291 lines
7.9 KiB
C++
291 lines
7.9 KiB
C++
// ---------------------------------------------------------------------------
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// Created by Francisco Malpartida on 20/08/11.
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// Copyright 2011 - Under creative commons license 3.0:
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// Attribution-ShareAlike CC BY-SA
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//
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// This software is furnished "as is", without technical support, and with no
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// warranty, express or implied, as to its usefulness for any purpose.
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//
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// Thread Safe: No
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// Extendable: Yes
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//
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// @file LiquidCrystal_I2C.c
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// This file implements a basic liquid crystal library that comes as standard
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// in the Arduino SDK but using an I2C IO extension board.
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//
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// @brief
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// This is a basic implementation of the LiquidCrystal library of the
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// Arduino SDK. The original library has been reworked in such a way that
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// this class implements the all methods to command an LCD based
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// on the Hitachi HD44780 and compatible chipsets using I2C extension
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// backpacks such as the I2CLCDextraIO with the PCF8574* I2C IO Expander ASIC.
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//
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// The functionality provided by this class and its base class is identical
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// to the original functionality of the Arduino LiquidCrystal library.
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//
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//
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//
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// @author F. Malpartida - fmalpartida@gmail.com
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// ---------------------------------------------------------------------------
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#if (ARDUINO < 100)
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#include <WProgram.h>
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#else
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#include <Arduino.h>
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#endif
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#include <inttypes.h>
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#include "I2CIO.h"
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#include "LiquidCrystal_I2C.h"
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// CONSTANT definitions
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// ---------------------------------------------------------------------------
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// flags for backlight control
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/*!
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@defined
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@abstract LCD_NOBACKLIGHT
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@discussion NO BACKLIGHT MASK
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*/
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#define LCD_NOBACKLIGHT 0x00
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/*!
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@defined
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@abstract LCD_BACKLIGHT
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@discussion BACKLIGHT MASK used when backlight is on
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*/
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#define LCD_BACKLIGHT 0xFF
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// Default library configuration parameters used by class constructor with
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// only the I2C address field.
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// ---------------------------------------------------------------------------
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/*!
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@defined
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@abstract Enable bit of the LCD
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@discussion Defines the IO of the expander connected to the LCD Enable
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*/
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#define EN 6 // Enable bit
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/*!
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@defined
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@abstract Read/Write bit of the LCD
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@discussion Defines the IO of the expander connected to the LCD Rw pin
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*/
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#define RW 5 // Read/Write bit
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/*!
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@defined
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@abstract Register bit of the LCD
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@discussion Defines the IO of the expander connected to the LCD Register select pin
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*/
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#define RS 4 // Register select bit
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/*!
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@defined
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@abstract LCD dataline allocation this library only supports 4 bit LCD control
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mode.
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@discussion D4, D5, D6, D7 LCD data lines pin mapping of the extender module
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*/
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#define D4 0
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#define D5 1
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#define D6 2
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#define D7 3
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// CONSTRUCTORS
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// ---------------------------------------------------------------------------
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LiquidCrystal_I2C::LiquidCrystal_I2C( uint8_t lcd_Addr )
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{
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config(lcd_Addr, EN, RW, RS, D4, D5, D6, D7);
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}
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LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t backlighPin,
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t_backlighPol pol = POSITIVE)
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{
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config(lcd_Addr, EN, RW, RS, D4, D5, D6, D7);
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setBacklightPin(backlighPin, pol);
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}
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LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
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uint8_t Rs)
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{
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config(lcd_Addr, En, Rw, Rs, D4, D5, D6, D7);
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}
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LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
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uint8_t Rs, uint8_t backlighPin,
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t_backlighPol pol = POSITIVE)
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{
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config(lcd_Addr, En, Rw, Rs, D4, D5, D6, D7);
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setBacklightPin(backlighPin, pol);
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}
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LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
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uint8_t Rs, uint8_t d4, uint8_t d5,
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uint8_t d6, uint8_t d7 )
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{
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config(lcd_Addr, En, Rw, Rs, d4, d5, d6, d7);
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}
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LiquidCrystal_I2C::LiquidCrystal_I2C(uint8_t lcd_Addr, uint8_t En, uint8_t Rw,
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uint8_t Rs, uint8_t d4, uint8_t d5,
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uint8_t d6, uint8_t d7, uint8_t backlighPin,
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t_backlighPol pol = POSITIVE )
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{
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config(lcd_Addr, En, Rw, Rs, d4, d5, d6, d7);
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setBacklightPin(backlighPin, pol);
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}
