LiquidCrystal_I2C.cpp

#include "LiquidCrystal_I2C.h"
#include <inttypes.h>
#include <Arduino.h>
#include <Wire.h>


LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_addr, uint8_t lcd_cols, uint8_t lcd_rows, uint8_t charsize)
{
_addr = lcd_addr;
_cols = lcd_cols;
_rows = lcd_rows;
_charsize = charsize;
_backlightval = LCD_BACKLIGHT;

// Add for 4004 LCD
if (lcd_cols == 40 && lcd_rows == 4)
_useTwoChips = true;
else
_useTwoChips = false;
_useEnable2 = false;
}

void LiquidCrystal_I2C::begin() {
Wire.begin();
Wire.setClock(400000);
_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
delay(50);

// Now we pull both RS and R/W low to begin commands
expanderWrite(_backlightval); // reset expanderand turn backlight off (Bit 8 =1)
delay(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);
delayMicroseconds(4500); // wait min 4.1ms

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

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

if (_useTwoChips) {
_useEnable2 = true;
// 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
delay(50);

// Now we pull both RS and R/W low to begin commands
expanderWrite(_backlightval); // reset expanderand turn backlight off (Bit 8 =1)
delay(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);
delayMicroseconds(4500); // wait min 4.1ms

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

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

_useEnable2 = false;
}
}

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

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

void LiquidCrystal_I2C::setCursor(uint8_t col, uint8_t row){
int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
int row_offsets4004[] = { 0x00, 0x40, 0x00, 0x40 };
if (row > _rows) {
row = _rows-1;    // we count rows starting w/0
}
if (_useTwoChips) {
if ( row > 1)
_useEnable2 = true;
else
_useEnable2 = false;
command(LCD_SETDDRAMADDR | (col + row_offsets4004[row]));
} else {
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(uint8_t location, uint8_t charmap[]) {

	location &= 0x7; // we only have 8 locations 0-7
	if (_useTwoChips) {
		_useEnable2 = false;
		command(LCD_SETCGRAMADDR | (location << 3));
		for (int i=0; i<8; i++) {
		write(charmap[i]);
		}

		_useEnable2 = true;
		command(LCD_SETCGRAMADDR | (location << 3));
		for (int i=0; i<8; i++) {
		write(charmap[i]);
		}
	} else {
		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(uint8_t value) {
send(value, 0);
}

inline size_t LiquidCrystal_I2C::write(uint8_t value) {
send(value, Rs);
return 1;
}


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

// write either command or data
void LiquidCrystal_I2C::send(uint8_t value, uint8_t mode) {
uint8_t highnib=value&0xf0;
uint8_t lownib=(value<<4)&0xf0;
write4bits((highnib)|mode);
write4bits((lownib)|mode);
}

void LiquidCrystal_I2C::write4bits(uint8_t value) {
expanderWrite(value);
pulseEnable(value);
}

void LiquidCrystal_I2C::expanderWrite(uint8_t _data){
Wire.beginTransmission(_addr);
Wire.write((int)(_data) | _backlightval);
Wire.endTransmission();
}

void LiquidCrystal_I2C::pulseEnable(uint8_t _data){
if (_useEnable2) {
expanderWrite(_data | En2); // En high
delayMicroseconds(1); // enable pulse must be >450ns

expanderWrite(_data & ~En2); // En low
delayMicroseconds(50); // commands need > 37us to settle
} else {
expanderWrite(_data | En); // En high
delayMicroseconds(1); // enable pulse must be >450ns

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

void LiquidCrystal_I2C::load_custom_character(uint8_t char_num, uint8_t *rows){
createChar(char_num, rows);
}

void LiquidCrystal_I2C::setBacklight(uint8_t 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);
}