie/Makefile

@@ -0,0 +1,7 @@
+RGBLIGHT_ENABLE = yes        # Enable WS2812 RGB underlight.  Do not enable this with audio at the same time.
+AUDIO_ENABLE = no            # Audio disabled while using RGB underlight.
+EXTRAKEY_ENABLE = yes
+
+ifndef QUANTUM_DIR
+	include ../../../../Makefile
+endif

keyboards/deltasplit75/keymaps/itsaferbie/config.h

@@ -0,0 +1,31 @@
+/*
+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/>.
+*/
+
+
+#define USE_SERIAL
+
+#define MASTER_LEFT
+// #define _MASTER_RIGHT
+// #define EE_HANDS
+
+
+#ifdef SUBPROJECT_v2
+    #include "../../v2/config.h"
+#endif
+#ifdef SUBPROJECT_protosplit
+    #include "../../protosplit/config.h"
+#endif

keyboards/deltasplit75/keymaps/itsaferbie/keymap.c

@@ -0,0 +1,46 @@
+#include "deltasplit75.h"
+#include "action_layer.h"
+#include "eeconfig.h"
+
+extern keymap_config_t keymap_config;
+
+// Each layer gets a name for readability, which is then used in the keymap matrix below.
+// The underscores don't mean anything - you can have a layer called STUFF or any other name.
+// Layer names don't all need to be of the same length, obviously, and you can also skip them
+// entirely and just use numbers.
+
+// Fillers to make layering more clear
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {	
+	/* Layer 0: Default Layer
+     *,-----------------------------------------------------------------------.
+     * |Esc| F1| F2| F3| F4| F5| F6|    F7| F8| F9| F10| F11| F12|Prnt|Ins|Del| 
+	 * |----------------------------------------------------------------------|
+     * |  `|  1|  2|  3|  4|  5|  6|    7|  8|  9|  0|  -|  =| Backspace| Home|
+     * |----------------------------------------------------------------------|
+     * |Tab  |  Q|  W|  E|  R|  T|      Y|  U|  I|  O|  P|  [|  ]|  \|    PgUp|
+     * |----------------------------------------------------------------------|
+     * |Ctrl|  A|  S|  D|  F|  G|       H|  J|  K|  L|  ;|  '|Enter  |  PgDown|
+     * |----------------------------------------------------------------------|
+     * |Shif|   |  Z|  X|  C|  V|  B|   N|  M|  ,|  .|  /|Shift |      Up| End|
+     * |----------------------------------------------------------------------|
+     * |CapsLo|Gui |Alt |Sp |Mod |      Sp| Alt| Gui| Ctrl|    | Lef| Dow| Rig|
+     * `----------------------------------------------------------------------'
+     */
+	KEYMAP_V2(
+		KC_ESC,  KC_F1,   KC_F2,   KC_F3,  KC_F4, KC_F5,  KC_F6,            KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  KC_PSCR,  KC_INS,  KC_DEL, 
+		KC_GRV,  KC_1,    KC_2,    KC_3,   KC_4,  KC_5,   KC_6,             KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS, KC_EQL,  KC_BSPC,  KC_TRNS, KC_HOME, // KC_TRNS is the unneeded key in the split backspace.
+		KC_TAB,  KC_Q,    KC_W,    KC_E,   KC_R,  KC_T,                     KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_LBRC, KC_RBRC,  KC_BSLS, KC_PGUP, 
+		KC_LCTL, KC_A,    KC_S,    KC_D,   KC_F,  KC_G,                     KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_QUOT, KC_TRNS,  KC_ENT,  KC_PGDN, // KC_TRNS is unneeded ISO enter key. 
+		KC_LSFT, KC_TRNS, KC_Z,    KC_X,   KC_C,  KC_V,   KC_B,             KC_B,    KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_RSFT,  KC_UP,   KC_END,  // KC_TRNS is uneeded ISO layout key.
+		KC_CAPS, KC_LGUI, KC_LALT,         KC_SPC, MO(1),                   KC_SPC,  KC_RALT, KC_RGUI, KC_RCTL,                   KC_LEFT,  KC_DOWN, KC_RGHT),
+
+	KEYMAP_V2(
+		RGB_TOG, RGB_HUI, RGB_SAI, RGB_VAI, KC_TRNS, KC_TRNS, KC_TRNS,      KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, RESET, 
+		RGB_MOD, RGB_HUD, RGB_SAD, RGB_VAD, KC_TRNS, KC_TRNS, KC_TRNS,      KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,               KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,               KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_VOLU, 
+		KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,      KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_MPLY, KC_VOLD, 
+		KC_TRNS, KC_TRNS, KC_TRNS,          KC_TRNS, KC_TRNS,               KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,                   KC_MPRV, KC_STOP, KC_MNXT),
+
+};

