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/Users/fmalpartida/development/ardWorkspace/LiquidCrystal_I2C/LiquiCrystal_I2C/LCD.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 LCD.cpp
    00013 // This file implements a basic liquid crystal library that comes as standard
    00014 // in the Arduino SDK.
    00015 //
    00016 // @brief
    00017 // This is a basic implementation of the HD44780 library of the
    00018 // Arduino SDK. This library is a refactored version of the one supplied
    00019 // in the Arduino SDK in such a way that it simplifies its extension
    00020 // to support other mechanism to communicate to LCDs such as I2C, Serial, SR, ...
    00021 // The original library has been reworked in such a way that this will be
    00022 // the base class implementing all generic methods to command an LCD based
    00023 // on the Hitachi HD44780 and compatible chipsets.
    00024 //
    00025 // This base class is a pure abstract class and needs to be extended. As reference,
    00026 // it has been extended to drive 4 and 8 bit mode control, LCDs and I2C extension
    00027 // backpacks such as the I2CLCDextraIO using the PCF8574* I2C IO Expander ASIC.
    00028 //
    00029 //
    00030 // @version API 1.1.0
    00031 //
    00032 // 2012.03.29 bperrybap - changed comparision to use LCD_5x8DOTS rather than 0
    00033 // @author F. Malpartida - fmalpartida@gmail.com
    00034 // ---------------------------------------------------------------------------
    00035 #include <stdio.h>
    00036 #include <string.h>
    00037 #include <inttypes.h>
    00038
    00039 #if (ARDUINO <  100)
    00040 #include <WProgram.h>
    00041 #else
    00042 #include <Arduino.h>
    00043 #endif
    00044 #include "LCD.h"
    00045
    00046 // CLASS CONSTRUCTORS
    00047 // ---------------------------------------------------------------------------
    00048 // Constructor
    00049 LCD::LCD ()
    00050 {
    00051
    00052 }
    00053
    00054 // PUBLIC METHODS
    00055 // ---------------------------------------------------------------------------
    00056 // When the display powers up, it is configured as follows:
    00057 //
    00058 // 1. Display clear
    00059 // 2. Function set:
    00060 //    DL = 1; 8-bit interface data
    00061 //    N = 0; 1-line display
    00062 //    F = 0; 5x8 dot character font
    00063 // 3. Display on/off control:
    00064 //    D = 0; Display off
    00065 //    C = 0; Cursor off
    00066 //    B = 0; Blinking off
    00067 // 4. Entry mode set:
    00068 //    I/D = 1; Increment by 1
    00069 //    S = 0; No shift
    00070 //
    00071 // Note, however, that resetting the Arduino doesn't reset the LCD, so we
    00072 // can't assume that its in that state when a sketch starts (and the
    00073 // LiquidCrystal constructor is called).
    00074 // A call to begin() will reinitialize the LCD.
    00075 //
    00076 void LCD::begin(uint8_t cols, uint8_t lines, uint8_t dotsize)
    00077 {
    00078    if (lines > 1)
    00079    {
    00080       _displayfunction |= LCD_2LINE;
    00081    }
    00082    _numlines = lines;
    00083    _cols = cols;
    00084
    00085    // for some 1 line displays you can select a 10 pixel high font
    00086    // ------------------------------------------------------------
    00087    if ((dotsize != LCD_5x8DOTS) && (lines == 1))
    00088    {
    00089       _displayfunction |= LCD_5x10DOTS;
    00090    }
    00091
    00092    // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
    00093    // according to datasheet, we need at least 40ms after power rises above 2.7V
    00094    // before sending commands. Arduino can turn on way before 4.5V so we'll wait
    00095    // 50
    00096    // ---------------------------------------------------------------------------
    00097    delay (100); // 100ms delay
    00098
    00099    //put the LCD into 4 bit or 8 bit mode
    00100    // -------------------------------------
    00101    if (! (_displayfunction & LCD_8BITMODE))
    00102    {
    00103       // this is according to the hitachi HD44780 datasheet
    00104       // figure 24, pg 46
    00105
    00106       // we start in 8bit mode, try to set 4 bit mode
    00107       send(0x03, FOUR_BITS);
    00108       delayMicroseconds(4500); // wait min 4.1ms
    00109
    00110       // second try
    00111       send ( 0x03, FOUR_BITS );
    00112       delayMicroseconds(4500); // wait min 4.1ms
    00113
    00114       // third go!
