Creates a layouts/ folder for keymaps shared between keyboards (#1609)

* include variables and .h files as pp directives

* start layout compilation

* split ergodoxes up

* don't compile all layouts for everything

* might seg fault

* reset layouts variable

* actually reset layouts

* include rules.mk instead

* remove includes from rules.mk

* update variable setting

* load visualizer from path

* adds some more examples

* adds more layouts

* more boards added

* more boards added

* adds documentation for layouts

* use lowercase names for LAYOUT_

* add layout.json files for each layout

* add community folder, default keymaps for layouts

* touch-up default layouts

* touch-up layouts, some keyboard rules.mk

* update documentation for layouts

* fix up serial/i2c switches

13 files changed, 1359 insertions, 0 deletions

diff --git a/keyboards/ergodone/Makefile b/keyboards/ergodone/Makefile
new file mode 100644
index 000000000..bd09e5885
--- /dev/null
+++ b/keyboards/ergodone/Makefile
@@ -0,0 +1,3 @@
+ifndef MAKEFILE_INCLUDED
+        include ../../../Makefile
+endif
diff --git a/keyboards/ergodone/config.h b/keyboards/ergodone/config.h
new file mode 100644
index 000000000..d3e0f8036
--- /dev/null
+++ b/keyboards/ergodone/config.h
@@ -0,0 +1,78 @@
+#ifndef ERGODOX_ERGODONE_CONFIG_H
+#define ERGODOX_ERGODONE_CONFIG_H
+
+#include "config_common.h"
+
+/* USB Device descriptor parameter */
+#define VENDOR_ID       0xFEED
+#define PRODUCT_ID      0x1307
+#define DEVICE_VER      0x0001
+#define MANUFACTURER    ErgoDone
+#define PRODUCT         ErgoDone
+#define DESCRIPTION     QMK keyboard firmware for ErgoDone
+
+/* key matrix size */
+#define MATRIX_ROWS 6
+#define MATRIX_COLS 14
+
+#define MOUSEKEY_INTERVAL       20
+#define MOUSEKEY_DELAY          0
+#define MOUSEKEY_TIME_TO_MAX    60
+#define MOUSEKEY_MAX_SPEED      7
+#define MOUSEKEY_WHEEL_DELAY 0
+
+#define TAPPING_TOGGLE  1
+
+/* define if matrix has ghost */
+//#define MATRIX_HAS_GHOST
+
+#define TAPPING_TERM    200
+#define IGNORE_MOD_TAP_INTERRUPT // this makes it possible to do rolling combos (zx) with keys that convert to other keys on hold (z becomes ctrl when you hold it, and when this option isn't enabled, z rapidly followed by x actually sends Ctrl-x. That's bad.)
+
+/* 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_LCTL) | MOD_BIT(KC_RCTL)) || \
+    keyboard_report->mods == (MOD_BIT(KC_LSFT) | MOD_BIT(KC_RSFT)) \
+)
+
+/* number of backlight levels */
+#define BACKLIGHT_LEVELS 3
+
+#define LED_BRIGHTNESS_LO       15
+#define LED_BRIGHTNESS_HI       255
+
+/* fix space cadet rollover issue */
+#define DISABLE_SPACE_CADET_ROLLOVER
+
+/* Set 0 if debouncing isn't needed */
+#define DEBOUNCE    5
+
+#define PREVENT_STUCK_MODIFIERS
+
+#define USB_MAX_POWER_CONSUMPTION 500
+
+/*
+ * 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
+//#define DEBUG_MATRIX_SCAN_RATE
+
+#endif
diff --git a/keyboards/ergodone/ergodone.c b/keyboards/ergodone/ergodone.c
new file mode 100644
index 000000000..6b8d8a063
--- /dev/null
+++ b/keyboards/ergodone/ergodone.c
@@ -0,0 +1,5 @@
+#include "ergodone.h"
+
+void matrix_init_kb(void) {
+  matrix_init_user();
+}
diff --git a/keyboards/ergodone/ergodone.h b/keyboards/ergodone/ergodone.h
new file mode 100644
index 000000000..9f6c8f841
--- /dev/null
+++ b/keyboards/ergodone/ergodone.h
@@ -0,0 +1,65 @@
+#ifndef ERGODOX_ERGODONE_H
+#define ERGODOX_ERGODONE_H
+
+#include "quantum.h"
+#include <stdint.h>
+#include <stdbool.h>
+
+#define CPU_PRESCALE(n) (CLKPR = 0x80, CLKPR = (n))
+#define CPU_16MHz       0x00
+
+void init_ergodox(void);
+
+inline void ergodox_right_led_1_off(void)               {}
+inline void ergodox_right_led_1_on(void)                {}
+inline void ergodox_right_led_2_off(void)               {}
+inline void ergodox_right_led_2_on(void)                {}
+inline void ergodox_right_led_3_off(void)               {}
+inline void ergodox_right_led_3_on(void)                {}
+inline void ergodox_right_led_on(uint8_t l)             {}
+inline void ergodox_right_led_off(uint8_t l)            {}
+inline void ergodox_board_led_off(void)                 {}
+inline void ergodox_board_led_on(void)                  {}
+inline void ergodox_led_all_on(void)                    {}
+inline void ergodox_led_all_off(void)                   {}
+inline void ergodox_right_led_1_set(uint8_t n)          {}
+inline void ergodox_right_led_2_set(uint8_t n)          {}
+inline void ergodox_right_led_3_set(uint8_t n)          {}
+inline void ergodox_right_led_set(uint8_t l, uint8_t n) {}
+inline void ergodox_led_all_set(uint8_t n)              {}
+
+#define KEYMAP(                                                 \
+                                                                \
+    /* left hand, spatial positions */                          \
+    k00,k01,k02,k03,k04,k05,k06,                                \
+    k10,k11,k12,k13,k14,k15,k16,                                \
+    k20,k21,k22,k23,k24,k25,                                    \
+    k30,k31,k32,k33,k34,k35,k36,                                \
+    k40,k41,k42,k43,k44,                                        \
+                            k55,k56,                            \
+                                k54,                            \
+                        k53,k52,k51,                            \
+                                                                \
+    /* right hand, spatial positions */                         \
+        k07,k08,k09,k0A,k0B,k0C,k0D,                            \
+        k17,k18,k19,k1A,k1B,k1C,k1D,                            \
+            k28,k29,k2A,k2B,k2C,k2D,                            \