keyboards/deltasplit75/keymaps/protosplit/config.h

@@ -0,0 +1,31 @@
+/*
+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/>.
+*/
+
+
+#define USE_SERIAL
+
+#define MASTER_LEFT
+// #define _MASTER_RIGHT
+// #define EE_HANDS
+
+
+#ifdef SUBPROJECT_v2
+    #include "../../v2/config.h"
+#endif
+#ifdef SUBPROJECT_protosplit
+    #include "../../protosplit/config.h"
+#endif

keyboards/deltasplit75/keymaps/protosplit/keymap.c

@@ -0,0 +1,32 @@
+#include "deltasplit75.h"
+#include "action_layer.h"
+#include "eeconfig.h"
+
+extern keymap_config_t keymap_config;
+
+// Each layer gets a name for readability, which is then used in the keymap matrix below.
+// The underscores don't mean anything - you can have a layer called STUFF or any other name.
+// Layer names don't all need to be of the same length, obviously, and you can also skip them
+// entirely and just use numbers.
+
+// Fillers to make layering more clear
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {	
+	KEYMAP_PROTOSPLIT(
+		KC_ESC, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_INS, KC_HOME, KC_PGUP, 
+		KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, KC_DEL, KC_END, KC_PGDN, 
+		KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_LBRC, KC_RBRC, KC_BSPC, KC_SLCK, 
+		KC_LCTL, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT, KC_ENT, KC_PAUS,
+		KC_LSFT, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_B, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH, KC_LSFT, KC_UP, KC_PSCR,
+		KC_LCTL, KC_LGUI, KC_LALT, KC_SPC, MO(1), KC_SPC, KC_RALT, KC_RGUI, KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT),
+
+	KEYMAP_PROTOSPLIT(
+		KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, RESET, 
+		KC_BSLS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_VOLU, KC_UP, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		M(1), KC_LEFT, KC_DOWN, KC_RGHT, KC_PAUS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_VOLD, M(0), KC_PSCR, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, 
+		KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS),
+		
+
+};

