// ---------------------------------------------------------------------------
// 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 LCD.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 LiquidCrystal 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, SR,
// 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.
//
// The functionality provided by this class and its base class is identical
// to the original functionality of the Arduino LiquidCrystal library.
//
// @version API 1.1.0
//
//
// @author F. Malpartida - fmalpartida@gmail.com
// ---------------------------------------------------------------------------
#ifndef _LCD_H_
#define _LCD_H_
#if (ARDUINO < 100)
#include <WProgram.h>
#else
#include <Arduino.h>
#endif
#include <inttypes.h>
#include <Print.h>
/*!
@defined
@abstract Enables disables fast waits for write operations for LCD
@discussion If defined, the library will avoid doing un-necessary waits.
this can be done, because the time taken by Arduino's slow digitalWrite
operations. If fast digitalIO operations, comment this line out or undefine
the mode.
*/
#ifdef __AVR__
#define FAST_MODE
#endif
/*!
@function
@abstract waits for a given time in microseconds (compilation dependent).
@discussion Waits for a given time defined in microseconds depending on
the FAST_MODE define. If the FAST_MODE is defined the call will return
inmediatelly.
@param uSec[in] time in microseconds.
@result None
*/
inline static void waitUsec ( uint16_t uSec )
{
#ifndef FAST_MODE
delayMicroseconds ( uSec );
#endif // FAST_MODE
}
/*!
@defined
@abstract All these definitions shouldn't be used unless you are writing
a driver.
@discussion All these definitions are for driver implementation only and
shouldn't be used by applications.
*/
// LCD Commands
// ---------------------------------------------------------------------------
#define LCD_CLEARDISPLAY 0x01
#define LCD_RETURNHOME 0x02
#define LCD_ENTRYMODESET 0x04
#define LCD_DISPLAYCONTROL 0x08
#define LCD_CURSORSHIFT 0x10
#define LCD_FUNCTIONSET 0x20
#define LCD_SETCGRAMADDR 0x40
#define LCD_SETDDRAMADDR 0x80
// flags for display entry mode
// ---------------------------------------------------------------------------
#define LCD_ENTRYRIGHT 0x00
#define LCD_ENTRYLEFT 0x02
#define LCD_ENTRYSHIFTINCREMENT 0x01
#define LCD_ENTRYSHIFTDECREMENT 0x00
// flags for display on/off and cursor control
// ---------------------------------------------------------------------------
#define LCD_DISPLAYON 0x04
#define LCD_DISPLAYOFF 0x00
#define LCD_CURSORON 0x02
#define LCD_CURSOROFF 0x00
#define LCD_BLINKON 0x01
#define LCD_BLINKOFF 0x00
// flags for display/cursor shift
// ---------------------------------------------------------------------------
#define LCD_DISPLAYMOVE 0x08
#define LCD_CURSORMOVE 0x00
#define LCD_MOVERIGHT 0x04
#define LCD_MOVELEFT 0x00
// flags for function set
// ---------------------------------------------------------------------------
#define LCD_8BITMODE 0x10
#define LCD_4BITMODE 0x00
#define LCD_2LINE 0x08
#define LCD_1LINE 0x00
#define LCD_5x10DOTS 0x04
#define LCD_5x8DOTS 0x00
// Define COMMAND and DATA LCD Rs (used by send method).
// ---------------------------------------------------------------------------
#define COMMAND 0
#define DATA 1
#define FOUR_BITS 2
/*!
@defined
@abstract Defines the duration of the home and clear commands
@discussion This constant defines the time it takes for the home and clear
commands in the LCD - Time in microseconds.
*/
#define HOME_CLEAR_EXEC 2000
/*!
@defined
@abstract Backlight off constant declaration
@discussion Used in combination with the setBacklight to swith off the
LCD backlight. @set setBacklight
*/
#define BACKLIGHT_OFF 0
/*!
@defined
@abstract Backlight on constant declaration
@discussion Used in combination with the setBacklight to swith on the
LCD backlight. @set setBacklight
*/
#define BACKLIGHT_ON 255
/*!
@typedef
@abstract Define backlight control polarity
@discussion Backlight control polarity. @see setBacklightPin.
*/
typedef enum { POSITIVE, NEGATIVE } t_backlighPol;
class LCD : public Print
{
public:
/*!
@method
@abstract LiquidCrystal abstract constructor.
@discussion LiquidCrystal class abstract constructor needed to create
the base abstract class.
