~ruther/qmk_firmware

e921b9a77e36787704e3f5480b525fcaa97cf08b — omkbd 7 years ago 96546c7
Add ErgoDash keyboard (#3128)

* create ergodash

* Revert "create ergodash"

This reverts commit b261c808c30fee95cb656629f7e9b44b01e79363.

* add ergodash

* keymap→layout

* use set_single_persistent_default_layer
A keyboards/ergodash/config.h => keyboards/ergodash/config.h +24 -0
@@ 0,0 1,24 @@
/*
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/>.
*/

#ifndef CONFIG_H
#define CONFIG_H

#include "config_common.h"

#endif

A keyboards/ergodash/ergodash.c => keyboards/ergodash/ergodash.c +1 -0
@@ 0,0 1,1 @@
#include "ergodash.h"

A keyboards/ergodash/ergodash.h => keyboards/ergodash/ergodash.h +29 -0
@@ 0,0 1,29 @@
#ifndef ERGODASH_H
#define ERGODASH_H

#include "quantum.h"

#ifdef KEYBOARD_ergodash_rev1
    #include "rev1.h"
#endif


// Used to create a keymap using only KC_ prefixed keys
#define LAYOUT_kc( \
    L00, L01, L02, L03, L04, L05, L06, R00, R01, R02, R03, R04, R05, R06, \
    L10, L11, L12, L13, L14, L15, L16, R10, R11, R12, R13, R14, R15, R16, \
    L20, L21, L22, L23, L24, L25, L26, R20, R21, R22, R23, R24, R25, R26, \
    L30, L31, L32, L33, L34, L35, L36, R30, R31, R32, R33, R34, R35, R36, \
    LT0, LT1, LT2, LT3,      LT4, LT5, RT0, RT1,      RT2, RT3, RT4, RT5  \
    ) \
    LAYOUT( \
        KC_##L00, KC_##L01, KC_##L02, KC_##L03, KC_##L04, KC_##L05, KC_##L06, KC_##R00, KC_##R01, KC_##R02, KC_##R03, KC_##R04, KC_##R05, KC_##R06, \
        KC_##L10, KC_##L11, KC_##L12, KC_##L13, KC_##L14, KC_##L15, KC_##L16, KC_##R10, KC_##R11, KC_##R12, KC_##R13, KC_##R14, KC_##R15, KC_##R16, \
        KC_##L20, KC_##L21, KC_##L22, KC_##L23, KC_##L24, KC_##L25, KC_##L26, KC_##R20, KC_##R21, KC_##R22, KC_##R23, KC_##R24, KC_##R25, KC_##R26, \
        KC_##L30, KC_##L31, KC_##L32, KC_##L33, KC_##L34, KC_##L35, KC_##L36, KC_##R30, KC_##R31, KC_##R32, KC_##R33, KC_##R34, KC_##R35, KC_##R36, \
        KC_##LT0, KC_##LT1, KC_##LT2, KC_##LT3,           KC_##LT4, KC_##LT5, KC_##RT0, KC_##RT1,           KC_##RT2, KC_##RT3, KC_##RT4, KC_##RT5  \
    )

#define KC_LAYOUT_ortho_5x14 KC_KEYMAP

#endif

A keyboards/ergodash/i2c.c => keyboards/ergodash/i2c.c +162 -0
@@ 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

A keyboards/ergodash/i2c.h => keyboards/ergodash/i2c.h +49 -0
@@ 0,0 1,49 @@
#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  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();

#endif

A keyboards/ergodash/keymaps/default/config.h => keyboards/ergodash/keymaps/default/config.h +44 -0
@@ 0,0 1,44 @@
/*
This is the c configuration file for the keymap

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/>.
*/

#ifndef CONFIG_USER_H
#define CONFIG_USER_H

#include "../../config.h"