keyboards/deltasplit75/readme.md

@@ -0,0 +1,137 @@
+DeltaSplit75
+======
+
+This readme and most of the code are from https://github.com/ahtn/tmk_keyboard/ and https://github.com/qmk/qmk_firmware/tree/master/keyboards/lets_split
+
+Credit to ahtn and wootpatoot for work on the split keyboard firmware
+
+Split keyboard firmware for Arduino Pro Micro or other ATmega32u4
+based boards.
+
+## Case Files
+Files are available here: https://github.com/xyxjj/DeltaSplit75-Case-files
+
+## Build Guide
+The build guide should be found at https://qmk.fm/deltasplit75
+
+
+## First Time Setup
+
+Download or clone the whole firmware and navigate to the keyboards/deltasplit75 directory. Once your dev env is setup, you'll be able to generate the .hex using:
+
+```
+make v2
+
+or
+
+make v2-YOUR_KEYMAP_NAME (if you make a folder for your keymap)
+
+or
+
+make protosplit (if you have one of the prototype PCBs)
+```
+
+You will see a lot of output and if everything worked correctly you will see the built hex files:
+
+```
+deltasplit75_v2_protosplit.hex 
+
+or
+
+deltasplit74_v2_YOUR_KEYMAP_NAME.hex
+
+or
+
+deltasplit75_v2_default.hex
+
+```
+
+
+For more information on customizing keymaps, take a look at the primary documentation for [Customizing Your Keymap](/readme.md##customizing-your-keymap) in the main readme.md.
+
+### DeltaSplit75 V2
+The PCBs available in groupbuy are all v2, if you've bought one of my prototype PCBs (it says DeltaSplit65 on the silkscreen instead of 75), use the code make protosplit instead
+
+Features
+--------
+
+For the full Quantum Mechanical Keyboard feature list, see [the parent readme.md](/readme.md).
+
+Some features supported by the firmware:
+
+* Either half can connect to the computer via USB, or both halves can be used
+  independently.
+* 75% formfactor
+* Support for multiple Bottom Rows
+* RGB underglow support
+* Split Backspace and ISO support
+
+
+Flashing
+-------
+I personally use xLoader to upload my hex files to the keyboard, though any other working software is fine too
+
+
+Choosing which board to plug the USB cable into (choosing Master)
+--------
+Because the two boards are identical, the firmware has logic to differentiate the left and right board.
+
+It uses two strategies to figure things out: look at the EEPROM (memory on the chip) or looks if the current board has the usb cable.
+
+The EEPROM approach requires additional setup (flashing the eeeprom) but allows you to swap the usb cable to either side.
+
+The USB cable approach is easier to setup and if you just want the usb cable on the left board, you do not need to do anything extra.
+
+### Setting the left hand as master
+If you always plug the usb cable into the left board, nothing extra is needed as this is the default. Comment out `EE_HANDS` and comment out `I2C_MASTER_RIGHT` or `MASTER_RIGHT` if for some reason it was set.
+
+### Setting the right hand as master
+If you always plug the usb cable into the right board, add an extra flag to your `config.h`
+```
+ #define MASTER_RIGHT
+```
+
+### Setting EE_hands to use either hands as master
+If you define `EE_HANDS` in your `config.h`, you will need to set the
+EEPROM for the left and right halves.
+
+The EEPROM is used to store whether the
+half is left handed or right handed. This makes it so that the same firmware
+file will run on both hands instead of having to flash left and right handed
+versions of the firmware to each half. To flash the EEPROM file for the left
+half run:
+```
+avrdude -p atmega32u4 -P $(COM_PORT) -c avr109 -U eeprom:w:eeprom-lefthand.eep
+// or the equivalent in dfu-programmer
+
+```
+and similarly for right half
+```
+avrdude -p atmega32u4 -P $(COM_PORT) -c avr109 -U eeprom:w:eeprom-righhand.eep
+// or the equivalent in dfu-programmer
+```
+
+NOTE: replace `$(COM_PORT)` with the port of your device (e.g. `/dev/ttyACM0`)
+
+After you have flashed the EEPROM, you then need to set `EE_HANDS` in your config.h, rebuild the hex files and reflash.
+
+Note that you need to program both halves, but you have the option of using
+different keymaps for each half. You could program the left half with a QWERTY
+layout and the right half with a Colemak layout using bootmagic's default layout option.
+Then if you connect the left half to a computer by USB the keyboard will use QWERTY and Colemak when the
+right half is connected.
+
+
+Notes on Using Pro Micro 3.3V
+-----------------------------
+
+Do update the `F_CPU` parameter in `rules.mk` to `8000000` which reflects
+the frequency on the 3.3V board.
+
+Also, if the slave board is producing weird characters in certain columns,
+update the following line in `matrix.c` to the following:
+
+```
+// _delay_us(30);  // without this wait read unstable value.
+_delay_us(300);  // without this wait read unstable value.
+```

keyboards/deltasplit75/rules.mk

@@ -0,0 +1,87 @@
+SRC += matrix.c \
+	   i2c.c \
+	   split_util.c \
+	   serial.c
+
+# MCU name
+#MCU = at90usb1287
+MCU = atmega32u4
+
+# 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
+
+
+# Boot Section Size in *bytes*
+#   Teensy halfKay   512
+#   Teensy++ halfKay 1024
+#   Atmel DFU loader 4096
+#   LUFA bootloader  4096
+#   USBaspLoader     2048
+OPT_DEFS += -DBOOTLOADER_SIZE=4096
+
+# Build Options
+#   change to "no" to disable the options, or define them in the Makefile in
+#   the appropriate keymap folder that will get included automatically
+#
+BOOTMAGIC_ENABLE ?= no       # 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 ?= yes        # Commands for debug and configuration
+NKRO_ENABLE ?= no            # Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
+BACKLIGHT_ENABLE ?= no      # Enable keyboard backlight functionality
+MIDI_ENABLE ?= no            # MIDI controls
+AUDIO_ENABLE ?= no           # Audio output on port C6
+UNICODE_ENABLE ?= no         # Unicode
+BLUETOOTH_ENABLE ?= no       # Enable Bluetooth with the Adafruit EZ-Key HID
+RGBLIGHT_ENABLE ?= no       # Enable WS2812 RGB underlight.  Do not enable this with audio at the same time.
+SUBPROJECT_rev1 ?= yes
+USE_I2C ?= yes
+# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
+SLEEP_LED_ENABLE ?= no    # Breathing sleep LED during USB suspend
+
+CUSTOM_MATRIX = yes
+
+avrdude: build
+	ls /dev/tty* > /tmp/1; \
+	echo "Reset your Pro Micro now"; \
+	while [[ -z $$USB ]]; do \
+	  sleep 1; \
+	  ls /dev/tty* > /tmp/2; \
+	  USB=`diff /tmp/1 /tmp/2 | grep -o '/dev/tty.*'`; \
+	done; \
+	avrdude -p $(MCU) -c avr109 -P $$USB -U flash:w:$(BUILD_DIR)/$(TARGET).hex
+
+.PHONY: avrdude