*/
LCD ( );
/*!
@function
@abstract LCD initialization.
@discussion Initializes the LCD to a given size (col, row). This methods
initializes the LCD, therefore, it MUST be called prior to using any other
method from this class.
This method is abstract, a base implementation is available common to all LCD
drivers. Should it not be compatible with some other LCD driver, a derived
implementation should be done on the driver specif class.
@param cols[in] the number of columns that the display has
@param rows[in] the number of rows that the display has
@param charsize[in] character size, default==LCD_5x8DOTS
*/
virtual void begin(uint8_t cols, uint8_t rows, uint8_t charsize = LCD_5x8DOTS);
/*!
@function
@abstract Clears the LCD.
@discussion Clears the LCD screen and positions the cursor in the upper-left
corner.
This operation is time consuming for the LCD.
@param none
*/
void clear();
/*!
@function
@abstract Sets the cursor to the upper-left corner.
@discussion Positions the cursor in the upper-left of the LCD.
That is, use that location in outputting subsequent text to the display.
To also clear the display, use the clear() function instead.
This operation is time consuming for the LCD.
@param none
*/
void home();
/*!
@function
@abstract Turns off the LCD display.
@discussion Turns off the LCD display, without losing the text currently
being displayed on it.
@param none
*/
void noDisplay();
/*!
@function
@abstract Turns on the LCD display.
@discussion Turns on the LCD display, after it's been turned off with
noDisplay(). This will restore the text (and cursor location) that was on
the display prior to calling noDisplay().
@param none
*/
void display();
/*!
@function
@abstract Turns off the blinking of the LCD cursor.
@param none
*/
void noBlink();
/*!
@function
@abstract Display the cursor of the LCD.
@discussion Display the blinking LCD cursor. If used in combination with
the cursor() function, the result will depend on the particular display.
@param none
*/
void blink();
/*!
@function
@abstract Hides the LCD cursor.
@param none
*/
void noCursor();
/*!
@function
@abstract Display the LCD cursor.
@discussion Display the LCD cursor: an underscore (line) at the location
where the next character will be written.
@param none
*/
void cursor();
/*!
@function
@abstract Scrolls the contents of the display (text and cursor) one space
to the left.
@param none
*/
void scrollDisplayLeft();
/*!
@function
@abstract Scrolls the contents of the display (text and cursor) one space
to the right.
@param none
*/
void scrollDisplayRight();
/*!
@function
@abstract Set the direction for text written to the LCD to left-to-right.
@discussion Set the direction for text written to the LCD to left-to-right.
All subsequent characters written to the display will go from left to right,
but does not affect previously-output text.
This is the default configuration.
@param none
*/
void leftToRight();
/*!
@function
@abstract Set the direction for text written to the LCD to right-to-left.
@discussion Set the direction for text written to the LCD to right-to-left.
All subsequent characters written to the display will go from right to left,
but does not affect previously-output text.
left-to-right is the default configuration.
@param none
*/
void rightToLeft();
/*!
@function
@abstract Moves the cursor one space to the left.
@discussion
@param none
*/
void moveCursorLeft();
/*!
@function
@abstract Moves the cursor one space to the right.
@param none
*/
void moveCursorRight();
/*!
@function
@abstract Turns on automatic scrolling of the LCD.
@discussion Turns on automatic scrolling of the LCD. This causes each
character output to the display to push previous characters over by one
space. If the current text direction is left-to-right (the default),
the display scrolls to the left; if the current direction is right-to-left,
the display scrolls to the right.
This has the effect of outputting each new character to the same location on
the LCD.
@param none
*/
void autoscroll();
/*!
@function
@abstract Turns off automatic scrolling of the LCD.
@discussion Turns off automatic scrolling of the LCD, this is the default
configuration of the LCD.
@param none
*/
void noAutoscroll();
/*!
@function
@abstract Creates a custom character for use on the LCD.
@discussion Create a custom character (glyph) for use on the LCD.
Most chipsets only support up to eight characters of 5x8 pixels. Therefore,
this methods has been limited to locations (numbered 0 to 7).
The appearance of each custom character is specified by an array of eight
bytes, one for each row. The five least significant bits of each byte
determine the pixels in that row. To display a custom character on screen,
write()/print() its number, i.e. lcd.print (char(x)); // Where x is 0..7.
@param location[in] LCD memory location of the character to create
(0 to 7)
@param charmap[in] the bitmap array representing each row of the character.