/* Use I2C or Serial, not both */

#define USE_SERIAL
// #define USE_I2C

/* Select hand configuration */

#define MASTER_LEFT
// #define MASTER_RIGHT
// #define EE_HANDS

#endif

#undef RGBLED_NUM
#define RGBLIGHT_ANIMATIONS
#define RGBLED_NUM 24
#define RGBLIGHT_HUE_STEP 10
#define RGBLIGHT_SAT_STEP 17
#define RGBLIGHT_VAL_STEP 17

A keyboards/ergodash/keymaps/default/keymap.c => keyboards/ergodash/keymaps/default/keymap.c +163 -0
@@ 0,0 1,163 @@
#include QMK_KEYBOARD_H
#include "action_layer.h"
#include "eeconfig.h"

extern keymap_config_t keymap_config;

#define _QWERTY 0
#define _LOWER 1
#define _RAISE 2
#define _ADJUST 16

enum custom_keycodes {
  QWERTY = SAFE_RANGE,
  LOWER,
  RAISE,
  ADJUST,
};

// Fillers to make layering more clear
#define KC_ KC_TRNS
#define _______ KC_TRNS
#define XXXXXXX KC_NO
#define KC_AJST ADJUST
#define KC_LOWR LOWER
#define KC_RASE RAISE
#define KC_JPN LALT(KC_GRV)

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {

/* Qwerty
 * ,-------------------------------------------------------------------------------------------------.
 * | ESC  |   1  |   2  |   3  |   4  |   5  |   [  |   ]  |   6  |   7  |   8  |   9  |   0  | Caps |
 * |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
 * |  `   |   Q  |   W  |   E  |   R  |   T  |   -  |   =  |   Y  |   U  |   I  |   O  |   P  |  \   |
 * |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
 * | Tab  |   A  |   S  |   D  |   F  |   G  |  Del | Bksp |   H  |   J  |   K  |   L  |   ;  |  "   |
 * |------+------+------+------+------+------+-------------+------+------+------+------+------+------|
 * | Shift|   Z  |   X  |   C  |   V  |   B  |  JPN | Enter|   N  |   M  |   ,  |   .  |   /  | Shift|
 * `-------------+------+------+------+------+------+------+------+------+------+------+-------------'
 * | Ctrl |  GUI |  ALt |Adjust|      |Lower | Space |Enter |Raise|      |  Left| Down |  Up  | Right|
 * ,-------------------------------------------------------------------------------------------------.
 */
[_QWERTY] = LAYOUT( \
  KC_ESC,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_LBRC,       KC_RBRC, KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_CAPS, \
  KC_GRV,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_MINS,       KC_EQL , KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_BSLS, \
  KC_TAB,  KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_DEL ,       KC_BSPC, KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_QUOT, \
  KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_JPN ,       KC_ENT , KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_RSFT, \
  KC_LCTL, KC_LGUI, KC_LALT, KC_AJST,          KC_LOWR, KC_SPC ,       KC_ENT , KC_RASE,          KC_LEFT, KC_DOWN, KC_UP,   KC_RGHT  \
),