keyboards/deltasplit75/serial.c

@@ -0,0 +1,228 @@
+/*
+ * WARNING: be careful changing this code, it is very timing dependent
+ */
+
+#ifndef F_CPU
+#define F_CPU 16000000
+#endif
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <stdbool.h>
+#include "serial.h"
+
+#ifdef USE_SERIAL
+
+// Serial pulse period in microseconds. Its probably a bad idea to lower this
+// value.
+#define SERIAL_DELAY 24
+
+uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
+uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
+
+#define SLAVE_DATA_CORRUPT (1<<0)
+volatile uint8_t status = 0;
+
+inline static
+void serial_delay(void) {
+  _delay_us(SERIAL_DELAY);
+}
+
+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(void) {
+  SERIAL_PIN_DDR  &= ~SERIAL_PIN_MASK;
+  SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
+}
+
+inline static
+uint8_t serial_read_pin(void) {
+  return !!(SERIAL_PIN_INPUT & SERIAL_PIN_MASK);
+}
+
+inline static
+void serial_low(void) {
+  SERIAL_PIN_PORT &= ~SERIAL_PIN_MASK;
+}
+
+inline static
+void serial_high(void) {
+  SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
+}
+
+void serial_master_init(void) {
+  serial_output();
+  serial_high();
+}
+
+void serial_slave_init(void) {
+  serial_input();
+
+  // Enable INT0
+  EIMSK |= _BV(INT0);
+  // Trigger on falling edge of INT0
+  EICRA &= ~(_BV(ISC00) | _BV(ISC01));
+}
+
+// Used by the master to synchronize timing with the slave.
+static
+void sync_recv(void) {
+  serial_input();
+  // This shouldn't hang if the slave disconnects because the
+  // serial line will float to high if the slave does disconnect.
+  while (!serial_read_pin());
+  serial_delay();
+}
+
+// Used by the slave to send a synchronization signal to the master.
+static
+void sync_send(void) {
+  serial_output();
+
+  serial_low();
+  serial_delay();
+
+  serial_high();
+}
+
+// Reads a byte from the serial line
+static
+uint8_t serial_read_byte(void) {
+  uint8_t byte = 0;
+  serial_input();
+  for ( uint8_t i = 0; i < 8; ++i) {
+    byte = (byte << 1) | serial_read_pin();
+    serial_delay();
+    _delay_us(1);
+  }
+
+  return byte;
+}
+
+// Sends a byte with MSB ordering
+static
+void serial_write_byte(uint8_t data) {
+  uint8_t b = 8;
+  serial_output();
+  while( b-- ) {
+    if(data & (1 << b)) {
+      serial_high();
+    } else {
+      serial_low();
+    }
+    serial_delay();
+  }
+}
+
+// interrupt handle to be used by the slave device
+ISR(SERIAL_PIN_INTERRUPT) {
+  sync_send();
+
+  uint8_t checksum = 0;
+  for (int i = 0; i < SERIAL_SLAVE_BUFFER_LENGTH; ++i) {
+    serial_write_byte(serial_slave_buffer[i]);
+    sync_send();
+    checksum += serial_slave_buffer[i];
+  }
+  serial_write_byte(checksum);
+  sync_send();
+
+  // wait for the sync to finish sending
+  serial_delay();
+
+  // read the middle of pulses
+  _delay_us(SERIAL_DELAY/2);
+
+  uint8_t checksum_computed = 0;
+  for (int i = 0; i < SERIAL_MASTER_BUFFER_LENGTH; ++i) {
+    serial_master_buffer[i] = serial_read_byte();
+    sync_send();
+    checksum_computed += serial_master_buffer[i];
+  }
+  uint8_t checksum_received = serial_read_byte();
+  sync_send();
+
+  serial_input(); // end transaction
+
+  if ( checksum_computed != checksum_received ) {
+    status |= SLAVE_DATA_CORRUPT;
+  } else {
+    status &= ~SLAVE_DATA_CORRUPT;
+  }
+}
+
+inline
+bool serial_slave_DATA_CORRUPT(void) {
+  return status & SLAVE_DATA_CORRUPT;
+}
+
+// Copies the serial_slave_buffer to the master and sends the
+// serial_master_buffer to the slave.
+//
+// Returns:
+// 0 => no error
+// 1 => slave did not respond
+int serial_update_buffers(void) {
+  // this code is very time dependent, so we need to disable interrupts
+  cli();
+
+  // signal to the slave that we want to start a transaction
+  serial_output();
+  serial_low();
+  _delay_us(1);
+
+  // wait for the slaves response
+  serial_input();
+  serial_high();
+  _delay_us(SERIAL_DELAY);
+
+  // check if the slave is present
+  if (serial_read_pin()) {
+    // slave failed to pull the line low, assume not present
+    sei();
+    return 1;
+  }
+
+  // if the slave is present syncronize with it
+  sync_recv();
+
+  uint8_t checksum_computed = 0;
+  // receive data from the slave
+  for (int i = 0; i < SERIAL_SLAVE_BUFFER_LENGTH; ++i) {
+    serial_slave_buffer[i] = serial_read_byte();
+    sync_recv();
+    checksum_computed += serial_slave_buffer[i];
+  }
+  uint8_t checksum_received = serial_read_byte();
+  sync_recv();
+
+  if (checksum_computed != checksum_received) {
+    sei();
+    return 1;
+  }
+
+  uint8_t checksum = 0;
+  // send data to the slave
+  for (int i = 0; i < SERIAL_MASTER_BUFFER_LENGTH; ++i) {
+    serial_write_byte(serial_master_buffer[i]);
+    sync_recv();
+    checksum += serial_master_buffer[i];
+  }
+  serial_write_byte(checksum);
+  sync_recv();
+
+  // always, release the line when not in use
+  serial_output();
+  serial_high();
+
+  sei();
+  return 0;
+}
+
+#endif