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// PUBLIC METHODS
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// ---------------------------------------------------------------------------
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//
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// begin
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void LiquidCrystal_I2C::begin(uint8_t cols, uint8_t lines, uint8_t dotsize)
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{
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init(); // Initialise the I2C expander interface
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LCD::begin ( cols, lines, dotsize );
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}
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// User commands - users can expand this section
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//----------------------------------------------------------------------------
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// Turn the (optional) backlight off/on
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//
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// setBacklightPin
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void LiquidCrystal_I2C::setBacklightPin ( uint8_t value, t_backlighPol pol = POSITIVE )
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{
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_backlightPinMask = ( 1 << value );
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_polarity = pol;
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setBacklight(BACKLIGHT_OFF);
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}
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//
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// setBacklight
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void LiquidCrystal_I2C::setBacklight( uint8_t value )
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{
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// Check if backlight is available
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// ----------------------------------------------------
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if ( _backlightPinMask != 0x0 )
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{
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// Check for polarity to configure mask accordingly
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// ----------------------------------------------------------
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if (((_polarity == POSITIVE) && (value > 0)) ||
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((_polarity == NEGATIVE ) && ( value == 0 )))
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{
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_backlightStsMask = _backlightPinMask & LCD_BACKLIGHT;
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}
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else
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{
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_backlightStsMask = _backlightPinMask & LCD_NOBACKLIGHT;
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}
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_i2cio.write( _backlightStsMask );
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}
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}
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// PRIVATE METHODS
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// ---------------------------------------------------------------------------
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//
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// init
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int LiquidCrystal_I2C::init()
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{
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int status = 0;
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// initialize the backpack IO expander
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// and display functions.
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// ------------------------------------------------------------------------
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if ( _i2cio.begin ( _Addr ) == 1 )
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{
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_i2cio.portMode ( OUTPUT ); // Set the entire IO extender to OUTPUT
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_displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
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status = 1;
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_i2cio.write(0); // Set the entire port to LOW
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}
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return ( status );
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}
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//
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// config
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void LiquidCrystal_I2C::config (uint8_t lcd_Addr, uint8_t En, uint8_t Rw, uint8_t Rs,
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uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7 )
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{
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_Addr = lcd_Addr;
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_backlightPinMask = 0;
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_backlightStsMask = LCD_NOBACKLIGHT;
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_polarity = POSITIVE;
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_En = ( 1 << En );
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_Rw = ( 1 << Rw );
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_Rs = ( 1 << Rs );
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// Initialise pin mapping
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_data_pins[0] = ( 1 << d4 );
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_data_pins[1] = ( 1 << d5 );
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_data_pins[2] = ( 1 << d6 );
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_data_pins[3] = ( 1 << d7 );
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}
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// low level data pushing commands
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//----------------------------------------------------------------------------
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//
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// send - write either command or data
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void LiquidCrystal_I2C::send(uint8_t value, uint8_t mode)
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{
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// No need to use the delay routines since the time taken to write takes
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// longer that what is needed both for toggling and enable pin an to execute
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// the command.
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if ( mode == FOUR_BITS )
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{
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write4bits( (value & 0x0F), COMMAND );
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}
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else
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{
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write4bits( (value >> 4), mode );
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write4bits( (value & 0x0F), mode);
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}
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}
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//
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// write4bits
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void LiquidCrystal_I2C::write4bits ( uint8_t value, uint8_t mode )
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{
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uint8_t pinMapValue = 0;
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// Map the value to LCD pin mapping
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// --------------------------------
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for ( uint8_t i = 0; i < 4; i++ )
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{
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if ( ( value & 0x1 ) == 1 )
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{
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pinMapValue |= _data_pins[i];
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}
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value = ( value >> 1 );
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}
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// Is it a command or data
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// -----------------------
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if ( mode == DATA )
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{
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mode = _Rs;
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}
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pinMapValue |= mode | _backlightStsMask;
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pulseEnable ( pinMapValue );
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}
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//
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// pulseEnable
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void LiquidCrystal_I2C::pulseEnable (uint8_t data)
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{
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_i2cio.write (data | _En); // En HIGH
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_i2cio.write (data & ~_En); // En LOW
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} |