+        k37,k38,k39,k3A,k3B,k3C,k3D,                            \
+                k49,k4A,k4B,k4C,k4D,                            \
+    k57,k58,                                                    \
+    k59,                                                        \
+    k5C,k5B,k5A )                                               \
+                                                                \
+   /* matrix positions */                                       \
+   {                                                            \
+    { k00,   k01, k02, k03, k04, k05,   k06,      k07,   k08,   k09, k0A, k0B, k0C, k0D    }, \
+    { k10,   k11, k12, k13, k14, k15,   k16,      k17,   k18,   k19, k1A, k1B, k1C, k1D    }, \
+    { k20,   k21, k22, k23, k24, k25,   KC_NO,    KC_NO, k28,   k29, k2A, k2B, k2C, k2D    }, \
+    { k30,   k31, k32, k33, k34, k35,   k36,      k37,   k38,   k39, k3A, k3B, k3C, k3D    }, \
+    { k40,   k41, k42, k43, k44, KC_NO, KC_NO,    KC_NO, KC_NO, k49, k4A, k4B, k4C, k4D    }, \
+    { KC_NO, k51, k52, k53, k54, k55,   k56,      k57,   k58,   k59, k5A, k5B, k5C, KC_NO  } \
+   }
+
+#define LAYOUT_ergodox KEYMAP
+
+#endif
diff --git a/keyboards/ergodone/expander.c b/keyboards/ergodone/expander.c
new file mode 100644
index 000000000..0c8a2289c
--- /dev/null
+++ b/keyboards/ergodone/expander.c
@@ -0,0 +1,120 @@
+#include <stdbool.h>
+#include "action.h"
+#include "i2cmaster.h"
+#include "expander.h"
+#include "debug.h"
+
+static uint8_t expander_status = 0;
+static uint8_t expander_input = 0;
+
+void expander_config(void);
+uint8_t expander_write(uint8_t reg, uint8_t data);
+uint8_t expander_read(uint8_t reg, uint8_t *data);
+
+void expander_init(void)
+{
+  i2c_init();
+  expander_scan();
+}
+
+void expander_scan(void)
+{
+  dprintf("expander status: %d ... ", expander_status);
+  uint8_t ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
+  if (ret == 0) {
+    i2c_stop();
+    if (expander_status == 0) {
+      dprintf("attached\n");
+      expander_status = 1;
+      expander_config();
+      clear_keyboard();
+    }
+  }
+  else {
+    if (expander_status == 1) {
+      dprintf("detached\n");
+      expander_status = 0;
+      clear_keyboard();
+    }
+  }
+  dprintf("%d\n", expander_status);
+}
+
+void expander_read_cols(void)
+{
+  expander_read(EXPANDER_REG_GPIOA, &expander_input);
+}
+
+uint8_t expander_get_col(uint8_t col)
+{
+  if (col > 4) {
+    col++;
+  }
+  return expander_input & (1<<col) ? 1 : 0;
+}
+
+matrix_row_t expander_read_row(void)
+{
+  expander_read_cols();
+
+  /* make cols */
+  matrix_row_t cols = 0;
+  for (uint8_t col = 0; col < MATRIX_COLS; col++) {
+    if (expander_get_col(col)) {
+      cols |= (1UL << (MATRIX_COLS - 1 - col));
+    }
+  }
+
+  return cols;
+}
+
+void expander_unselect_rows(void)
+{
+  expander_write(EXPANDER_REG_IODIRB, 0xFF);
+}
+
+void expander_select_row(uint8_t row)
+{
+  expander_write(EXPANDER_REG_IODIRB, ~(1<<(row+1)));
+}
+
+void expander_config(void)
+{
+  expander_write(EXPANDER_REG_IPOLA, 0xFF);
+  expander_write(EXPANDER_REG_GPPUA, 0xFF);
+  expander_write(EXPANDER_REG_IODIRB, 0xFF);
+}
+
+uint8_t expander_write(uint8_t reg, uint8_t data)
+{
+  if (expander_status == 0) {
+    return 0;
+  }
+  uint8_t ret;
+  ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
+  if (ret) goto stop;
+  ret = i2c_write(reg);
+  if (ret) goto stop;
+  ret = i2c_write(data);
+ stop:
+  i2c_stop();
+  return ret;
+}
+
+uint8_t expander_read(uint8_t reg, uint8_t *data)
+{
+  if (expander_status == 0) {
+    return 0;
+  }
+  uint8_t ret;
+  ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
+  if (ret) goto stop;
+  ret = i2c_write(reg);
+  if (ret) goto stop;
+  ret = i2c_rep_start(EXPANDER_ADDR | I2C_READ);
+  if (ret) goto stop;
+  *data = i2c_readNak();
+ stop:
+  i2c_stop();
+  return ret;
+}
diff --git a/keyboards/ergodone/expander.h b/keyboards/ergodone/expander.h
new file mode 100644
index 000000000..8676fed69
--- /dev/null
+++ b/keyboards/ergodone/expander.h
@@ -0,0 +1,48 @@
+#ifndef EXPANDER_H
+#define EXPANDER_H
+
+#include <stdint.h>
+#include "matrix.h"
+
+#define MCP23017
+#define MCP23017_A0 0
+#define MCP23017_A1 0
+#define MCP23017_A2 0
+
+#ifdef MCP23017
+#define EXPANDER_ADDR ((0x20|(MCP23017_A0<<0)|(MCP23017_A1<<1)|(MCP23017_A2<<2)) << 1)
+enum EXPANDER_REG_BANK0 {
+  EXPANDER_REG_IODIRA = 0,
+  EXPANDER_REG_IODIRB,
+  EXPANDER_REG_IPOLA,
+  EXPANDER_REG_IPOLB,
+  EXPANDER_REG_GPINTENA,
+  EXPANDER_REG_GPINTENB,
+  EXPANDER_REG_DEFVALA,
+  EXPANDER_REG_DEFVALB,
+  EXPANDER_REG_INTCONA,
+  EXPANDER_REG_INTCONB,
+  EXPANDER_REG_IOCONA,
+  EXPANDER_REG_IOCONB,
+  EXPANDER_REG_GPPUA,
+  EXPANDER_REG_GPPUB,
+  EXPANDER_REG_INTFA,
+  EXPANDER_REG_INTFB,
+  EXPANDER_REG_INTCAPA,
+  EXPANDER_REG_INTCAPB,
+  EXPANDER_REG_GPIOA,
+  EXPANDER_REG_GPIOB,
+  EXPANDER_REG_OLATA,
+  EXPANDER_REG_OLATB
+};
+#endif
+
+void expander_init(void);
+void expander_scan(void);
+void expander_read_cols(void);
+uint8_t expander_get_col(uint8_t col);
+matrix_row_t expander_read_row(void);
+void expander_unselect_rows(void);
+void expander_select_row(uint8_t row);
+
+#endif
diff --git a/keyboards/ergodone/i2cmaster.h b/keyboards/ergodone/i2cmaster.h
new file mode 100644
index 000000000..3917b9e6c
--- /dev/null
+++ b/keyboards/ergodone/i2cmaster.h
@@ -0,0 +1,178 @@
+#ifndef _I2CMASTER_H
+#define _I2CMASTER_H   1
+/************************************************************************* 
+* Title:    C include file for the I2C master interface 
+*           (i2cmaster.S or twimaster.c)
+* Author:   Peter Fleury <pfleury@gmx.ch>  http://jump.to/fleury
+* File:     $Id: i2cmaster.h,v 1.10 2005/03/06 22:39:57 Peter Exp $
+* Software: AVR-GCC 3.4.3 / avr-libc 1.2.3
+* Target:   any AVR device