/* Lower
* ,-------------------------------------------------------------------------------------------------.
* | F11  |  F1  |  F2  |  F3  |  F4  |  F5  |   {  |   }  |  F6  |  F7  |  F8  |  F9  |  F10 | F12  |
* |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
* |  ~  |   !  |   @  |   #  |   $  |   %  |   _  |   +  |   ^  |   &  |   *  |   (  |    )  |  |   |
* |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
* | Tab  |   A  |   S  |   D  |   F  |   G  |  Del | Bksp |   H  |   J  |   K  |   L  |   :  |  "   |
* |------+------+------+------+------+------+-------------+------+------+------+------+------+------|
* | Shift|   Z  |   X  |   C  |   V  |   B  |  JPN | Enter|   N  |   M  |   <  |   >  |   ?  | Shift|
* `-------------+------+------+------+------+------+------+------+------+------+------+-------------'
* | Ctrl |  GUI |  ALt |Adjust|      |Lower | Space |Enter |Raise|      | Home |PageDn|PageUp|  End |
* ,-------------------------------------------------------------------------------------------------.
 */
 [_LOWER] = LAYOUT(
  KC_F11,  KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_LCBR,       KC_RCBR, KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F12,  \
  KC_TILD, KC_EXLM, KC_AT,   KC_HASH, KC_DLR,  KC_PERC, KC_UNDS,       KC_PLUS, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_PIPE, \
  KC_TAB,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_DEL ,       KC_BSPC, KC_H,    KC_J,    KC_K,    KC_L,    KC_COLN, KC_DQT , \
  KC_LSFT, KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_JPN ,       KC_ENT , KC_N,    KC_M,    KC_LT,   KC_GT,   KC_QUES, KC_RSFT, \
  KC_LCTL, KC_LGUI, KC_LALT, KC_AJST,          KC_LOWR, KC_SPC ,       KC_ENT , KC_RASE,          KC_HOME, KC_PGDN, KC_PGUP, KC_END   \
 ),

/* Raise
* ,-------------------------------------------------------------------------------------------------.
* | F11  |  F1  |  F2  |  F3  |  F4  |  F5  |   {  |   }  |  F6  |  F7  |  F8  |  F9  |  F10 | F12  |
* |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
* |  ~  |   !  |   @  |   #  |   $  |   %  |   _  |   +  |   ^  |   &  |   *  |   (  |    )  |  |   |
* |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
* | Tab  |   A  |   S  |   D  |   F  |   G  |  Del | Bksp |   H  |   J  |   K  |   L  |   :  |  "   |
* |------+------+------+------+------+------+-------------+------+------+------+------+------+------|
* | Shift|   Z  |   X  |   C  |   V  |   B  |  JPN | Enter|   N  |   M  |   <  |   >  |   ?  | Shift|
* `-------------+------+------+------+------+------+------+------+------+------+------+-------------'
* | Ctrl |  GUI |  ALt |Adjust|      |Lower | Space |Enter |Raise|      | Home |PageDn|PageUp|  End |
* ,-------------------------------------------------------------------------------------------------.
 */
  [_RAISE] = LAYOUT(
  KC_F11,  KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_LCBR,       KC_RCBR, KC_F6,   KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F12,  \
  KC_TILD, KC_EXLM, KC_AT,   KC_HASH, KC_DLR,  KC_PERC, KC_UNDS,       KC_PLUS, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_PIPE, \
  KC_TAB,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_DEL ,       KC_BSPC, KC_H,    KC_J,    KC_K,    KC_L,    KC_COLN, KC_DQT , \
  KC_LSFT, KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_JPN ,       KC_ENT , KC_N,    KC_M,    KC_LT,   KC_GT,   KC_QUES, KC_RSFT, \
  KC_LCTL, KC_LGUI, KC_LALT, KC_AJST,          KC_LOWR, KC_SPC ,       KC_ENT , KC_RASE,          KC_HOME, KC_PGDN, KC_PGUP, KC_END   \
 ),

