File content as of revision 0:3087f1924901:

/* mbed LCD Library, for a 4-bit LCD based on HD44780
 * Copyright (c) 2007-2012, hb9gaa
 */

#include "LCD.h"
#include "mbed.h"

TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, PinName d2, PinName d3, LCDType type) : _rs(rs), _rw(rw), _e(e), _d(d0, d1, d2, d3), _type(type) 
    {
    _e  = 1;
    _rw = 0;
    _rs = 0;                // command mode

     wait(0.015);           // Wait 15ms to ensure powered up

    // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
    for (int i=0; i<3; i++) 
        {
        writeByte(0x3);
        wait_ms(1.64);      // this command takes 1.64ms, so wait for it
        }
    writeByte(0x2);         // 4-bit mode
    wait_ms(0.1);           // most instructions take 100us

    writeCommand(0x28);     // Function set 001 BW N F - -
    writeCommand(0x0C);
    writeCommand(0x6);      // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
    cls();
    }


void TextLCD::character(int column, int row, int c) 
    {
    int a = address(column, row);
    writeCommand(a);
    writeData(c);
    }


void TextLCD::cls() 
    {
    writeCommand(0x01);     // cls, and set cursor to 0
    wait_ms(4.1);           // This command takes 4.1 ms
    locate(0, 0);
    }


void TextLCD::locate(int column, int row) 
    {
    _column = column;
    _row = row;
    }


int TextLCD::_putc(int value) 
    {
    if (value == '\n') 
        {
        _column = 0;
        _row++;
        if (_row >= rows()) 
            {
            _row = 0;
            }
        } 
    else 
        {
        character(_column, _row, value);
        _column++;
        if (_column >= columns()) 
            {
            _column = 0;
            _row++;
            if (_row >= rows()) 
                {
                _row = 0;
                }
            }
        }
    return value;
    }


int TextLCD::_getc() 
    {
    return -1;
    }


void TextLCD::writeByte(int value) 
    {
    _d = value >> 4;
    wait(0.0001);       // most instructions take 100us
    _e = 0;
    wait(0.0001);
    _e = 1;
    _d = value >> 0;
    wait(0.0001);
    _e = 0;
    wait(0.0001);
    _e = 1;
    }


void TextLCD::writeCommand(int command) 
    {
    _rs = 0;
    writeByte(command);
    }


void TextLCD::writeData(int data) 
    {
    _rs = 1;
    writeByte(data);
    }


int TextLCD::address(int column, int row) 
    {
    switch (_type) 
        {
        case LCD20x4:
            switch (row) 
                {
                case 0:
                    return 0x80 + column;
                case 1:
                    return 0xc0 + column;
                case 2:
                    return 0x94 + column;
                case 3:
                    return 0xd4 + column;
                }
        case LCD16x2B:
            return 0x80 + (row * 40) + column;
        case LCD16x2:
        case LCD20x2:
        default:
            return 0x80 + (row * 0x40) + column;
        }
    }


int TextLCD::columns() 
    {
    switch (_type) 
        {
        case LCD20x4:
        case LCD20x2:
            return 20;
        case LCD16x2:
        case LCD16x2B:
        default:
            return 16;
        }
    }


int TextLCD::rows() 
    {
    switch (_type) 
        {
        case LCD20x4:
            return 4;
        case LCD16x2:
        case LCD16x2B:
        case LCD20x2:
        default:
            return 2;
        }
    }


void TextLCD::buildChar(unsigned char *p)
    {
     unsigned char i, j;
     
     for(j=0;j<8;j++)                    //CGRAM Adresse
         {
         writeCommand(0x40+(j*8));       //Write to CGRAM
         for(i=0;i<8;i++)
            writeData(p[i+(j*8)]);       //Write the character pattern to CGRAM
         }
        writeCommand(0x80);              //shift back to DDRAM location 0
    }