+* Usage:    see Doxygen manual
+**************************************************************************/
+
+#ifdef DOXYGEN
+/**
+ @defgroup pfleury_ic2master I2C Master library
+ @code #include <i2cmaster.h> @endcode
+  
+ @brief I2C (TWI) Master Software Library
+
+ Basic routines for communicating with I2C slave devices. This single master 
+ implementation is limited to one bus master on the I2C bus. 
+
+ This I2c library is implemented as a compact assembler software implementation of the I2C protocol 
+ which runs on any AVR (i2cmaster.S) and as a TWI hardware interface for all AVR with built-in TWI hardware (twimaster.c).
+ Since the API for these two implementations is exactly the same, an application can be linked either against the
+ software I2C implementation or the hardware I2C implementation.
+
+ Use 4.7k pull-up resistor on the SDA and SCL pin.
+ 
+ Adapt the SCL and SDA port and pin definitions and eventually the delay routine in the module 
+ i2cmaster.S to your target when using the software I2C implementation ! 
+ 
+ Adjust the  CPU clock frequence F_CPU in twimaster.c or in the Makfile when using the TWI hardware implementaion.
+
+ @note 
+    The module i2cmaster.S is based on the Atmel Application Note AVR300, corrected and adapted 
+    to GNU assembler and AVR-GCC C call interface.
+    Replaced the incorrect quarter period delays found in AVR300 with 
+    half period delays. 
+    
+ @author Peter Fleury pfleury@gmx.ch  http://jump.to/fleury
+
+ @par API Usage Example
+  The following code shows typical usage of this library, see example test_i2cmaster.c
+
+ @code
+
+ #include <i2cmaster.h>
+
+
+ #define Dev24C02  0xA2      // device address of EEPROM 24C02, see datasheet
+
+ int main(void)
+ {
+     unsigned char ret;
+
+     i2c_init();                             // initialize I2C library
+
+     // write 0x75 to EEPROM address 5 (Byte Write) 
+     i2c_start_wait(Dev24C02+I2C_WRITE);     // set device address and write mode
+     i2c_write(0x05);                        // write address = 5
+     i2c_write(0x75);                        // write value 0x75 to EEPROM
+     i2c_stop();                             // set stop conditon = release bus
+
+
+     // read previously written value back from EEPROM address 5 
+     i2c_start_wait(Dev24C02+I2C_WRITE);     // set device address and write mode
+
+     i2c_write(0x05);                        // write address = 5
+     i2c_rep_start(Dev24C02+I2C_READ);       // set device address and read mode
+
+     ret = i2c_readNak();                    // read one byte from EEPROM
+     i2c_stop();
+
+     for(;;);
+ }
+ @endcode
+
+*/
+#endif /* DOXYGEN */
+
+/**@{*/
+
+#if (__GNUC__ * 100 + __GNUC_MINOR__) < 304
+#error "This library requires AVR-GCC 3.4 or later, update to newer AVR-GCC compiler !"
+#endif
+
+#include <avr/io.h>
+
+/** defines the data direction (reading from I2C device) in i2c_start(),i2c_rep_start() */
+#define I2C_READ    1
+
+/** defines the data direction (writing to I2C device) in i2c_start(),i2c_rep_start() */
+#define I2C_WRITE   0
+
+
+/**
+ @brief initialize the I2C master interace. Need to be called only once 
+ @param  void
+ @return none
+ */
+extern void i2c_init(void);
+
+
+/** 
+ @brief Terminates the data transfer and releases the I2C bus 
+ @param void
+ @return none
+ */
+extern void i2c_stop(void);
+
+
+/** 
+ @brief Issues a start condition and sends address and transfer direction 
+  
+ @param    addr address and transfer direction of I2C device
+ @retval   0   device accessible 
+ @retval   1   failed to access device 
+ */
+extern unsigned char i2c_start(unsigned char addr);
+
+
+/**
+ @brief Issues a repeated start condition and sends address and transfer direction 
+
+ @param   addr address and transfer direction of I2C device
+ @retval  0 device accessible
+ @retval  1 failed to access device
+ */
+extern unsigned char i2c_rep_start(unsigned char addr);
+
+
+/**
+ @brief Issues a start condition and sends address and transfer direction 
+   
+ If device is busy, use ack polling to wait until device ready 
+ @param    addr address and transfer direction of I2C device
+ @return   none
+ */
+extern void i2c_start_wait(unsigned char addr);
+
+ 
+/**
+ @brief Send one byte to I2C device
+ @param    data  byte to be transfered
+ @retval   0 write successful
+ @retval   1 write failed
+ */
+extern unsigned char i2c_write(unsigned char data);
+
+
+/**
+ @brief    read one byte from the I2C device, request more data from device 
+ @return   byte read from I2C device
+ */
+extern unsigned char i2c_readAck(void);
+
+/**
+ @brief    read one byte from the I2C device, read is followed by a stop condition 
+ @return   byte read from I2C device
+ */
+extern unsigned char i2c_readNak(void);
+
+/** 
+ @brief    read one byte from the I2C device
+ 
+ Implemented as a macro, which calls either i2c_readAck or i2c_readNak
+ 
+ @param    ack 1 send ack, request more data from device<br>
+               0 send nak, read is followed by a stop condition 
+ @return   byte read from I2C device
+ */
+extern unsigned char i2c_read(unsigned char ack);
+#define i2c_read(ack)  (ack) ? i2c_readAck() : i2c_readNak(); 
+
+
+/**@}*/
+#endif
diff --git a/keyboards/ergodone/keymaps/default/keymap.c b/keyboards/ergodone/keymaps/default/keymap.c
new file mode 100644
index 000000000..cbc180d6a
--- /dev/null
+++ b/keyboards/ergodone/keymaps/default/keymap.c
@@ -0,0 +1,223 @@
+#include QMK_KEYBOARD_H
+#include "debug.h"
+#include "action_layer.h"
+#include "version.h"
+
+#define BASE 0 // default layer
+#define SYMB 1 // symbols
+#define MDIA 2 // media keys
+
+enum custom_keycodes {
+  PLACEHOLDER = SAFE_RANGE, // can always be here