 /* Adjust
 * ,-------------------------------------------------------------------------------------------------.
 * |      |      |      |      |      |      |      |      |      |      |      |      |      |      |
 * |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
 * |      | Reset|RGB ON|  MODE|  HUE-|  HUE+|      |      |  SAT-|  SAT+|  VAL-|  VAL+|      |      |
 * |------+------+------+------+------+------+------+------+------+------+------+------+------+------|
 * |      |      |      |      |      |      |      |      |      |      |      |      |      |      |
 * |------+------+------+------+------+------+-------------+------+------+------+------+------+------|
 * |      |      |      |      |      |      |      |      |      |      |      |      |      |      |
 * `-------------+------+------+------+------+------+------+------+------+------+------+-------------'
 * |      |      |      |      |      |      |      |      |      |      |      |      |      |      |
 * ,-------------------------------------------------------------------------------------------------.
  */
  [_ADJUST] = LAYOUT(
  _______, _______, _______, _______, _______, _______,_______,       _______, _______, _______, _______, _______, _______, _______, \
  _______, RESET  , RGB_TOG, RGB_MOD, RGB_HUD, RGB_HUI,_______,       _______, RGB_SAD, RGB_SAI, RGB_VAD, RGB_VAI, _______, _______, \
  _______, _______, _______, _______, _______, _______,_______,       _______, _______, _______, _______, _______, _______, _______, \
  _______, _______, _______, _______, _______, _______,_______,       _______, _______, _______, _______, _______, _______, _______, \
  _______, _______, _______, _______,          _______,_______,       _______, _______,          _______, _______, _______, _______ \
  )
};

#ifdef AUDIO_ENABLE
float tone_qwerty[][2]     = SONG(QWERTY_SOUND);
#endif

void persistent_default_layer_set(uint16_t default_layer) {
  eeconfig_update_default_layer(default_layer);
  default_layer_set(default_layer);
}

bool process_record_user(uint16_t keycode, keyrecord_t *record) {
  switch (keycode) {
    case QWERTY:
      if (record->event.pressed) {
         print("mode just switched to qwerty and this is a huge string\n");
        set_single_persistent_default_layer(_QWERTY);
      }
      return false;
      break;
    case LOWER:
      if (record->event.pressed) {
        layer_on(_LOWER);
        update_tri_layer(_LOWER, _RAISE, _ADJUST);
      } else {
        layer_off(_LOWER);
        update_tri_layer(_LOWER, _RAISE, _ADJUST);
      }
      return false;
      break;
    case RAISE:
      if (record->event.pressed) {
        layer_on(_RAISE);
        update_tri_layer(_LOWER, _RAISE, _ADJUST);
      } else {
        layer_off(_RAISE);
        update_tri_layer(_LOWER, _RAISE, _ADJUST);
      }
      return false;
      break;
    case ADJUST:
      if (record->event.pressed) {
        layer_on(_ADJUST);
      } else {
        layer_off(_ADJUST);
      }
      return false;
      break;
  }
  return true;
}

A keyboards/ergodash/keymaps/default/rules.mk => keyboards/ergodash/keymaps/default/rules.mk +0 -0
A keyboards/ergodash/matrix.c => keyboards/ergodash/matrix.c +460 -0
@@ 0,0 1,460 @@
/*
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 <avr/io.h>
#include "wait.h"
#include "print.h"
#include "debug.h"
#include "util.h"
#include "matrix.h"
#include "split_util.h"
#include "pro_micro.h"
#include "config.h"
#include "timer.h"

#ifdef USE_I2C
#  include "i2c.h"
#else // USE_SERIAL
#  include "serial.h"
#endif

#ifndef DEBOUNCING_DELAY
#   define DEBOUNCING_DELAY 5
#endif

#if (DEBOUNCING_DELAY > 0)
    static uint16_t debouncing_time;
    static bool debouncing = false;
#endif

#if (MATRIX_COLS <= 8)
#    define print_matrix_header()  print("\nr/c 01234567\n")
#    define print_matrix_row(row)  print_bin_reverse8(matrix_get_row(row))
#    define matrix_bitpop(i)       bitpop(matrix[i])
#    define ROW_SHIFTER ((uint8_t)1)
#else
#    error "Currently only supports 8 COLS"
#endif
static matrix_row_t matrix_debouncing[MATRIX_ROWS];

#define ERROR_DISCONNECT_COUNT 5

#define ROWS_PER_HAND (MATRIX_ROWS/2)

static uint8_t error_count = 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];

