File content as of revision 3:f18aa98bc9a8:

/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
 * Copyright (c) 2007-2010, sford, http://mbed.org
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "LCD_nonblocking.h"
#include "mbed.h"





TextLCD::TextLCD(PinName rs, PinName e, PinName d4, PinName d5,
                 PinName d6, PinName d7, LCDType type) : busy(0),_rs(rs),
    _e(e), _d(d4, d5, d6, d7),
    _type(type) , _column(0),_row(0),
    _head(0), _tail(0) {}
void TextLCD::init()
{

    busy=1;
    _rs = 1;
    _d  = 0;
    wait_us(1);
    _e  = 0;
    _rs = 0;            // command mode
    timer.attach_us(this,&TextLCD::init2,15000);
}
void TextLCD::init2()
{
    _rs = 0;
    _d = 0x3;
    _e = 1;
    wait_us(1);
    _e = 0;
    timer.attach_us(this,&TextLCD::init2b,4100);
}
void TextLCD::init2b()
{

    _d = 0x3;
    _e = 1;
    wait_us(1);
    _e = 0;
    timer.attach_us(this,&TextLCD::init3,4100);
}
void TextLCD::init3()
{
    _d = 0x3;
    _e = 1;
    wait_us(1);
    _e = 0;
    timer.attach_us(this,&TextLCD::init4,1000);
}
void TextLCD::init4()
{
    _d = 0x2;
    _e = 1;
    wait_us(1);
    _e = 0;
    timer.attach_us(this,&TextLCD::init5,60);
}
void TextLCD::init5()
{

    writeByte(0x28); // Function set 001 BW N F - -
    timer.attach_us(this,&TextLCD::init6,60);
}
void TextLCD::init6()
{
    writeByte(0x0C);
    timer.attach_us(this,&TextLCD::init7,60);
}
void TextLCD::init7()
{
    writeByte(0x6);  // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes
    timer.attach_us(this,&TextLCD::init8,60);
}
void TextLCD::init8()
{
    writeByte(0x01); // cls, and set cursor to 0
    // This command takes 1.64 ms
    locate(0, 0);
    timer.attach_us(this,&TextLCD::locate_cb,1640);
}
/*
void TextLCD::character(int column, int row, int c)
{
    int a = address(column, row);
    writeCommand(a);
    writeData(c);
}
*/
void TextLCD::cls()
{
    busy=1;
    writeByte(0x01); // cls, and set cursor to 0
    // This command takes 1.64 ms
    locate(0, 0);
    timer.attach_us(this,&TextLCD::locate_cb,1640);
}

void TextLCD::locate(int column, int row)
{
    _column = column;
    _row = row;
}
/* this is the general buffered-write callback for writing text to the display
 * it normally chains to itself unless a newline occurs in which case it chains to
 * locate_cb
 * or the buffer runs out in which case it clears busy and does not chain
 */

void TextLCD::callback()
{
    if (_tail<_head) {
        int value=_queue[_tail++];
        if (value == '\n') {
            _column = 0;
            _row++;
            if (_row >= rows()) {
                _row = 0;
            }
            locate_cb(); // newline isn't printed so go straight to "locate" code
        } else {
            _rs = 1; // data mode
            writeByte(value);
            _column++;
            if (_column >= columns()) { //if we've reached the end of line then chain to "locate"
                                        //otherwise go back to callback
                _column = 0;
                _row++;
                if (_row >= rows()) {
                    _row = 0;
                }
                timer.attach_us(this,&TextLCD::locate_cb,60);
            } else {
                timer.attach_us(this,&TextLCD::callback,60);
            }

        }

    } else {  //if we've run out of text then clear flag
        _head=_tail=0;
        busy=0;
    }
}

void TextLCD::locate_cb()
{
    int a = address(_column, _row);
    _rs=0;
    writeByte(a);
    timer.attach_us(this,&TextLCD::callback,60);
}


int TextLCD::_putc(int value)
{
    if (_head<40) {
        _queue[_head++]=value;
    };
    if (busy==0) {
        busy=1;
        locate_cb(); // set cursor position before text
        /*
        int a = address(_column, _row);
        _rs=0;
        writeByte(a);
        timer.attach_us(this,&TextLCD::callback,60);
        */
    };
    return 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;
    _e = 1;
    wait_us(1);
    _e = 0;
    _d = value >> 0;
    wait_us(2);
    _e = 1;
    wait_us(1);  // most instructions take 40us
    _e = 0;
}

void TextLCD::writeCommand(int command)
{
    _rs = 0;  //command mode
    wait_us(50); // most instructions take 40us
    writeByte(command);
}

void TextLCD::writeData(int data)
{
    _rs = 1; // data mode
    wait_us(50); // most instructions take 40us
    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;
    }
}