+  EPRM,
+  VRSN,
+  RGB_SLD
+};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+/* Keymap 0: Basic layer
+ *
+ * ,--------------------------------------------------.           ,--------------------------------------------------.
+ * |   =    |   1  |   2  |   3  |   4  |   5  | LEFT |           | RIGHT|   6  |   7  |   8  |   9  |   0  |   -    |
+ * |--------+------+------+------+------+-------------|           |------+------+------+------+------+------+--------|
+ * | Del    |   Q  |   W  |   E  |   R  |   T  |  L1  |           |  L1  |   Y  |   U  |   I  |   O  |   P  |   \    |
+ * |--------+------+------+------+------+------|      |           |      |------+------+------+------+------+--------|
+ * | BkSp   |   A  |   S  |   D  |   F  |   G  |------|           |------|   H  |   J  |   K  |   L  |; / L2|' / Cmd |
+ * |--------+------+------+------+------+------| Hyper|           | Meh  |------+------+------+------+------+--------|
+ * | LShift |Z/Ctrl|   X  |   C  |   V  |   B  |      |           |      |   N  |   M  |   ,  |   .  |//Ctrl| RShift |
+ * `--------+------+------+------+------+-------------'           `-------------+------+------+------+------+--------'
+ *   |Grv/L1|  '"  |AltShf| Left | Right|                                       |  Up  | Down |   [  |   ]  | ~L1  |
+ *   `----------------------------------'                                       `----------------------------------'
+ *                                        ,-------------.       ,-------------.
+ *                                        | App  | LGui |       | Alt  |Ctrl/Esc|
+ *                                 ,------|------|------|       |------+--------+------.
+ *                                 |      |      | Home |       | PgUp |        |      |
+ *                                 | Space|Backsp|------|       |------|  Tab   |Enter |
+ *                                 |      |ace   | End  |       | PgDn |        |      |
+ *                                 `--------------------'       `----------------------'
+ */
+// If it accepts an argument (i.e, is a function), it doesn't need KC_.
+// Otherwise, it needs KC_*
+[BASE] = LAYOUT_ergodox(  // layer 0 : default
+        // left hand
+        KC_EQL,         KC_1,         KC_2,   KC_3,   KC_4,   KC_5,   KC_LEFT,
+        KC_DELT,        KC_Q,         KC_W,   KC_E,   KC_R,   KC_T,   TG(SYMB),
+        KC_BSPC,        KC_A,         KC_S,   KC_D,   KC_F,   KC_G,
+        KC_LSFT,        CTL_T(KC_Z),  KC_X,   KC_C,   KC_V,   KC_B,   ALL_T(KC_NO),
+        LT(SYMB,KC_GRV),KC_QUOT,      LALT(KC_LSFT),  KC_LEFT,KC_RGHT,
+                                              ALT_T(KC_APP),  KC_LGUI,
+                                                              KC_HOME,
+                                               KC_SPC,KC_BSPC,KC_END,
+        // right hand
+             KC_RGHT,     KC_6,   KC_7,  KC_8,   KC_9,   KC_0,             KC_MINS,
+             TG(SYMB),    KC_Y,   KC_U,  KC_I,   KC_O,   KC_P,             KC_BSLS,
+                          KC_H,   KC_J,  KC_K,   KC_L,   LT(MDIA, KC_SCLN),GUI_T(KC_QUOT),
+             MEH_T(KC_NO),KC_N,   KC_M,  KC_COMM,KC_DOT, CTL_T(KC_SLSH),   KC_RSFT,
+                                  KC_UP, KC_DOWN,KC_LBRC,KC_RBRC,          KC_FN1,
+             KC_LALT,        CTL_T(KC_ESC),
+             KC_PGUP,
+             KC_PGDN,KC_TAB, KC_ENT
+    ),
+/* Keymap 1: Symbol Layer
+ *
+ * ,---------------------------------------------------.           ,--------------------------------------------------.
+ * |Version  |  F1  |  F2  |  F3  |  F4  |  F5  |      |           |      |  F6  |  F7  |  F8  |  F9  |  F10 |   F11  |
+ * |---------+------+------+------+------+------+------|           |------+------+------+------+------+------+--------|
+ * |         |   !  |   @  |   {  |   }  |   |  |      |           |      |   Up |   7  |   8  |   9  |   *  |   F12  |
+ * |---------+------+------+------+------+------|      |           |      |------+------+------+------+------+--------|
+ * |         |   #  |   $  |   (  |   )  |   `  |------|           |------| Down |   4  |   5  |   6  |   +  |        |
+ * |---------+------+------+------+------+------|      |           |      |------+------+------+------+------+--------|
+ * |         |   %  |   ^  |   [  |   ]  |   ~  |      |           |      |   &  |   1  |   2  |   3  |   \  |        |
+ * `---------+------+------+------+------+-------------'           `-------------+------+------+------+------+--------'
+ *   | EPRM  |      |      |      |      |                                       |      |    . |   0  |   =  |      |
+ *   `-----------------------------------'                                       `----------------------------------'
+ *                                        ,-------------.       ,-------------.
+ *                                        |Animat|      |       |Toggle|Solid |
+ *                                 ,------|------|------|       |------+------+------.
+ *                                 |Bright|Bright|      |       |      |Hue-  |Hue+  |
+ *                                 |ness- |ness+ |------|       |------|      |      |
+ *                                 |      |      |      |       |      |      |      |
+ *                                 `--------------------'       `--------------------'
+ */
+// SYMBOLS
+[SYMB] = LAYOUT_ergodox(
+       // left hand
+       VRSN,   KC_F1,  KC_F2,  KC_F3,  KC_F4,  KC_F5,  KC_TRNS,
+       KC_TRNS,KC_EXLM,KC_AT,  KC_LCBR,KC_RCBR,KC_PIPE,KC_TRNS,
+       KC_TRNS,KC_HASH,KC_DLR, KC_LPRN,KC_RPRN,KC_GRV,
+       KC_TRNS,KC_PERC,KC_CIRC,KC_LBRC,KC_RBRC,KC_TILD,KC_TRNS,
+          EPRM,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,