#if (DIODE_DIRECTION == COL2ROW)
    static void init_cols(void);
    static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row);
    static void unselect_rows(void);
    static void select_row(uint8_t row);
    static void unselect_row(uint8_t row);
#elif (DIODE_DIRECTION == ROW2COL)
    static void init_rows(void);
    static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col);
    static void unselect_cols(void);
    static void unselect_col(uint8_t col);
    static void select_col(uint8_t col);
#endif

__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 matrix_init(void)
{
    debug_enable = true;
    debug_matrix = true;
    debug_mouse = true;
    // initialize row and col
#if (DIODE_DIRECTION == COL2ROW)
    unselect_rows();
    init_cols();
#elif (DIODE_DIRECTION == ROW2COL)
    unselect_cols();
    init_rows();
#endif

    TX_RX_LED_INIT;

    // initialize matrix state: all keys off
    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
        matrix[i] = 0;
        matrix_debouncing[i] = 0;
    }

    matrix_init_quantum();

}

uint8_t _matrix_scan(void)
{
    int offset = isLeftHand ? 0 : (ROWS_PER_HAND);
#if (DIODE_DIRECTION == COL2ROW)
    // Set row, read cols
    for (uint8_t current_row = 0; current_row < ROWS_PER_HAND; current_row++) {
#       if (DEBOUNCING_DELAY > 0)
            bool matrix_changed = read_cols_on_row(matrix_debouncing+offset, current_row);

            if (matrix_changed) {
                debouncing = true;
                debouncing_time = timer_read();
                PORTD ^= (1 << 2);
            }

#       else
            read_cols_on_row(matrix+offset, current_row);
#       endif

    }

#elif (DIODE_DIRECTION == ROW2COL)
    // Set col, read rows
    for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
#       if (DEBOUNCING_DELAY > 0)
            bool matrix_changed = read_rows_on_col(matrix_debouncing+offset, current_col);
            if (matrix_changed) {
                debouncing = true;
                debouncing_time = timer_read();
            }
#       else
             read_rows_on_col(matrix+offset, current_col);
#       endif

    }
#endif

#   if (DEBOUNCING_DELAY > 0)
        if (debouncing && (timer_elapsed(debouncing_time) > DEBOUNCING_DELAY)) {
            for (uint8_t i = 0; i < ROWS_PER_HAND; i++) {
                matrix[i+offset] = matrix_debouncing[i+offset];
            }
            debouncing = false;
        }
#   endif

    return 1;
}

#ifdef USE_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(void) {
    int slaveOffset = (isLeftHand) ? (ROWS_PER_HAND) : 0;

    if (serial_update_buffers()) {
        return 1;
    }

    for (int i = 0; i < ROWS_PER_HAND; ++i) {
        matrix[slaveOffset+i] = serial_slave_buffer[i];
    }
    return 0;
}
#endif

uint8_t matrix_scan(void)
{
    uint8_t ret = _matrix_scan();

#ifdef USE_I2C
    if( i2c_transaction() ) {
#else // USE_SERIAL
    if( serial_transaction() ) {
#endif
        // turn on the indicator led when halves are disconnected
        TXLED1;

        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
        TXLED0;
        error_count = 0;
    }
    matrix_scan_quantum();
    return ret;
}

void matrix_slave_scan(void) {
    _matrix_scan();

    int offset = (isLeftHand) ? 0 : ROWS_PER_HAND;

#ifdef USE_I2C
    for (int i = 0; i < ROWS_PER_HAND; ++i) {
        i2c_slave_buffer[i] = matrix[offset+i];
    }
#else // USE_SERIAL
    for (int i = 0; i < ROWS_PER_HAND; ++i) {
        serial_slave_buffer[i] = matrix[offset+i];
    }
#endif
}

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++) {
        phex(row); print(": ");
        pbin_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;
}

#if (DIODE_DIRECTION == COL2ROW)

static void init_cols(void)
{
    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
        uint8_t pin = col_pins[x];
        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
    }
}

static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row)
{
    // Store last value of row prior to reading
    matrix_row_t last_row_value = current_matrix[current_row];