*/
void createChar(uint8_t location, uint8_t charmap[]);
/*!
@function
@abstract Position the LCD cursor.
@discussion Sets the position of the LCD cursor. Set the location at which
subsequent text written to the LCD will be displayed.
@param col[in] LCD column
@param row[in] LCD row - line.
*/
void setCursor(uint8_t col, uint8_t row);
/*!
@function
@abstract Switch-on the LCD backlight.
@discussion Switch-on the LCD backlight.
The setBacklightPin has to be called before setting the backlight for
this method to work. @see setBacklightPin.
*/
void backlight ( void );
/*!
@function
@abstract Switch-off the LCD backlight.
@discussion Switch-off the LCD backlight.
The setBacklightPin has to be called before setting the backlight for
this method to work. @see setBacklightPin.
*/
void noBacklight ( void );
/*!
@function
@abstract Switch on the LCD module.
@discussion Switch on the LCD module, it will switch on the LCD controller
and the backlight. This method has the same effect of calling display and
backlight. @see display, @see backlight
*/
void on ( void );
/*!
@function
@abstract Switch off the LCD module.
@discussion Switch off the LCD module, it will switch off the LCD controller
and the backlight. This method has the same effect of calling noDisplay and
noBacklight. @see display, @see backlight
*/
void off ( void );
//
// virtual class methods
// --------------------------------------------------------------------------
/*!
@function
@abstract Sets the pin to control the backlight.
@discussion Sets the pin in the device to control the backlight.
This method is device dependent and can be programmed on each subclass. An
empty function call is provided that does nothing.
@param value: pin associated to backlight control.
@param pol: backlight polarity control (POSITIVE, NEGATIVE)
*/
virtual void setBacklightPin ( uint8_t value, t_backlighPol pol ) { };
/*!
@function
@abstract Sets the pin to control the backlight.
@discussion Sets the pin in the device to control the backlight. The behaviour
of this method is very dependent on the device. Some controllers support
dimming some don't. Please read the actual header file for each individual
device. The setBacklightPin method has to be called before setting the backlight
or the adequate backlight control constructor.
@see setBacklightPin.
NOTE: The prefered methods to control the backlight are "backlight" and
"noBacklight".
@param 0..255 - the value is very dependent on the LCD. However,
BACKLIGHT_OFF will be interpreted as off and BACKLIGHT_ON will drive the
backlight on.
*/
virtual void setBacklight ( uint8_t value ) { };
/*!
@function
@abstract Writes to the LCD.
@discussion This method writes character to the LCD in the current cursor
position.
This is the virtual write method, implemented in the Print class, therefore
all Print class methods will end up calling this method.
@param value[in] Value to write to the LCD.
*/
#if (ARDUINO < 100)
virtual void write(uint8_t value);
#else
virtual size_t write(uint8_t value);
#endif
#if (ARDUINO < 100)
using Print::write;
#else
using Print::write;
#endif
protected:
// Internal LCD variables to control the LCD shared between all derived
// classes.
uint8_t _displayfunction; // LCD_5x10DOTS or LCD_5x8DOTS, LCD_4BITMODE or
// LCD_8BITMODE, LCD_1LINE or LCD_2LINE
uint8_t _displaycontrol; // LCD base control command LCD on/off, blink, cursor
// all commands are "ored" to its contents.
uint8_t _displaymode; // Text entry mode to the LCD
uint8_t _numlines; // Number of lines of the LCD, initialized with begin()
uint8_t _cols; // Number of columns in the LCD
t_backlighPol _polarity; // Backlight polarity
private:
/*!
@function
@abstract Send a command to the LCD.
@discussion This method sends a command to the LCD by setting the Register
select line of the LCD.
This command shouldn't be used to drive the LCD, only to implement any other
feature that is not available on this library.
@param value[in] Command value to send to the LCD (COMMAND, DATA or
FOUR_BITS).
*/
void command(uint8_t value);
/*!
@function
@abstract Send a particular value to the LCD.
@discussion Sends a particular value to the LCD. This is a pure abstract
method, therefore, it is implementation dependent of each derived class how
to physically write to the LCD.
Users should never call this method.
@param value[in] Value to send to the LCD.
@result mode LOW - write to the LCD CGRAM, HIGH - write a command to
the LCD.
*/
#if (ARDUINO < 100)
virtual void send(uint8_t value, uint8_t mode) { };
#else
virtual void send(uint8_t value, uint8_t mode) = 0;
#endif
};
#endif