LCD Library 1.2.1
LCD Library - LCD control class hierarchy library. Drop in replacement for the LiquidCrystal Library.
/Users/fmalpartida/development/ardWorkspace/LiquidCrystal_I2C/LiquiCrystal_I2C/FastIO.cpp
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00001 // ---------------------------------------------------------------------------
00002 // Created by Francisco Malpartida on 20/08/11.
00003 // Copyright 2011 - Under creative commons license 3.0:
00004 //        Attribution-ShareAlike CC BY-SA
00005 //
00006 // This software is furnished "as is", without technical support, and with no 
00007 // warranty, express or implied, as to its usefulness for any purpose.
00008 //
00009 // Thread Safe: No
00010 // Extendable: Yes
00011 //
00012 // @file LiquidCrystal_I2C.c
00013 // This file implements a basic liquid crystal library that comes as standard
00014 // in the Arduino SDK but using an I2C IO extension board.
00015 // 
00016 // @brief 
00017 // This is a basic implementation of the LiquidCrystal library of the
00018 // Arduino SDK. The original library has been reworked in such a way that 
00019 // this class implements the all methods to command an LCD based
00020 // on the Hitachi HD44780 and compatible chipsets using I2C extension
00021 // backpacks such as the I2CLCDextraIO with the PCF8574* I2C IO Expander ASIC.
00022 //
00023 // The functionality provided by this class and its base class is identical
00024 // to the original functionality of the Arduino LiquidCrystal library.
00025 //
00026 //
00027 //
00028 // @author F. Malpartida - [email protected]
00029 // ---------------------------------------------------------------------------
00030 #if (ARDUINO <  100)
00031  #include <WProgram.h>
00032 #else
00033  #include <Arduino.h>
00034 #endif
00035  #include <inttypes.h>
00036 #include "I2CIO.h"
00037 #include "LiquidCrystal_I2C.h"
00038 
00039 // CONSTANT  definitions
00040 // ---------------------------------------------------------------------------
00041 
00042 // flags for backlight control
00048  #define LCD_NOBACKLIGHT 0x00
00049  
00055 #define LCD_BACKLIGHT   0xFF
00056  
00057 
00058 // Default library configuration parameters used by class constructor with
00059 // only the I2C address field.
00060 // ---------------------------------------------------------------------------
00066  #define EN 6  // Enable bit
00067  
00073 #define RW 5  // Read/Write bit
00074  
00080 #define RS 4  // Register select bit
00081  
00088 #define D4 0
00089  #define D5 1
00090  #define D6 2
00091  #define D7 3
00092  
00093 
00094 // CONSTRUCTORS
00095 // ---------------------------------------------------------------------------
00096 LiquidCrystal_I2C::LiquidCrystal_I2C( uint8_t lcd_Addr )
00097 {
00098    config(lcd_Addr, EN, RW, RS, D4, D5, D6, D7);
00099 }
00100 
00101 
00102 LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t backlighPin, 
00103                                      t_backlighPol pol = POSITIVE)
00104 {
00105    config(lcd_Addr, EN, RW, RS, D4, D5, D6, D7);
00106    setBacklightPin(backlighPin, pol);
00107 }
00108 
00109 LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
00110                                      uint8_t Rs)
00111 {
00112    config(lcd_Addr, En, Rw, Rs, D4, D5, D6, D7);
00113 }
00114 
00115 LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
00116                                      uint8_t Rs, uint8_t backlighPin, 
00117                                      t_backlighPol pol = POSITIVE)
00118 {
00119    config(lcd_Addr, En, Rw, Rs, D4, D5, D6, D7);
00120    setBacklightPin(backlighPin, pol);
00121 }
00122 
00123 LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
00124                                      uint8_t Rs, uint8_t d4, uint8_t d5,
00125                                      uint8_t d6, uint8_t d7 )
00126 {
00127    config(lcd_Addr, En, Rw, Rs, d4, d5, d6, d7);
00128 }
00129 
00130 LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
00131                                      uint8_t Rs, uint8_t d4, uint8_t d5,
00132                                      uint8_t d6, uint8_t d7, uint8_t backlighPin, 
00133                                      t_backlighPol pol = POSITIVE )
00134 {
00135    config(lcd_Addr, En, Rw, Rs, d4, d5, d6, d7);
00136    setBacklightPin(backlighPin, pol);
00137 }
00138 
00139 // PUBLIC METHODS
00140 // ---------------------------------------------------------------------------
00141 
00142 //
00143 // begin
00144 void LiquidCrystal_I2C::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) 