    // Clear data in matrix row
    current_matrix[current_row] = 0;

    // Select row and wait for row selecton to stabilize
    select_row(current_row);
    wait_us(30);

    // For each col...
    for(uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++) {

        // Select the col pin to read (active low)
        uint8_t pin = col_pins[col_index];
        uint8_t pin_state = (_SFR_IO8(pin >> 4) & _BV(pin & 0xF));

        // Populate the matrix row with the state of the col pin
        current_matrix[current_row] |=  pin_state ? 0 : (ROW_SHIFTER << col_index);
    }

    // Unselect row
    unselect_row(current_row);

    return (last_row_value != current_matrix[current_row]);
}

static void select_row(uint8_t row)
{
    uint8_t pin = row_pins[row];
    _SFR_IO8((pin >> 4) + 1) |=  _BV(pin & 0xF); // OUT
    _SFR_IO8((pin >> 4) + 2) &= ~_BV(pin & 0xF); // LOW
}

static void unselect_row(uint8_t row)
{
    uint8_t pin = row_pins[row];
    _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
    _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
}

static void unselect_rows(void)
{
    for(uint8_t x = 0; x < ROWS_PER_HAND; x++) {
        uint8_t pin = row_pins[x];
        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
    }
}

#elif (DIODE_DIRECTION == ROW2COL)

static void init_rows(void)
{
    for(uint8_t x = 0; x < ROWS_PER_HAND; x++) {
        uint8_t pin = row_pins[x];
        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
    }
}

static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col)
{
    bool matrix_changed = false;

    // Select col and wait for col selecton to stabilize
    select_col(current_col);
    wait_us(30);

    // For each row...
    for(uint8_t row_index = 0; row_index < ROWS_PER_HAND; row_index++)
    {

        // Store last value of row prior to reading
        matrix_row_t last_row_value = current_matrix[row_index];

        // Check row pin state
        if ((_SFR_IO8(row_pins[row_index] >> 4) & _BV(row_pins[row_index] & 0xF)) == 0)
        {
            // Pin LO, set col bit
            current_matrix[row_index] |= (ROW_SHIFTER << current_col);
        }
        else
        {
            // Pin HI, clear col bit
            current_matrix[row_index] &= ~(ROW_SHIFTER << current_col);
        }

        // Determine if the matrix changed state
        if ((last_row_value != current_matrix[row_index]) && !(matrix_changed))
        {
            matrix_changed = true;
        }
    }

    // Unselect col
    unselect_col(current_col);

    return matrix_changed;
}

static void select_col(uint8_t col)
{
    uint8_t pin = col_pins[col];
    _SFR_IO8((pin >> 4) + 1) |=  _BV(pin & 0xF); // OUT
    _SFR_IO8((pin >> 4) + 2) &= ~_BV(pin & 0xF); // LOW
}

static void unselect_col(uint8_t col)
{
    uint8_t pin = col_pins[col];
    _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
    _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
}

static void unselect_cols(void)
{
    for(uint8_t x = 0; x < MATRIX_COLS; x++) {
        uint8_t pin = col_pins[x];
        _SFR_IO8((pin >> 4) + 1) &= ~_BV(pin & 0xF); // IN
        _SFR_IO8((pin >> 4) + 2) |=  _BV(pin & 0xF); // HI
    }
}

#endif

A keyboards/ergodash/readme.md => keyboards/ergodash/readme.md +13 -0
@@ 0,0 1,13 @@
# ErgoDash

![ErgoDash](https://i.imgur.com/ZyI592o.jpg)

Keyboard Maintainer: [omkbd](https://github.com/omkbd) [@omkbd](https://twitter.com/omkbd)  
Hardware Supported: ErgoDash PCB, Pro Micro ATmega32u4  
Hardware Availability: In preparation

Make example for this keyboard (after setting up your build environment):

    make ergodash/rev1:default

See [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) then the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information.