    00115       send( 0x03, FOUR_BITS );
    00116       delayMicroseconds(150);
    00117
    00118       // finally, set to 4-bit interface
    00119       send ( 0x02, FOUR_BITS );
    00120    }
    00121    else
    00122    {
    00123       // this is according to the hitachi HD44780 datasheet
    00124       // page 45 figure 23
    00125
    00126       // Send function set command sequence
    00127       command(LCD_FUNCTIONSET | _displayfunction);
    00128       delayMicroseconds(4500);  // wait more than 4.1ms
    00129
    00130       // second try
    00131       command(LCD_FUNCTIONSET | _displayfunction);
    00132       delayMicroseconds(150);
    00133
    00134       // third go
    00135       command(LCD_FUNCTIONSET | _displayfunction);
    00136    }
    00137
    00138    // finally, set # lines, font size, etc.
    00139    command(LCD_FUNCTIONSET | _displayfunction);
    00140
    00141    // turn the display on with no cursor or blinking default
    00142    _displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
    00143    display();
    00144
    00145    // clear the LCD
    00146    clear();
    00147
    00148    // Initialize to default text direction (for romance languages)
    00149    _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
    00150    // set the entry mode
    00151    command(LCD_ENTRYMODESET | _displaymode);
    00152
    00153    backlight();
    00154
    00155 }
    00156
    00157 // Common LCD Commands
    00158 // ---------------------------------------------------------------------------
    00159 void LCD::clear()
    00160 {
    00161    command(LCD_CLEARDISPLAY);             // clear display, set cursor position to zero
    00162    delayMicroseconds(HOME_CLEAR_EXEC);    // this command is time consuming
    00163 }
    00164
    00165 void LCD::home()
    00166 {
    00167    command(LCD_RETURNHOME);             // set cursor position to zero
    00168    delayMicroseconds(HOME_CLEAR_EXEC);  // This command is time consuming
    00169 }
    00170
    00171 void LCD::setCursor(uint8_t col, uint8_t row)
    00172 {
    00173    const byte row_offsetsDef[]   = { 0x00, 0x40, 0x14, 0x54 }; // For regular LCDs
    00174    const byte row_offsetsLarge[] = { 0x00, 0x40, 0x10, 0x50 }; // For 16x4 LCDs
    00175
    00176    if ( row >= _numlines )
    00177    {
    00178       row = _numlines-1;    // rows start at 0
    00179    }
    00180
    00181    // 16x4 LCDs have special memory map layout
    00182    // ----------------------------------------
    00183    if ( _cols == 16 && _numlines == 4 )
    00184    {
    00185       command(LCD_SETDDRAMADDR | (col + row_offsetsLarge[row]));
    00186    }
    00187    else
    00188    {
    00189       command(LCD_SETDDRAMADDR | (col + row_offsetsDef[row]));
    00190    }
    00191
    00192 }
    00193
    00194 // Turn the display on/off
    00195 void LCD::noDisplay()
    00196 {
    00197    _displaycontrol &= ~LCD_DISPLAYON;
    00198    command(LCD_DISPLAYCONTROL | _displaycontrol);
    00199 }
    00200
    00201 void LCD::display()
    00202 {
    00203    _displaycontrol |= LCD_DISPLAYON;
    00204    command(LCD_DISPLAYCONTROL | _displaycontrol);
    00205 }
    00206
    00207 // Turns the underline cursor on/off
    00208 void LCD::noCursor()
    00209 {
    00210    _displaycontrol &= ~LCD_CURSORON;
    00211    command(LCD_DISPLAYCONTROL | _displaycontrol);
    00212 }
    00213 void LCD::cursor()
    00214 {
    00215    _displaycontrol |= LCD_CURSORON;
    00216    command(LCD_DISPLAYCONTROL | _displaycontrol);
    00217 }
    00218
    00219 // Turns on/off the blinking cursor
    00220 void LCD::noBlink()
    00221 {
    00222    _displaycontrol &= ~LCD_BLINKON;
    00223    command(LCD_DISPLAYCONTROL | _displaycontrol);
