LiquidCrystalExt.cpp

/* This is the implementation of LiquidCrystalExt library.
 *
 * Copyright (C) 2011 Artem Borisovskiy (bytefu@gmail.com), http://robocraft.ru
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "LiquidCrystalExt.h"

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include "LineDriver.h"

#if defined(ARDUINO) && ARDUINO >= 100
  #include "Arduino.h"
#else
  #include "WProgram.h"
#endif

/* When the display powers up, it is configured as follows:
 *
 * 1. Display clear
 * 2. Function set: 
 *    DL = 1; 8-bit interface data 
 *    N = 0; 1-line display 
 *    F = 0; 5x8 dot character font 
 * 3. Display on/off control: 
 *    D = 0; Display off 
 *    C = 0; Cursor off 
 *    B = 0; Blinking off 
 * 4. Entry mode set: 
 *    I/D = 1; Increment by 1 
 *    S = 0; No shift 
 *
 * Note, however, that resetting the Arduino doesn't reset the LCD, so we
 * can't assume that its in that state when a sketch starts (and the
 * LiquidCrystal constructor is called).
 */

void LiquidCrystalBase::begin(uint8_t cols, uint8_t lines, uint8_t dotsize)
{
  if (lines > 1)
    _displayfunction |= LCD_2LINE;

  _numlines = lines;
  _currline = 0;

  /* For some 1 line displays you can select a 10 pixel high font */
  if ((dotsize != 0) && (lines == 1))
    _displayfunction |= LCD_5x10DOTS;

  config();

  /* Put the LCD into 4 bit or 8 bit mode */
  if (! (_displayfunction & LCD_8BITMODE))
  {
    /* This is according to the hitachi HD44780 datasheet figure 24, pg 46 */

    /* We start in 8bit mode, try to set 4 bit mode */
    write4bits(0x03);
    delayMicroseconds(4500); // wait min 4.1ms

    /* Second try */
    write4bits(0x03);
    delayMicroseconds(4500); // wait min 4.1ms

    /* Third go! */
    write4bits(0x03);
    delayMicroseconds(150);

    /* Finally, set to 4-bit interface */
    write4bits(0x02);
  }
  else
  {
    /* This is according to the hitachi HD44780 datasheet page 45 figure 23 */

    /* Send function set command sequence */
    command(LCD_FUNCTIONSET | _displayfunction);
    delayMicroseconds(4500);  // wait more than 4.1ms

    /* Second try */
    command(LCD_FUNCTIONSET | _displayfunction);
    delayMicroseconds(150);

    /* Third go */
    command(LCD_FUNCTIONSET | _displayfunction);
  }

  /* Finally, set # lines, font size, etc. */
  command(LCD_FUNCTIONSET | _displayfunction);  

  /* Turn the display on with no cursor or blinking default */
  _displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;  
  display();

  /* Clear it off */
  clear();

  /* Initialize to default text direction (for romance languages) */
  _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
  /* Set the entry mode */
  command(LCD_ENTRYMODESET | _displaymode);
}


/*----- High level commands, user API -----*/


void LiquidCrystalBase::clear()
{
  command(LCD_CLEARDISPLAY); // clear display, set cursor position to zero
  delayMicroseconds(2000); // this command takes a long time!
}


void LiquidCrystalBase::home()
{
  command(LCD_RETURNHOME);  // set cursor position to zero
  delayMicroseconds(2000);  // this command takes a long time!
}


void LiquidCrystalBase::setCursor(uint8_t col, uint8_t row)
{
  static const int row_offsets[] = { 0x00, 0x40, 0x10, 0x50 };
  
  if (row > _numlines)
    row = _numlines - 1; // we count rows starting with zero

  command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
}


/* Turn the display on/off (quickly) */
void LiquidCrystalBase::noDisplay()
{
  _displaycontrol &= ~LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}


void LiquidCrystalBase::display()
{
  _displaycontrol |= LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}


/* Turns the underline cursor on/off */
void LiquidCrystalBase::noCursor()
{
  _displaycontrol &= ~LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}


void LiquidCrystalBase::cursor()
{
  _displaycontrol |= LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

/* Turn on and off the blinking cursor */
void LiquidCrystalBase::noBlink()
{
  _displaycontrol &= ~LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}


void LiquidCrystalBase::blink()
{
  _displaycontrol |= LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}


/* These commands scroll the display without changing the RAM */
void LiquidCrystalBase::scrollDisplayLeft(void)
{
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
}


void LiquidCrystalBase::scrollDisplayRight(void)
{
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}


/* This is for text that flows Left to Right */
void LiquidCrystalBase::leftToRight(void)
{
  _displaymode |= LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}


/* This is for text that flows Right to Left */
void LiquidCrystalBase::rightToLeft(void)
{
  _displaymode &= ~LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}


/* This will 'right justify' text from the cursor */
void LiquidCrystalBase::autoscroll(void)
{
  _displaymode |= LCD_ENTRYSHIFTINCREMENT;
  command(LCD_ENTRYMODESET | _displaymode);
}