keyboards/deltasplit75/serial.h

@@ -0,0 +1,26 @@
+#ifndef MY_SERIAL_H
+#define MY_SERIAL_H
+
+#include "config.h"
+#include <stdbool.h>
+
+/* TODO:  some defines for interrupt setup */
+#define SERIAL_PIN_DDR DDRD
+#define SERIAL_PIN_PORT PORTD
+#define SERIAL_PIN_INPUT PIND
+#define SERIAL_PIN_MASK _BV(PD0)
+#define SERIAL_PIN_INTERRUPT INT0_vect
+
+#define SERIAL_SLAVE_BUFFER_LENGTH ((MATRIX_COLS+7)/8 *MATRIX_ROWS/2)
+#define SERIAL_MASTER_BUFFER_LENGTH 1
+
+// Buffers for master - slave communication
+extern volatile uint8_t serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH];
+extern volatile uint8_t serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH];
+
+void serial_master_init(void);
+void serial_slave_init(void);
+int serial_update_buffers(void);
+bool serial_slave_data_corrupt(void);
+
+#endif

keyboards/deltasplit75/split_util.c

@@ -0,0 +1,81 @@
+#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 "config.h"
+
+#ifdef USE_I2C
+#  include "i2c.h"
+#else
+#  include "serial.h"
+#endif
+
+volatile bool isLeftHand = true;
+
+static void setup_handedness(void) {
+  #ifdef EE_HANDS
+    isLeftHand = eeprom_read_byte(EECONFIG_HANDEDNESS);
+  #else
+    // I2C_MASTER_RIGHT is deprecated use MASTER_RIGHT instead since this works for both serial and i2c
+    #if defined(I2C_MASTER_RIGHT) || defined(MASTER_RIGHT)
+      isLeftHand = !has_usb();
+    #else
+      isLeftHand = has_usb();
+    #endif
+  #endif
+}
+
+static void keyboard_master_setup(void) {
+#ifdef USE_I2C
+    i2c_master_init();
+#else
+    serial_master_init();
+#endif
+}
+
+static void keyboard_slave_setup(void) {
+#ifdef USE_I2C
+    i2c_slave_init(SLAVE_I2C_ADDRESS);
+#else
+    serial_slave_init();
+#endif
+}
+
+bool has_usb(void) {
+   USBCON |= (1 << OTGPADE); //enables VBUS pad
+   _delay_us(5);
+   return (USBSTA & (1<<VBUS));  //checks state of VBUS
+}
+
+void split_keyboard_setup(void) {
+   setup_handedness();
+
+   if (has_usb()) {
+      keyboard_master_setup();
+   } else {
+      keyboard_slave_setup();
+   }
+   sei();
+}
+
+void keyboard_slave_loop(void) {
+   matrix_init();
+
+   while (1) {
+      matrix_slave_scan();
+   }
+}
+
+// this code runs before the usb and keyboard is initialized
+void matrix_setup(void) {
+    split_keyboard_setup();
+
+    if (!has_usb()) {
+        keyboard_slave_loop();
+    }
+}

