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// ---------------------------------------------------------------------------
// Created by Francisco Malpartida on 20/08/11.
// Copyright 2011 - Under creative commons license 3.0:
// Attribution-ShareAlike CC BY-SA
//
// This software is furnished "as is", without technical support, and with no
// warranty, express or implied, as to its usefulness for any purpose.
//
// Thread Safe: No
// Extendable: Yes
//
// @file LiquidCrystal_I2C.c
// This file implements a basic liquid crystal library that comes as standard
// in the Arduino SDK but using an I2C IO extension board.
//
// @brief
// This is a basic implementation of the LiquidCrystal library of the
// Arduino SDK. The original library has been reworked in such a way that
// this class implements the all methods to command an LCD based
// on the Hitachi HD44780 and compatible chipsets using I2C extension
// backpacks such as the I2CLCDextraIO with the PCF8574* I2C IO Expander ASIC.
//
// The functionality provided by this class and its base class is identical
// to the original functionality of the Arduino LiquidCrystal library.
//
//
// This library is only compatible with Arduino's SDK version 1.0
//
//
// @author F. Malpartida - fmalpartida@gmail.com
// ---------------------------------------------------------------------------
#if (ARDUINO < 100)
#include <WProgram.h>
#else
#include <Arduino.h>
#endif
#include <inttypes.h>
#include <I2CIO.h>
#include <LiquidCrystal_I2C.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_I2C constructor is called).
// A call to begin() will reinitialize the LCD.
// CONSTRUCTORS
// ---------------------------------------------------------------------------
LiquidCrystal_I2C::LiquidCrystal_I2C( uint8_t lcd_Addr )
{
_Addr = lcd_Addr;
_backlightval = LCD_NOBACKLIGHT;
_En = EN;
_Rw = RW;
_Rs = RS;
// Initialise default values data[0] pin 0, data[1] pin 1, ...
for ( uint8_t i = 0; i < 4; i++ )
{
_data_pins[i] = ( 1 << i );
}
}
LiquidCrystal_I2C::LiquidCrystal_I2C( uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
uint8_t Rs)
{
_Addr = lcd_Addr;
_backlightval = LCD_NOBACKLIGHT;
_En = ( 1 << En );
_Rw = ( 1 << Rw );
_Rs = ( 1 << Rs );
// Initialise default values data[0] pin 0, data[1] pin 1, ...
for ( uint8_t i = 0; i < 4; i++ )
{
_data_pins[i] = ( 1 << i );
}
}
LiquidCrystal_I2C::LiquidCrystal_I2C( uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
uint8_t Rs, uint8_t d0, uint8_t d1,
uint8_t d2, uint8_t d3 )
{
_Addr = lcd_Addr;
_backlightval = LCD_NOBACKLIGHT;
_En = ( 1 << En );
_Rw = ( 1 << Rw );
_Rs = ( 1 << Rs );
// Initialise pin mapping
_data_pins[0] = ( 1 << d0 );
_data_pins[1] = ( 1 << d1 );
_data_pins[2] = ( 1 << d2 );
_data_pins[3] = ( 1 << d3 );
}
// PRIVATE METHODS
// ---------------------------------------------------------------------------
//
// init
int LiquidCrystal_I2C::init()
{
int status = 0;
// initialize the backpack IO expander
// and display functions.
// ------------------------------------------------------------------------
if ( _i2cio.begin ( _Addr ) == 1 )
{
_i2cio.portMode ( OUTPUT ); // Set the entire IO extender to OUTPUT
_displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
status = 1;
}
return ( status );
}
// PUBLIC METHODS
// ---------------------------------------------------------------------------
//
// begin
void LiquidCrystal_I2C::begin(uint8_t cols, uint8_t lines, uint8_t dotsize)
{
init(); // Initialise the I2C expander interface
if (lines > 1)
{
_displayfunction |= LCD_2LINE;
}
_numlines = lines;
_cols = cols;
// for some 1 line displays you can select a 10 pixel high font
if ((dotsize != 0) && (lines == 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 before 4.5V so we'll wait 50
delayMicroseconds(50000);
// Now we pull both RS and R/W low to begin commands
expanderWrite ( _backlightval ); // reset expander and 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, LOW );
delayMicroseconds(4500); // wait min 4.1ms
// second try
write4bits ( 0x03, LOW );
delayMicroseconds(4500); // wait min 4.1ms
// third go!
write4bits ( 0x03, LOW );
delayMicroseconds(150);
// finally, set to 4-bit interface
write4bits ( 0x02, LOW );
// 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();
}
// User commands - users can expand this section
//----------------------------------------------------------------------------
// 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);
}
// PRIVATE METHODS
// ---------------------------------------------------------------------------
// low level data pushing commands
//----------------------------------------------------------------------------
//
// send - write either command or data
void LiquidCrystal_I2C::send(uint8_t value, uint8_t mode)
{
// No need to use the delay routines since the time taken to write takes
// longer that what is needed both for toggling and enable pin an to execute
// the command.
write4bits( (value >> 4), mode );
write4bits( (value & 0x0F), mode);
}
//
// write4bits
void LiquidCrystal_I2C::write4bits ( uint8_t value, uint8_t mode )
{
uint8_t pinMapValue = 0;
// Map the value to LCD pin mapping
// --------------------------------
for ( uint8_t i = 0; i < 4; i++ )
{
if ( ( value & 0x1 ) == 1 )
{
pinMapValue |= _data_pins[i];
}
value = ( value >> 1 );
}
// Is it a command or data
// -----------------------
if ( mode == DATA )
{
mode = _Rs;
}
expanderWrite ( pinMapValue | mode );
pulseEnable ( pinMapValue | mode );
}
//
// write4bits
void LiquidCrystal_I2C::pulseEnable (uint8_t _data)
{
expanderWrite (_data | _En); // En HIGH
expanderWrite(_data & ~_En); // En LOW
}
//
// expanderWrite
void LiquidCrystal_I2C::expanderWrite(uint8_t _data)
{
_i2cio.write ( _data );
}