00145 {
00146    
00147    init();     // Initialise the I2C expander interface
00148    LCD::begin ( cols, lines, dotsize );   
00149 }
00150 
00151 
00152 // User commands - users can expand this section
00153 //----------------------------------------------------------------------------
00154 // Turn the (optional) backlight off/on
00155 
00156 //
00157 // setBacklightPin
00158 void LiquidCrystal_I2C::setBacklightPin ( uint8_t value, t_backlighPol pol = POSITIVE )
00159 {
00160    _backlightPinMask = ( 1 << value );
00161    _polarity = pol;
00162    setBacklight(BACKLIGHT_OFF);
00163 }
00164 
00165 //
00166 // setBacklight
00167 void LiquidCrystal_I2C::setBacklight( uint8_t value ) 
00168 {
00169    // Check if backlight is available
00170    // ----------------------------------------------------
00171    if ( _backlightPinMask != 0x0 )
00172    {
00173       // Check for polarity to configure mask accordingly
00174       // ----------------------------------------------------------
00175       if  (((_polarity == POSITIVE) && (value > 0)) || 
00176            ((_polarity == NEGATIVE ) && ( value == 0 )))
00177       {
00178          _backlightStsMask = _backlightPinMask & LCD_BACKLIGHT;
00179       }
00180       else 
00181       {
00182          _backlightStsMask = _backlightPinMask & LCD_NOBACKLIGHT;
00183       }
00184       _i2cio.write( _backlightStsMask );
00185    }
00186 }
00187 
00188 
00189 // PRIVATE METHODS
00190 // ---------------------------------------------------------------------------
00191 
00192 //
00193 // init
00194 int LiquidCrystal_I2C::init()
00195 {
00196    int status = 0;
00197    
00198    // initialize the backpack IO expander
00199    // and display functions.
00200    // ------------------------------------------------------------------------
00201    if ( _i2cio.begin ( _Addr ) == 1 )
00202    {
00203       _i2cio.portMode ( OUTPUT );  // Set the entire IO extender to OUTPUT
00204       _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
00205       status = 1;
00206       _i2cio.write(0);  // Set the entire port to LOW
00207    }
00208    return ( status );
00209 }
00210 
00211 //
00212 // config
00213 void LiquidCrystal_I2C::config (uint8_t lcd_Addr, uint8_t En, uint8_t Rw, uint8_t Rs, 
00214                                 uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7 )
00215 {
00216    _Addr = lcd_Addr;
00217    
00218    _backlightPinMask = 0;
00219    _backlightStsMask = LCD_NOBACKLIGHT;
00220    _polarity = POSITIVE;
00221    
00222    _En = ( 1 << En );
00223    _Rw = ( 1 << Rw );
00224    _Rs = ( 1 << Rs );
00225    
00226    // Initialise pin mapping
00227    _data_pins[0] = ( 1 << d4 );
00228    _data_pins[1] = ( 1 << d5 );
00229    _data_pins[2] = ( 1 << d6 );
00230    _data_pins[3] = ( 1 << d7 );   
00231 }
00232 
00233 
00234 
00235 // low level data pushing commands
00236 //----------------------------------------------------------------------------
00237 
00238 //
00239 // send - write either command or data
00240 void LiquidCrystal_I2C::send(uint8_t value, uint8_t mode) 
00241 {
00242    // No need to use the delay routines since the time taken to write takes
00243    // longer that what is needed both for toggling and enable pin an to execute
00244    // the command.
00245    
00246    if ( mode == FOUR_BITS )
00247    {
00248       write4bits( (value & 0x0F), COMMAND );
00249    }
00250    else 
00251    {
00252       write4bits( (value >> 4), mode );
00253       write4bits( (value & 0x0F), mode);
00254    }
00255 }
00256 
00257 //
00258 // write4bits
00259 void LiquidCrystal_I2C::write4bits ( uint8_t value, uint8_t mode ) 
00260 {
00261    uint8_t pinMapValue = 0;
00262    
00263    // Map the value to LCD pin mapping
00264    // --------------------------------
00265    for ( uint8_t i = 0; i < 4; i++ )
00266    {
00267       if ( ( value & 0x1 ) == 1 )
00268       {
00269          pinMapValue |= _data_pins[i];
00270       }
00271       value = ( value >> 1 );
00272    }
00273    
00274    // Is it a command or data
00275    // -----------------------
00276    if ( mode == DATA )
00277    {
00278       mode = _Rs;
00279    }
00280    
00281    pinMapValue |= mode | _backlightStsMask;
00282    pulseEnable ( pinMapValue );
00283 }
00284 
00285 //
00286 // pulseEnable
00287 void LiquidCrystal_I2C::pulseEnable (uint8_t data)
00288 {
00289    _i2cio.write (data | _En);   // En HIGH
00290    _i2cio.write (data & ~_En);  // En LOW
00291 }
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