+                                       RGB_MOD,KC_TRNS,
+                                               KC_TRNS,
+                               RGB_VAD,RGB_VAI,KC_TRNS,
+       // right hand
+       KC_TRNS, KC_F6,   KC_F7,  KC_F8,   KC_F9,   KC_F10,  KC_F11,
+       KC_TRNS, KC_UP,   KC_7,   KC_8,    KC_9,    KC_ASTR, KC_F12,
+                KC_DOWN, KC_4,   KC_5,    KC_6,    KC_PLUS, KC_TRNS,
+       KC_TRNS, KC_AMPR, KC_1,   KC_2,    KC_3,    KC_BSLS, KC_TRNS,
+                         KC_TRNS,KC_DOT,  KC_0,    KC_EQL,  KC_TRNS,
+       RGB_TOG, RGB_SLD,
+       KC_TRNS,
+       KC_TRNS, RGB_HUD, RGB_HUI
+),
+/* Keymap 2: Media and mouse keys
+ *
+ * ,--------------------------------------------------.           ,--------------------------------------------------.
+ * |        |      |      |      |      |      |      |           |      |      |      |      |      |      |        |
+ * |--------+------+------+------+------+-------------|           |------+------+------+------+------+------+--------|
+ * |        |      |      | MsUp |      |      |      |           |      |      |      |      |      |      |        |
+ * |--------+------+------+------+------+------|      |           |      |------+------+------+------+------+--------|
+ * |        |      |MsLeft|MsDown|MsRght|      |------|           |------|      |      |      |      |      |  Play  |
+ * |--------+------+------+------+------+------|      |           |      |------+------+------+------+------+--------|
+ * |        |      |      |      |      |      |      |           |      |      |      | Prev | Next |      |        |
+ * `--------+------+------+------+------+-------------'           `-------------+------+------+------+------+--------'
+ *   |      |      |      | Lclk | Rclk |                                       |VolUp |VolDn | Mute |      |      |
+ *   `----------------------------------'                                       `----------------------------------'
+ *                                        ,-------------.       ,-------------.
+ *                                        |      |      |       |      |      |
+ *                                 ,------|------|------|       |------+------+------.
+ *                                 |      |      |      |       |      |      |Brwser|
+ *                                 |      |      |------|       |------|      |Back  |
+ *                                 |      |      |      |       |      |      |      |
+ *                                 `--------------------'       `--------------------'
+ */
+// MEDIA AND MOUSE
+[MDIA] = LAYOUT_ergodox(
+       KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
+       KC_TRNS, KC_TRNS, KC_TRNS, KC_MS_U, KC_TRNS, KC_TRNS, KC_TRNS,
+       KC_TRNS, KC_TRNS, KC_MS_L, KC_MS_D, KC_MS_R, KC_TRNS,
+       KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
+       KC_TRNS, KC_TRNS, KC_TRNS, KC_BTN1, KC_BTN2,
+                                           KC_TRNS, KC_TRNS,
+                                                    KC_TRNS,
+                                  KC_TRNS, KC_TRNS, KC_TRNS,
+    // right hand
+       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_MPLY,
+       KC_TRNS,  KC_TRNS, KC_TRNS, KC_MPRV, KC_MNXT, KC_TRNS, KC_TRNS,
+                          KC_VOLU, KC_VOLD, KC_MUTE, KC_TRNS, KC_TRNS,
+       KC_TRNS, KC_TRNS,
+       KC_TRNS,
+       KC_TRNS, KC_TRNS, KC_WBAK
+),
+};
+
+const uint16_t PROGMEM fn_actions[] = {
+    [1] = ACTION_LAYER_TAP_TOGGLE(SYMB)                // FN1 - Momentary Layer 1 (Symbols)
+};
+
+const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt)
+{
+  // MACRODOWN only works in this function
+      switch(id) {
+        case 0:
+        if (record->event.pressed) {
+          SEND_STRING (QMK_KEYBOARD "/" QMK_KEYMAP " @ " QMK_VERSION);
+        }
+        break;
+        case 1:
+        if (record->event.pressed) { // For resetting EEPROM
+          eeconfig_init();
+        }
+        break;
+      }
+    return MACRO_NONE;
+};
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+  switch (keycode) {
+    // dynamically generate these.
+    case EPRM:
+      if (record->event.pressed) {
+        eeconfig_init();
+      }
+      return false;
+      break;
+    case VRSN:
+      if (record->event.pressed) {
+        SEND_STRING (QMK_KEYBOARD "/" QMK_KEYMAP " @ " QMK_VERSION);
+      }
+      return false;
+      break;
+    case RGB_SLD:
+      if (record->event.pressed) {
+        #ifdef RGBLIGHT_ENABLE
+          rgblight_mode(1);
+        #endif
+      }
+      return false;
+      break;
+  }
+  return true;
+}
+
+// Runs just one time when the keyboard initializes.
+void matrix_init_user(void) {
+
+};
+
+
+// Runs constantly in the background, in a loop.
+void matrix_scan_user(void) {
+
+    uint8_t layer = biton32(layer_state);
+
+    ergodox_board_led_off();
+    ergodox_right_led_1_off();
+    ergodox_right_led_2_off();
+    ergodox_right_led_3_off();
+    switch (layer) {
+      // TODO: Make this relevant to the ErgoDox EZ.
+        case 1:
+            ergodox_right_led_1_on();
+            break;
+        case 2:
+            ergodox_right_led_2_on();
+            break;
+        default:
+            // none
+            break;
+    }
+
+};
diff --git a/keyboards/ergodone/keymaps/default/readme.md b/keyboards/ergodone/keymaps/default/readme.md
new file mode 100644
index 000000000..1150a4f70
--- /dev/null
+++ b/keyboards/ergodone/keymaps/default/readme.md
@@ -0,0 +1,15 @@
+# ErgoDox EZ Default Configuration
+
+## Changelog
+
+* Dec 2016:
+  * Added LED keys
+  * Refreshed layout graphic, comes from http://configure.ergodox-ez.com now.
+* Sep 22, 2016:
