File content as of revision 0:824096cc05af:

#include "LiquidCrystal_I2C.h"
#include "mbed.h"

// When the display powers up, it is configured as follows:
//
// 1. Display clear
// 2. Function set:
//    DL = 1; 8-bit interface data
//    N = 0; 1-line display
//    F = 0; 5x8 dot character font
// 3. Display on/off control:
//    D = 0; Display off
//    C = 0; Cursor off
//    B = 0; Blinking off
// 4. Entry mode set:
//    I/D = 1; Increment by 1
//    S = 0; No shift
//
// Note, however, that resetting the Arduino doesn't reset the LCD, so we
// can't assume that its in that state when a sketch starts (and the
// LiquidCrystal constructor is called).


I2C _i2c(PB_11, PB_10); // SDA, SCL

LiquidCrystal_I2C::LiquidCrystal_I2C(unsigned char lcd_addr, unsigned char lcd_cols, unsigned char lcd_rows, unsigned char charsize)
{
    _addr = lcd_addr;
    _cols = lcd_cols;
    _rows = lcd_rows;
    _charsize = charsize;
    _backlightval = LCD_BACKLIGHT;
}

void LiquidCrystal_I2C::begin() {
    //Wire.begin();
    _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;

    if (_rows > 1) {
        _displayfunction |= LCD_2LINE;
    }

    // for some 1 line displays you can select a 10 pixel high font
    if ((_charsize != 0) && (_rows == 1)) {
        _displayfunction |= LCD_5x10DOTS;
    }

    // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
    // according to datasheet, we need at least 40ms after power rises above 2.7V
    // before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50
    wait_ms(50);

    // Now we pull both RS and R/W low to begin commands
    expanderWrite(_backlightval);   // reset expanderand turn backlight off (Bit 8 =1)
    wait_ms(1000);

    //put the LCD into 4 bit mode
    // this is according to the hitachi HD44780 datasheet
    // figure 24, pg 46

    // we start in 8bit mode, try to set 4 bit mode
    write4bits(0x03 << 4);
    wait_us(4500); // wait min 4.1ms

    // second try
    write4bits(0x03 << 4);
    wait_us(4500); // wait min 4.1ms

    // third go!
    write4bits(0x03 << 4);
    wait_us(150);

    // finally, set to 4-bit interface
    write4bits(0x02 << 4);

    // set # lines, font size, etc.
    command(LCD_FUNCTIONSET | _displayfunction);

    // turn the display on with no cursor or blinking default
    _displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
    display();

    // clear it off
    clear();

    // Initialize to default text direction (for roman languages)
    _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;

    // set the entry mode
    command(LCD_ENTRYMODESET | _displaymode);

    home();
}

/********** high level commands, for the user! */
void LiquidCrystal_I2C::clear(){
    command(LCD_CLEARDISPLAY);// clear display, set cursor position to zero
    wait_us(2000);  // this command takes a long time!
}

void LiquidCrystal_I2C::home(){
    command(LCD_RETURNHOME);  // set cursor position to zero
    wait_us(2000);  // this command takes a long time!
}

void LiquidCrystal_I2C::setCursor(unsigned char col, unsigned char row){
    int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
    if (row > _rows) {
        row = _rows-1;    // we count rows starting w/0
    }
    command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
}

// Turn the display on/off (quickly)
void LiquidCrystal_I2C::noDisplay() {
    _displaycontrol &= ~LCD_DISPLAYON;
    command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_I2C::display() {
    _displaycontrol |= LCD_DISPLAYON;
    command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// Turns the underline cursor on/off
void LiquidCrystal_I2C::noCursor() {
    _displaycontrol &= ~LCD_CURSORON;
    command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_I2C::cursor() {
    _displaycontrol |= LCD_CURSORON;
    command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// Turn on and off the blinking cursor
void LiquidCrystal_I2C::noBlink() {
    _displaycontrol &= ~LCD_BLINKON;
    command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_I2C::blink() {
    _displaycontrol |= LCD_BLINKON;
    command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// These commands scroll the display without changing the RAM
void LiquidCrystal_I2C::scrollDisplayLeft(void) {
    command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
}
void LiquidCrystal_I2C::scrollDisplayRight(void) {
    command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}