A keyboards/ergodash/rev1/config.h => keyboards/ergodash/rev1/config.h +90 -0
@@ 0,0 1,90 @@
/*
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/>.
*/

#ifndef REV1_CONFIG_H
#define REV1_CONFIG_H

#include "config_common.h"

/* USB Device descriptor parameter */
#define VENDOR_ID       0xFEED
#define PRODUCT_ID      0x6060
#define DEVICE_VER      0x0100
#define MANUFACTURER    Omkbd
#define PRODUCT         ErgoDash
#define DESCRIPTION     Power

/* key matrix size */
// Rows are doubled-up
#define MATRIX_ROWS 10
#define MATRIX_COLS 7

// wiring of each half
#define MATRIX_ROW_PINS { D7, E6, B4, B5, D4 }
#define MATRIX_COL_PINS { F5, F6, F7, B1, B3, B2, B6 }
// #define MATRIX_COL_PINS { B6, B2, B3, B1, F7, F6 } //uncomment this line and comment line above if you need to reverse left-to-right key order

/* define tapping term */
#define TAPPING_TERM 120

/* 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 24    // 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

A keyboards/ergodash/rev1/rev1.c => keyboards/ergodash/rev1/rev1.c +39 -0
@@ 0,0 1,39 @@
#include "ergodash.h"

#ifdef AUDIO_ENABLE
    float tone_startup[][2] = SONG(STARTUP_SOUND);
    float tone_goodbye[][2] = SONG(GOODBYE_SOUND);
#endif

#ifdef SSD1306OLED
void led_set_kb(uint8_t usb_led) {
    // put your keyboard LED indicator (ex: Caps Lock LED) toggling code here
    led_set_user(usb_led);
}
#endif

void matrix_init_kb(void) {

    #ifdef AUDIO_ENABLE
        _delay_ms(20); // gets rid of tick
        PLAY_SONG(tone_startup);
    #endif

    // // green led on
    // DDRD |= (1<<5);
    // PORTD &= ~(1<<5);

    // // orange led on
    // DDRB |= (1<<0);
    // PORTB &= ~(1<<0);

	matrix_init_user();
};

void shutdown_user(void) {
    #ifdef AUDIO_ENABLE
        PLAY_SONG(tone_goodbye);
	_delay_ms(150);
	stop_all_notes();
    #endif
}

A keyboards/ergodash/rev1/rev1.h => keyboards/ergodash/rev1/rev1.h +66 -0
@@ 0,0 1,66 @@
#ifndef REV1_H
#define REV1_H

#include "ergodash.h"

//void promicro_bootloader_jmp(bool program);
#include "quantum.h"


#ifdef USE_I2C
#include <stddef.h>
#ifdef __AVR__
	#include <avr/io.h>
	#include <avr/interrupt.h>
#endif
#endif

//void promicro_bootloader_jmp(bool program);