+  * Created a new key in layer 1 (bottom-corner key) that resets the EEPROM.
+* Feb 2, 2016 (V1.1): 
+  * Made the right-hand quote key double as Cmd/Win on hold. So you get ' when you tap it, " when you tap it with Shift, and Cmd or Win when you hold it. You can then use it as a modifier, or just press and hold it for a moment (and then let go) to send a single Cmd or Win keystroke (handy for opening the Start menu on Windows).
+
+This is what we ship with out of the factory. :) The image says it all:
+
+![Default](https://i.imgur.com/Be53jH7.png)
\ No newline at end of file
diff --git a/keyboards/ergodone/matrix.c b/keyboards/ergodone/matrix.c
new file mode 100644
index 000000000..2eb8f24ba
--- /dev/null
+++ b/keyboards/ergodone/matrix.c
@@ -0,0 +1,295 @@
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/io.h>
+#include "wait.h"
+#include "action_layer.h"
+#include "print.h"
+#include "debug.h"
+#include "util.h"
+#include "matrix.h"
+#include "ergodone.h"
+#include "expander.h"
+#ifdef DEBUG_MATRIX_SCAN_RATE
+#include  "timer.h"
+#endif
+
+/*
+ * This constant define not debouncing time in msecs, but amount of matrix
+ * scan loops which should be made to get stable debounced results.
+ *
+ * On Ergodox matrix scan rate is relatively low, because of slow I2C.
+ * Now it's only 317 scans/second, or about 3.15 msec/scan.
+ * According to Cherry specs, debouncing time is 5 msec.
+ *
+ * And so, there is no sense to have DEBOUNCE higher than 2.
+ */
+
+#ifndef DEBOUNCE
+#   define DEBOUNCE     5
+#endif
+
+/* matrix state(1:on, 0:off) */
+static matrix_row_t matrix[MATRIX_ROWS];
+
+// Debouncing: store for each key the number of scans until it's eligible to
+// change.  When scanning the matrix, ignore any changes in keys that have
+// already changed in the last DEBOUNCE scans.
+static uint8_t debounce_matrix[MATRIX_ROWS * MATRIX_COLS];
+
+static matrix_row_t read_cols(uint8_t row);
+static void init_cols(void);
+static void unselect_rows(void);
+static void select_row(uint8_t row);
+
+#ifdef DEBUG_MATRIX_SCAN_RATE
+uint32_t matrix_timer;
+uint32_t matrix_scan_count;
+#endif
+
+
+__attribute__ ((weak))
+void matrix_init_user(void) {}
+
+__attribute__ ((weak))
+void matrix_scan_user(void) {}
+
+__attribute__ ((weak))
+void matrix_init_kb(void) {
+  matrix_init_user();
+}
+
+__attribute__ ((weak))
+void matrix_scan_kb(void) {
+  matrix_scan_user();
+}
+
+inline
+uint8_t matrix_rows(void)
+{
+  return MATRIX_ROWS;
+}
+
+inline
+uint8_t matrix_cols(void)
+{
+  return MATRIX_COLS;
+}
+
+void matrix_init(void)
+{
+  // disable JTAG
+  MCUCR = (1<<JTD);
+  MCUCR = (1<<JTD);
+
+  unselect_rows();
+  init_cols();
+
+  // initialize matrix state: all keys off
+  for (uint8_t i=0; i < MATRIX_ROWS; i++) {
+    matrix[i] = 0;
+    for (uint8_t j=0; j < MATRIX_COLS; ++j) {
+      debounce_matrix[i * MATRIX_COLS + j] = 0;
+    }
+  }
+
+#ifdef DEBUG_MATRIX_SCAN_RATE
+  matrix_timer = timer_read32();
+  matrix_scan_count = 0;
+#endif
+
+  matrix_init_quantum();
+
+}
+
+void matrix_power_up(void) {
+  unselect_rows();
+  init_cols();
+
+  // initialize matrix state: all keys off
+  for (uint8_t i=0; i < MATRIX_ROWS; i++) {
+    matrix[i] = 0;
+  }
+
+#ifdef DEBUG_MATRIX_SCAN_RATE
+  matrix_timer = timer_read32();
+  matrix_scan_count = 0;
+#endif
+}
+
+// Returns a matrix_row_t whose bits are set if the corresponding key should be
+// eligible to change in this scan.
+matrix_row_t debounce_mask(uint8_t row) {
+  matrix_row_t result = 0;
+  for (uint8_t j=0; j < MATRIX_COLS; ++j) {
+    if (debounce_matrix[row * MATRIX_COLS + j]) {
+      --debounce_matrix[row * MATRIX_COLS + j];
+    } else {
+      result |= (1 << j);
+    }
+  }
+  return result;
+}
+
+// Report changed keys in the given row.  Resets the debounce countdowns
+// corresponding to each set bit in 'change' to DEBOUNCE.
+void debounce_report(matrix_row_t change, uint8_t row) {
+  for (uint8_t i = 0; i < MATRIX_COLS; ++i) {
+    if (change & (1 << i)) {
+      debounce_matrix[row * MATRIX_COLS + i] = DEBOUNCE;
+    }
+  }
+}
+
+uint8_t matrix_scan(void)
+{
+  expander_scan();
+
+#ifdef DEBUG_MATRIX_SCAN_RATE
+  matrix_scan_count++;
+
+  uint32_t timer_now = timer_read32();
+  if (TIMER_DIFF_32(timer_now, matrix_timer)>1000) {
+    print("matrix scan frequency: ");
+    pdec(matrix_scan_count);
+    print("\n");
+    matrix_print();
+
+    matrix_timer = timer_now;
+    matrix_scan_count = 0;
+  }
+#endif
+
+  for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+    select_row(i);
+    wait_us(30);  // without this wait read unstable value.
+    matrix_row_t mask = debounce_mask(i);
+    matrix_row_t cols = (read_cols(i) & mask) | (matrix[i] & ~mask);
+    debounce_report(cols ^ matrix[i], i);
+    matrix[i] = cols;
+
+    unselect_rows();
+  }
+
+  matrix_scan_quantum();
+
+  return 1;
+}
+
+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;
+}
+
+/* Column pin configuration
+ *
+ * Pro Micro: 6    5    4    3    2    1    0
+ *            PD3  PD2  PD4  PC6  PD7  PE6  PB4
+ *
+ * Expander:  13   12   11   10   9    8    7
+ */
+static void  init_cols(void)
+{
+  // Pro Micro
+  DDRE  &= ~(1<<PE6);
+  PORTE |=  (1<<PE6);
+  DDRD  &= ~(1<<PD2 | 1<<PD3 | 1<<PD4 | 1<<PD7);
+  PORTD |=  (1<<PD2 | 1<<PD3 | 1<<PD4 | 1<<PD7);
+  DDRC  &= ~(1<<PC6);
+  PORTC |=  (1<<PC6);
+  DDRB  &= ~(1<<PB4);
+  PORTB |=  (1<<PB4);
+
+  // MCP23017
+  expander_init();
+}
+
+static matrix_row_t read_cols(uint8_t row)
+{
+  return expander_read_row() |
+    (PIND&(1<<PD3) ? 0 : (1<<6)) |
+    (PIND&(1<<PD2) ? 0 : (1<<5)) |
+    (PIND&(1<<PD4) ? 0 : (1<<4)) |
+    (PINC&(1<<PC6) ? 0 : (1<<3)) |
+    (PIND&(1<<PD7) ? 0 : (1<<2)) |
+    (PINE&(1<<PE6) ? 0 : (1<<1)) |
+    (PINB&(1<<PB4) ? 0 : (1<<0)) ;