    00224 }
    00225
    00226 void LCD::blink()
    00227 {
    00228    _displaycontrol |= LCD_BLINKON;
    00229    command(LCD_DISPLAYCONTROL | _displaycontrol);
    00230 }
    00231
    00232 // These commands scroll the display without changing the RAM
    00233 void LCD::scrollDisplayLeft(void)
    00234 {
    00235    command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
    00236 }
    00237
    00238 void LCD::scrollDisplayRight(void)
    00239 {
    00240    command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
    00241 }
    00242
    00243 // This is for text that flows Left to Right
    00244 void LCD::leftToRight(void)
    00245 {
    00246    _displaymode |= LCD_ENTRYLEFT;
    00247    command(LCD_ENTRYMODESET | _displaymode);
    00248 }
    00249
    00250 // This is for text that flows Right to Left
    00251 void LCD::rightToLeft(void)
    00252 {
    00253    _displaymode &= ~LCD_ENTRYLEFT;
    00254    command(LCD_ENTRYMODESET | _displaymode);
    00255 }
    00256
    00257 // This method moves the cursor one space to the right
    00258 void LCD::moveCursorRight(void)
    00259 {
    00260    command(LCD_CURSORSHIFT | LCD_CURSORMOVE | LCD_MOVERIGHT);
    00261 }
    00262
    00263 // This method moves the cursor one space to the left
    00264 void LCD::moveCursorLeft(void)
    00265 {
    00266    command(LCD_CURSORSHIFT | LCD_CURSORMOVE | LCD_MOVELEFT);
    00267 }
    00268
    00269
    00270 // This will 'right justify' text from the cursor
    00271 void LCD::autoscroll(void)
    00272 {
    00273    _displaymode |= LCD_ENTRYSHIFTINCREMENT;
    00274    command(LCD_ENTRYMODESET | _displaymode);
    00275 }
    00276
    00277 // This will 'left justify' text from the cursor
    00278 void LCD::noAutoscroll(void)
    00279 {
    00280    _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
    00281    command(LCD_ENTRYMODESET | _displaymode);
    00282 }
    00283
    00284 // Write to CGRAM of new characters
    00285 void LCD::createChar(uint8_t location, uint8_t charmap[])
    00286 {
    00287    location &= 0x7;            // we only have 8 locations 0-7
    00288
    00289    command(LCD_SETCGRAMADDR | (location << 3));
    00290    delayMicroseconds(30);
    00291
    00292    for (int i=0; i<8; i++)
    00293    {
    00294       write(charmap[i]);      // call the virtual write method
    00295       delayMicroseconds(40);
    00296    }
    00297 }
    00298
    00299 //
    00300 // Switch on the backlight
    00301 void LCD::backlight ( void )
    00302 {
    00303    setBacklight(255);
    00304 }
    00305
    00306 //
    00307 // Switch off the backlight
    00308 void LCD::noBacklight ( void )
    00309 {
    00310    setBacklight(0);
    00311 }
    00312
    00313 //
    00314 // Switch fully on the LCD (backlight and LCD)
    00315 void LCD::on ( void )
    00316 {
    00317    display();
    00318    backlight();
    00319 }
    00320
    00321 //
    00322 // Switch fully off the LCD (backlight and LCD)
    00323 void LCD::off ( void )
    00324 {
    00325    noBacklight();
    00326    noDisplay();
    00327 }
    00328
    00329 // General LCD commands - generic methods used by the rest of the commands
    00330 // ---------------------------------------------------------------------------
    00331 void LCD::command(uint8_t value)
    00332 {
    00333    send(value, COMMAND);
    00334 }
    00335
    00336 #if (ARDUINO <  100)
    00337 void LCD::write(uint8_t value)
    00338 {
    00339    send(value, DATA);
    00340 }
    00341 #else
    00342 size_t LCD::write(uint8_t value)
    00343 {
    00344    send(value, DATA);
    00345    return 1;             // assume OK
    00346 }
    00347 #endif

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