keyboards/deltasplit75/split_util.h

@@ -0,0 +1,22 @@
+#ifndef SPLIT_KEYBOARD_UTIL_H
+#define SPLIT_KEYBOARD_UTIL_H
+
+#include <stdbool.h>
+
+#ifdef EE_HANDS
+	#define EECONFIG_BOOTMAGIC_END      (uint8_t *)10
+	#define EECONFIG_HANDEDNESS         EECONFIG_BOOTMAGIC_END
+#endif
+
+#define SLAVE_I2C_ADDRESS           0x32
+
+extern volatile bool isLeftHand;
+
+// slave version of matix scan, defined in matrix.c
+void matrix_slave_scan(void);
+
+void split_keyboard_setup(void);
+bool has_usb(void);
+void keyboard_slave_loop(void);
+
+#endif

keyboards/deltasplit75/v2/Makefile

@@ -0,0 +1,3 @@
+ifndef MAKEFILE_INCLUDED
+	include ../../Makefile
+endif

keyboards/deltasplit75/v2/config.h

@@ -0,0 +1,90 @@
+/*
+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/>.
+*/
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include "config_common.h"
+
+/* USB Device descriptor parameter */
+#define VENDOR_ID       0xFEED
+#define PRODUCT_ID      0x3060
+#define DEVICE_VER      0x0001
+#define MANUFACTURER    xyxjj
+#define PRODUCT         DeltaSplit75
+#define DESCRIPTION     75% split keyboard
+
+/* key matrix size */
+// Rows are doubled-up
+#define MATRIX_ROWS 14
+#define MATRIX_COLS 8
+
+// wiring of each half
+#define MATRIX_ROW_PINS { F4, F5, F6, F7, B1, B3, B2 }
+#define MATRIX_COL_PINS { B6, B5, B4, E6, D7, C6, D4, D1}
+
+#define CATERINA_BOOTLOADER
+
+/* COL2ROW or ROW2COL */
+#define DIODE_DIRECTION COL2ROW
+
+/* define if matrix has ghost */
+//#define MATRIX_HAS_GHOST
+
+/* number of backlight levels */
+// #define BACKLIGHT_LEVELS 3
+
+/* Set 0 if debouncing isn't needed */
+#define DEBOUNCING_DELAY 5
+
+/* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
+#define LOCKING_SUPPORT_ENABLE
+/* Locking resynchronize hack */
+#define LOCKING_RESYNC_ENABLE
+
+/* key combination for command */
+#define IS_COMMAND() ( \
+    keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)) \
+)
+
+/* ws2812 RGB LED */
+#define RGB_DI_PIN D3
+#define RGBLIGHT_TIMER
+#define RGBLED_NUM 12    // Number of LEDs
+#define ws2812_PORTREG  PORTD
+#define ws2812_DDRREG   DDRD
+
+/*
+ * Feature disable options
+ *  These options are also useful to firmware size reduction.
+ */
+
+/* disable debug print */
+// #define NO_DEBUG
+
+/* disable print */
+// #define NO_PRINT
+
+/* disable action features */
+//#define NO_ACTION_LAYER
+//#define NO_ACTION_TAPPING
+//#define NO_ACTION_ONESHOT
+//#define NO_ACTION_MACRO
+//#define NO_ACTION_FUNCTION
+
+
+#endif

keyboards/deltasplit75/v2/rules.mk

@@ -0,0 +1,5 @@
+BACKLIGHT_ENABLE = no
+
+ifndef QUANTUM_DIR
+	include ../../../Makefile
+endif

keyboards/deltasplit75/v2/v2.c

@@ -0,0 +1,14 @@
+#include "deltasplit75.h"
+
+void matrix_init_kb(void) {
+    // // green led on
+    // DDRD |= (1<<5);
+    // PORTD &= ~(1<<5);
+
+    // // orange led on
+    // DDRB |= (1<<0);
+    // PORTB &= ~(1<<0);
+
+	matrix_init_user();
+};
+