+}
+
+/* Row pin configuration
+ *
+ * Pro Micro: 0   1   2   3   4   5
+ *            F4  F5  F6  F7  B1  B2
+ *
+ * Expander:  0   1   2   3   4   5
+ */
+static void unselect_rows(void)
+{
+  // Pro Micro
+  DDRF  &= ~(1<<PF4 | 1<<PF5 | 1<<PF6 | 1<<PF7);
+  PORTF &= ~(1<<PF4 | 1<<PF5 | 1<<PF6 | 1<<PF7);
+  DDRB  &= ~(1<<PB1 | 1<<PB2);
+  PORTB &= ~(1<<PB1 | 1<<PB2);
+
+  // Expander
+  expander_unselect_rows();
+}
+
+static void select_row(uint8_t row)
+{
+  // Pro Micro
+  switch (row) {
+  case 0:
+    DDRF  |=  (1<<PF4);
+    PORTF &= ~(1<<PF4);
+    break;
+  case 1:
+    DDRF  |=  (1<<PF5);
+    PORTF &= ~(1<<PF5);
+    break;
+  case 2:
+    DDRF  |=  (1<<PF6);
+    PORTF &= ~(1<<PF6);
+    break;
+  case 3:
+    DDRF  |=  (1<<PF7);
+    PORTF &= ~(1<<PF7);
+    break;
+  case 4:
+    DDRB  |=  (1<<PB1);
+    PORTB &= ~(1<<PB1);
+    break;
+  case 5:
+    DDRB  |=  (1<<PB2);
+    PORTB &= ~(1<<PB2);
+    break;
+  }
+
+  expander_select_row(row);
+}
+
diff --git a/keyboards/ergodone/readme.md b/keyboards/ergodone/readme.md
new file mode 100644
index 000000000..789819e67
--- /dev/null
+++ b/keyboards/ergodone/readme.md
@@ -0,0 +1,26 @@
+ErgoDone
+===
+
+![ErgoDone](https://i.imgur.com/QERsQGQ.jpg)
+
+ErgoDone is a modified ErgoDox with pre-soldered components made by K.T.E.C. It has different wiring and uses a Pro Micro instead of Teensy.
+
+  - Keyboard Maintainer: [Yu He](http://github.com/yuhe00)
+  - Hardware Supported: 
+    - ErgoDone ver. 1.3 (tested)
+  - Hardware Availability: [KBDFans](https://kbdfans.myshopify.com/collections/pcb/products/ergodone-keyboard-pcb-1pcs-free-shipping?variant=37178300237)
+
+Make example for this keyboard (after setting up your build environment):
+
+    make ergodox-ergodone-default
+
+See [build environment setup](https://docs.qmk.fm/build_environment_setup.html) then the [make instructions](https://docs.qmk.fm/make_instructions.html) for more information.
+
+# Flashing the keyboard
+
+The ErgoDone uses an HID bootloader rather than the Teensy one, and requires a different way of flashing the firmware.
+
+1. While plugging in the USB cable, hold the two right-most keys on the left half of the ErgoDone to enter FLASH mode.
+2. Use the `hid_bootloader_cli` utlity from [TKG Toolkit](https://github.com/kairyu/tkg-toolkit):
+   
+        hid_bootloader_cli -mmcu=atmega32u4 ergodox_ergodone_default
diff --git a/keyboards/ergodone/rules.mk b/keyboards/ergodone/rules.mk
new file mode 100644
index 000000000..bbad0ae73
--- /dev/null
+++ b/keyboards/ergodone/rules.mk
@@ -0,0 +1,95 @@
+#----------------------------------------------------------------------------
+# On command line:
+#
+# make = Make software.
+#
+# make clean = Clean out built project files.
+#
+# That's pretty much all you need. To compile, always go make clean, 
+# followed by make.
+#
+# For advanced users only:
+# make teensy = Download the hex file to the device, using teensy_loader_cli.
+#               (must have teensy_loader_cli installed).
+#
+#----------------------------------------------------------------------------
+
+# # project specific files
+SRC = \
+    twimaster.c \
+          matrix.c    \
+    expander.c  \
+
+# MCU name
+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
+#   comment out to disable the options.
+#
+CUSTOM_MATRIX           = yes # Custom matrix file for the ErgoDone
+UNICODE_ENABLE          = yes # Unicode
+BOOTMAGIC_ENABLE        = yes   # 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          = no  # Commands for debug and configuration
+SLEEP_LED_ENABLE        = no  # Breathing sleep LED during USB suspend
+NKRO_ENABLE             = yes   # USB Nkey Rollover - not yet supported in LUFA
+USB_6KRO_ENABLE         = no  # USB 6key Rollover
+BACKLIGHT_ENABLE        = no    # Enable keyboard backlight functionality
+KEYMAP_IN_EEPROM_ENABLE = no    # External keymap in eeprom
+KEYMAP_SECTION_ENABLE   = no    # Fixed address keymap for keymap editor
+SOFTPWM_LED_ENABLE      = no  # Enable SoftPWM to drive backlight
+FADING_LED_ENABLE       = no  # Enable fading backlight
+BREATHING_LED_ENABLE    = no  # Enable breathing backlight
+LEDMAP_ENABLE           = no    # Enable LED mapping
+LEDMAP_IN_EEPROM_ENABLE = no  # Read LED mapping from eeprom
+ONEHAND_ENABLE          = no  # Disable Onehand
+RGBLIGHT_ENABLE         = no
+MIDI_ENABLE             = no
+
+LAYOUTS = ergodox ergodox_80
\ No newline at end of file
diff --git a/keyboards/ergodone/twimaster.c b/keyboards/ergodone/twimaster.c
new file mode 100644
index 000000000..f91c08e6e
--- /dev/null
+++ b/keyboards/ergodone/twimaster.c
@@ -0,0 +1,208 @@
+/*************************************************************************
+* Title:    I2C master library using hardware TWI interface
+* Author:   Peter Fleury <pfleury@gmx.ch>  http://jump.to/fleury
+* File:     $Id: twimaster.c,v 1.3 2005/07/02 11:14:21 Peter Exp $
+* Software: AVR-GCC 3.4.3 / avr-libc 1.2.3
+* Target:   any AVR device with hardware TWI 
+* Usage:    API compatible with I2C Software Library i2cmaster.h
+**************************************************************************/
+#include <inttypes.h>
+#include <compat/twi.h>
+
+#include <i2cmaster.h>
+
+
+/* define CPU frequency in Mhz here if not defined in Makefile */
+#ifndef F_CPU
+#define F_CPU 16000000UL
+#endif
+
+/* I2C clock in Hz */
+#define SCL_CLOCK  400000L
+
+
+/*************************************************************************
+ Initialization of the I2C bus interface. Need to be called only once
+*************************************************************************/
+void i2c_init(void)
+{
+  /* initialize TWI clock
+   * minimal values in Bit Rate Register (TWBR) and minimal Prescaler