#ifndef FLIP_HALF
// Standard Keymap
// (TRRS jack on the left half is to the right, TRRS jack on the right half is to the left)
#define LAYOUT( \
	L00, L01, L02, L03, L04, L05, L06, R00, R01, R02, R03, R04, R05, R06, \
	L10, L11, L12, L13, L14, L15, L16, R10, R11, R12, R13, R14, R15, R16, \
	L20, L21, L22, L23, L24, L25, L26, R20, R21, R22, R23, R24, R25, R26, \
	L30, L31, L32, L33, L34, L35, L36, R30, R31, R32, R33, R34, R35, R36, \
	LT0, LT1, LT2, LT3,      LT4, LT5, RT0, RT1,      RT2, RT3, RT4, RT5  \
	) \
	{ \
		{ L00, L01, L02, L03, L04, L05, L06 }, \
		{ L10, L11, L12, L13, L14, L15, L16 }, \
		{ L20, L21, L22, L23, L24, L25, L26 }, \
		{ L30, L31, L32, L33, L34, L35, L36 }, \
		{ LT0, LT1, LT2, LT3, LT4, LT5, KC_NO}, \
		{ R06, R05, R04, R03, R02, R01, R00 }, \
		{ R16, R15, R14, R13, R12, R11, R10 }, \
		{ R26, R25, R24, R23, R22, R21, R20 }, \
		{ R36, R35, R34, R33, R32, R31, R30 }, \
		{ RT5, RT4, RT3, RT2, RT1, RT0, KC_NO} \
	}
#else
// Keymap with right side flipped
// (TRRS jack on both halves are to the right)
#define LAYOUT( \
	L00, L01, L02, L03, L04, L05, L06, R00, R01, R02, R03, R04, R05, R06, \
	L10, L11, L12, L13, L14, L15, L16, R10, R11, R12, R13, R14, R15, R16, \
	L20, L21, L22, L23, L24, L25, L26, R20, R21, R22, R23, R24, R25, R26, \
	L30, L31, L32, L33, L34, L35, L36, R30, R31, R32, R33, R34, R35, R36, \
	LT0, LT1, LT2, LT3,      LT4, LT5, RT0, RT1,      RT2, RT3, RT4, RT5  \
	) \
	{ \
		{ L00, L01, L02, L03, L04, L05, L06 }, \
		{ L10, L11, L12, L13, L14, L15, L16 }, \
		{ L20, L21, L22, L23, L24, L25, L26 }, \
		{ L30, L31, L32, L33, L34, L35, L36 }, \
		{ LT0, LT1, LT2, LT3, LT4, LT, KC_NO}, \
		{ R00, R01, R02, R03, R04, R05, R06 }, \
		{ R10, R11, R12, R13, R14, R15, R16 }, \
		{ R20, R21, R22, R23, R24, R25, R26 }, \
		{ R30, R31, R32, R33, R34, R35, R36 }, \
		{ RT0, RT1, RT2, RT3, RT4, RT5, KC_NO} \
	}
#endif

#endif

A keyboards/ergodash/rev1/rules.mk => keyboards/ergodash/rev1/rules.mk +1 -0
@@ 0,0 1,1 @@
BACKLIGHT_ENABLE = no

A keyboards/ergodash/rules.mk => keyboards/ergodash/rules.mk +77 -0
@@ 0,0 1,77 @@
SRC += matrix.c \
	   i2c.c \
	   split_util.c \
	   serial.c \
	   ssd1306.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

# Bootloader
#     This definition is optional, and if your keyboard supports multiple bootloaders of
#     different sizes, comment this out, and the correct address will be loaded
#     automatically (+60). See bootloader.mk for all options.
BOOTLOADER = caterina

# 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 = no       # 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 = yes       # 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

LAYOUTS = ortho_5x14

DEFAULT_FOLDER = ergodash/rev1

A keyboards/ergodash/serial.c => keyboards/ergodash/serial.c +228 -0
@@ 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"

#ifndef USE_I2C

// 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

A keyboards/ergodash/serial.h => keyboards/ergodash/serial.h +26 -0
@@ 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_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

A keyboards/ergodash/split_util.c => keyboards/ergodash/split_util.c +86 -0
@@ 0,0 1,86 @@
#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"
#include "timer.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();
#ifdef SSD1306OLED
    matrix_master_OLED_init ();
#endif
#else
    serial_master_init();
#endif
}

static void keyboard_slave_setup(void) {
  timer_init();
#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();
    }
}

A keyboards/ergodash/split_util.h => keyboards/ergodash/split_util.h +20 -0
@@ 0,0 1,20 @@
#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
void matrix_slave_scan(void);

void split_keyboard_setup(void);
bool has_usb(void);
void keyboard_slave_loop(void);

void matrix_master_OLED_init (void);

#endif