Permalink
Switch branches/tags
Nothing to show
Find file
Fetching contributors…
Cannot retrieve contributors at this time
202 lines (176 sloc) 5.25 KB
// ---------------------------------------------------------------------------
// 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 HD44780.h
// This file implements a basic liquid crystal library that comes as standard
// in the Arduino SDK.
//
// @brief
// This is a basic implementation of the HD44780 library of the
// Arduino SDK. This library is a refactored version of the one supplied
// in the Arduino SDK in such a way that it simplifies its extension
// to support other mechanism to communicate to LCDs such as I2C, Serial.
// The original library has been reworked in such a way that this will be
// the base class implementing all generic methods to command an LCD based
// on the Hitachi HD44780 and compatible chipsets.
//
// This base class is a pure abstract class and needs to be extended. As reference,
// it has been extended to drive 4 and 8 bit mode control, LCDs and I2C extension
// backpacks such as the I2CLCDextraIO using the PCF8574* I2C IO Expander ASIC.
//
//
// This library is only compatible with Arduino's SDK version 1.0
//
// @version API 1.0.0
//
// @author F. Malpartida - fmalpartida@gmail.com
// ---------------------------------------------------------------------------
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#if (ARDUINO < 100)
#include <WProgram.h>
#else
#include <Arduino.h>
#endif
#include <LCD.h>
// CLASS CONSTRUCTORS
// ---------------------------------------------------------------------------
// Constructor
LCD::LCD ()
{
}
// PUBLIC METHODS
// ---------------------------------------------------------------------------
// Common LCD Commands
// ---------------------------------------------------------------------------
void LCD::clear()
{
command(LCD_CLEARDISPLAY); // clear display, set cursor position to zero
delayMicroseconds(HOME_CLEAR_EXEC); // this command is time consuming
}
void LCD::home()
{
command(LCD_RETURNHOME); // set cursor position to zero
delayMicroseconds(HOME_CLEAR_EXEC); // This command is time consuming
}
void LCD::setCursor(uint8_t col, uint8_t row)
{
int row_offsetsDef[] = { 0x00, 0x40, 0x14, 0x54 }; // For regular LCDs
int row_offsetsLarge[] = { 0x00, 0x40, 0x10, 0x50 }; // For 16x4 LCDs
if ( row >= _numlines )
{
row = _numlines-1; // rows start at 0
}
// 16x4 LCDs have special memory map layout
// ----------------------------------------
if ( _cols == 16 && _numlines == 4 )
{
command(LCD_SETDDRAMADDR | (col + row_offsetsLarge[row]));
}
else
{
command(LCD_SETDDRAMADDR | (col + row_offsetsDef[row]));
}
}
// Turn the display on/off
void LCD::noDisplay()
{
_displaycontrol &= ~LCD_DISPLAYON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LCD::display()
{
_displaycontrol |= LCD_DISPLAYON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
// Turns the underline cursor on/off
void LCD::noCursor()
{
_displaycontrol &= ~LCD_CURSORON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LCD::cursor()
{
_displaycontrol |= LCD_CURSORON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
// Turns on/off the blinking cursor
void LCD::noBlink()
{
_displaycontrol &= ~LCD_BLINKON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LCD::blink()
{
_displaycontrol |= LCD_BLINKON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
// These commands scroll the display without changing the RAM
void LCD::scrollDisplayLeft(void)
{
command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
}
void LCD::scrollDisplayRight(void) {
command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}
// This is for text that flows Left to Right
void LCD::leftToRight(void)
{
_displaymode |= LCD_ENTRYLEFT;
command(LCD_ENTRYMODESET | _displaymode);
}
// This is for text that flows Right to Left
void LCD::rightToLeft(void)
{
_displaymode &= ~LCD_ENTRYLEFT;
command(LCD_ENTRYMODESET | _displaymode);
}
// This will 'right justify' text from the cursor
void LCD::autoscroll(void)
{
_displaymode |= LCD_ENTRYSHIFTINCREMENT;
command(LCD_ENTRYMODESET | _displaymode);
}
// This will 'left justify' text from the cursor
void LCD::noAutoscroll(void)
{
_displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
command(LCD_ENTRYMODESET | _displaymode);
}
// Write to CGRAM of new characters
void LCD::createChar(uint8_t location, uint8_t charmap[])
{
location &= 0x7; // we only have 8 locations 0-7
command(LCD_SETCGRAMADDR | (location << 3));
for (int i=0; i<8; i++)
{
write(charmap[i]); // call the virtual write method
}
}
// General LCD commands - generic methods used by the rest of the commands
// ---------------------------------------------------------------------------
void LCD::command(uint8_t value)
{
send(value, COMMAND);
}
#if (ARDUINO < 100)
void LCD::write(uint8_t value)
{
send(value, DATA);
}
#else
size_t LCD::write(uint8_t value)
{
send(value, DATA);
return 1; // assume OK
}
#endif