+   * bits in the TWI Status Register should give us maximal possible
+   * I2C bus speed - about 444 kHz
+   *
+   * for more details, see 20.5.2 in ATmega16/32 secification
+   */
+  
+  TWSR = 0;     /* no prescaler */
+  TWBR = 10;    /* must be >= 10 for stable operation */
+
+}/* i2c_init */
+
+
+/*************************************************************************      
+  Issues a start condition and sends address and transfer direction.
+  return 0 = device accessible, 1= failed to access device
+*************************************************************************/
+unsigned char i2c_start(unsigned char address)
+{
+    uint8_t   twst;
+
+        // send START condition
+        TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+
+        // wait until transmission completed
+        while(!(TWCR & (1<<TWINT)));
+
+        // check value of TWI Status Register. Mask prescaler bits.
+        twst = TW_STATUS & 0xF8;
+        if ( (twst != TW_START) && (twst != TW_REP_START)) return 1;
+
+        // send device address
+        TWDR = address;
+        TWCR = (1<<TWINT) | (1<<TWEN);
+
+        // wail until transmission completed and ACK/NACK has been received
+        while(!(TWCR & (1<<TWINT)));
+
+        // check value of TWI Status Register. Mask prescaler bits.
+        twst = TW_STATUS & 0xF8;
+        if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return 1;
+
+        return 0;
+
+}/* i2c_start */
+
+
+/*************************************************************************
+ Issues a start condition and sends address and transfer direction.
+ If device is busy, use ack polling to wait until device is ready
+ 
+ Input:   address and transfer direction of I2C device
+*************************************************************************/
+void i2c_start_wait(unsigned char address)
+{
+    uint8_t   twst;
+
+
+    while ( 1 )
+    {
+            // send START condition
+            TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+    
+        // wait until transmission completed
+        while(!(TWCR & (1<<TWINT)));
+    
+        // check value of TWI Status Register. Mask prescaler bits.
+        twst = TW_STATUS & 0xF8;
+        if ( (twst != TW_START) && (twst != TW_REP_START)) continue;
+    
+        // send device address
+        TWDR = address;
+        TWCR = (1<<TWINT) | (1<<TWEN);
+    
+        // wail until transmission completed
+        while(!(TWCR & (1<<TWINT)));
+    
+        // check value of TWI Status Register. Mask prescaler bits.
+        twst = TW_STATUS & 0xF8;
+        if ( (twst == TW_MT_SLA_NACK )||(twst ==TW_MR_DATA_NACK) ) 
+        {           
+            /* device busy, send stop condition to terminate write operation */
+                TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
+                
+                // wait until stop condition is executed and bus released
+                while(TWCR & (1<<TWSTO));
+                
+            continue;
+        }
+        //if( twst != TW_MT_SLA_ACK) return 1;
+        break;
+     }
+
+}/* i2c_start_wait */
+
+
+/*************************************************************************
+ Issues a repeated start condition and sends address and transfer direction 
+
+ Input:   address and transfer direction of I2C device
+ 
+ Return:  0 device accessible
+          1 failed to access device
+*************************************************************************/
+unsigned char i2c_rep_start(unsigned char address)
+{
+    return i2c_start( address );
+
+}/* i2c_rep_start */
+
+
+/*************************************************************************
+ Terminates the data transfer and releases the I2C bus
+*************************************************************************/
+void i2c_stop(void)
+{
+    /* send stop condition */
+        TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
+        
+        // wait until stop condition is executed and bus released
+        while(TWCR & (1<<TWSTO));
+
+}/* i2c_stop */
+
+
+/*************************************************************************
+  Send one byte to I2C device
+  
+  Input:    byte to be transfered
+  Return:   0 write successful 
+            1 write failed
+*************************************************************************/
+unsigned char i2c_write( unsigned char data )
+{       
+    uint8_t   twst;
+    
+        // send data to the previously addressed device
+        TWDR = data;
+        TWCR = (1<<TWINT) | (1<<TWEN);
+
+        // wait until transmission completed
+        while(!(TWCR & (1<<TWINT)));
+
+        // check value of TWI Status Register. Mask prescaler bits
+        twst = TW_STATUS & 0xF8;
+        if( twst != TW_MT_DATA_ACK) return 1;
+        return 0;
+
+}/* i2c_write */
+
+
+/*************************************************************************
+ Read one byte from the I2C device, request more data from device 
+ 
+ Return:  byte read from I2C device
+*************************************************************************/
+unsigned char i2c_readAck(void)
+{
+        TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
+        while(!(TWCR & (1<<TWINT)));    
+
+    return TWDR;
+
+}/* i2c_readAck */
+
+
+/*************************************************************************
+ Read one byte from the I2C device, read is followed by a stop condition 
+ 
+ Return:  byte read from I2C device
+*************************************************************************/
+unsigned char i2c_readNak(void)
+{
+        TWCR = (1<<TWINT) | (1<<TWEN);
+        while(!(TWCR & (1<<TWINT)));
+        
+    return TWDR;
+
+}/* i2c_readNak */