// This is for text that flows Left to Right
void LiquidCrystal_I2C::leftToRight(void) {
    _displaymode |= LCD_ENTRYLEFT;
    command(LCD_ENTRYMODESET | _displaymode);
}

// This is for text that flows Right to Left
void LiquidCrystal_I2C::rightToLeft(void) {
    _displaymode &= ~LCD_ENTRYLEFT;
    command(LCD_ENTRYMODESET | _displaymode);
}

// This will 'right justify' text from the cursor
void LiquidCrystal_I2C::autoscroll(void) {
    _displaymode |= LCD_ENTRYSHIFTINCREMENT;
    command(LCD_ENTRYMODESET | _displaymode);
}

// This will 'left justify' text from the cursor
void LiquidCrystal_I2C::noAutoscroll(void) {
    _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
    command(LCD_ENTRYMODESET | _displaymode);
}

// Allows us to fill the first 8 CGRAM locations
// with custom characters
void LiquidCrystal_I2C::createChar(unsigned char location, unsigned char charmap[]) {
    location &= 0x7; // we only have 8 locations 0-7
    command(LCD_SETCGRAMADDR | (location << 3));
    for (int i=0; i<8; i++) {
        write(charmap[i]);
    }
}

// Turn the (optional) backlight off/on
void LiquidCrystal_I2C::noBacklight(void) {
    _backlightval=LCD_NOBACKLIGHT;
    expanderWrite(0);
}

void LiquidCrystal_I2C::backlight(void) {
    _backlightval=LCD_BACKLIGHT;
    expanderWrite(0);
}
bool LiquidCrystal_I2C::getBacklight() {
  return _backlightval == LCD_BACKLIGHT;
}


/*********** mid level commands, for sending data/cmds */

inline void LiquidCrystal_I2C::command(unsigned char value) {
    send(value, 0);
}

inline int LiquidCrystal_I2C::write(unsigned char value) {
    send(value, Rs);
    return 1;
}


/************ low level data pushing commands **********/

// write either command or data
void LiquidCrystal_I2C::send(unsigned char value, unsigned char mode) {
    unsigned char highnib=value&0xf0;
    unsigned char lownib=(value<<4)&0xf0;
    write4bits((highnib)|mode);
    write4bits((lownib)|mode);
}

void LiquidCrystal_I2C::write4bits(unsigned char value) {
    expanderWrite(value);
    pulseEnable(value);
}

void LiquidCrystal_I2C::expanderWrite(unsigned char _data){
    char data_write[2];
    data_write[0] = _data | _backlightval;
    //Wire.beginTransmission(_addr);
    //Wire.write((int)(_data) | _backlightval);
    //Wire.endTransmission();
    _i2c.write(_addr, data_write, 1, 0);
    _i2c.stop();
}

void LiquidCrystal_I2C::pulseEnable(unsigned char _data){
    expanderWrite(_data | En);  // En high
    wait_us(1);       // enable pulse must be >450ns

    expanderWrite(_data & ~En); // En low
    wait_us(50);      // commands need > 37us to settle
}

void LiquidCrystal_I2C::load_custom_character(unsigned char char_num, unsigned char *rows){
    createChar(char_num, rows);
}

void LiquidCrystal_I2C::setBacklight(unsigned char new_val){
    if (new_val) {
        backlight();        // turn backlight on
    } else {
        noBacklight();      // turn backlight off
    }
}

void LiquidCrystal_I2C::printstr(const char c[]){
    //This function is not identical to the function used for "real" I2C displays
    //it's here so the user sketch doesn't have to be changed
    //print(c);
}

int LiquidCrystal_I2C::print(const char* text) {
  
  while (*text !=0) {
    //_putc(*text);
    send(*text, Rs);
    text++;
  }
  return 0;
}

/*
void lcd_dat(unsigned char p)
{
PORTC |= (1 << RS)|(1 << EN); // RS = 1, EN = 1 (начало записи команды в LCD)
PORTD = p; // Вывод команды на шину DB0-7 LCD
_delay_us(100); // Длительность сигнала EN
PORTC &= ~(1 << EN); // EN = 0 (конец записи команды в LCD)
_delay_us(100); // Пауза для выполнения команды
}
*/