/* This will 'left justify' text from the cursor */
void LiquidCrystalBase::noAutoscroll(void)
{
  _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
  command(LCD_ENTRYMODESET | _displaymode);
}


/* Allows us to fill the first 8 CGRAM locations with custom characters */
void LiquidCrystalBase::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]);
}


/*----- Mid level commands, for sending data/commands -----*/


void LiquidCrystalBase::command(uint8_t value)
{
  send(value, LOW);
}


#if defined(ARDUINO) && ARDUINO >= 100
size_t LiquidCrystalBase::write(uint8_t data)
#else
void LiquidCrystalBase::write(uint8_t data)
#endif
{
  send(data, HIGH);
  
  #if defined(ARDUINO) && ARDUINO >= 100
  return 1;
  #endif
}


/*----- LiquidCrystal implementation -----*/


LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
  uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7,
  LineDriver *line_driver, uint8_t backlight)
{
  init(0, rs, rw, enable, d0, d1, d2, d3, d4, d5, d6, d7, backlight, line_driver);
}


LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t enable,
  uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7,
  LineDriver *line_driver, uint8_t backlight)
{
  init(0, rs, 0xFF, enable, d0, d1, d2, d3, d4, d5, d6, d7, backlight, line_driver);
}


LiquidCrystal::LiquidCrystal(uint8_t rs, uint8_t rw, uint8_t enable,
  uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  LineDriver *line_driver, uint8_t backlight)
{
  init(1, rs, rw, enable, d0, d1, d2, d3, 0, 0, 0, 0, backlight, line_driver);
}


LiquidCrystal::LiquidCrystal(uint8_t rs,  uint8_t enable,
  uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  LineDriver *line_driver, uint8_t backlight)
{
  init(1, rs, 0xFF, enable, d0, d1, d2, d3, 0, 0, 0, 0, backlight, line_driver);
}


void LiquidCrystal::backlight(bool on)
{
  if (_backlight_pin != 0xFF)
    _pins->lineWrite(_backlight_pin, (on ? HIGH : LOW));
}


void LiquidCrystal::noBacklight()
{
  if (_backlight_pin != 0xFF)
    _pins->lineWrite(_backlight_pin, LOW);
}


void LiquidCrystal::init(uint8_t fourbitmode, uint8_t rs, uint8_t rw, uint8_t enable,
  uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3,
  uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7,
  uint8_t backlight, LineDriver *line_driver)
{
  _pins = line_driver;

  if (!_pins)
    _pins = DefaultLineDriver::getInstance();

  _rs_pin = rs;
  _rw_pin = rw;
  _enable_pin = enable;

  _data_pins[0] = d0;
  _data_pins[1] = d1;
  _data_pins[2] = d2;
  _data_pins[3] = d3; 
  _data_pins[4] = d4;
  _data_pins[5] = d5;
  _data_pins[6] = d6;
  _data_pins[7] = d7;

  _backlight_pin = backlight;

  _pins->lineConfig(_rs_pin, OUTPUT);

  // we can save 1 pin by not using RW. Indicate by passing 0xFF instead of pin#
  if (_rw_pin != 0xFF)
    _pins->lineConfig(_rw_pin, OUTPUT);

  _pins->lineConfig(_enable_pin, OUTPUT);

  if (_backlight_pin != 0xFF)
  {
    _pins->lineConfig(_backlight_pin, OUTPUT);
    _pins->lineWrite(_backlight_pin, LOW);
  }

  if (fourbitmode)
    _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
  else 
    _displayfunction = LCD_8BITMODE | LCD_1LINE | LCD_5x8DOTS;

  begin(16, 1);
}


/*----- Low level data pushing commands -----*/


void LiquidCrystal::config()
{
  for (int i = 0; i < 8; ++i)
  {
    _pins->lineConfig(_data_pins[i], OUTPUT);
    _pins->lineWrite(_data_pins[i], LOW);
  }

  /* SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
   * according to datasheet, we need at least 40ms after power rises above 2.7V
   * before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50
   */
  delayMicroseconds(50000);
  
  /* Now we pull both RS and R/W low to begin commands */
  _pins->lineWrite(_rs_pin, LOW);
  _pins->lineWrite(_enable_pin, LOW);
  
  if (_rw_pin != -1)
    _pins->lineWrite(_rw_pin, LOW);
}


/* Write either command or data, with automatic 4/8-bit selection */
void LiquidCrystal::send(uint8_t value, uint8_t mode)
{
  _pins->lineWrite(_rs_pin, mode);

  /* If there is a RW pin indicated, set it low to write */
  if (_rw_pin != 0xFF)
    _pins->lineWrite(_rw_pin, LOW);
  
  if (_displayfunction & LCD_8BITMODE)
    write8bits(value); 
  else
  {
    write4bits(value >> 4);
    write4bits(value);
  }
}


void LiquidCrystal::pulseEnable(void)
{
  _pins->lineWrite(_enable_pin, LOW);
  delayMicroseconds(1);
  _pins->lineWrite(_enable_pin, HIGH);
  delayMicroseconds(1); // enable pulse must be >450ns
  _pins->lineWrite(_enable_pin, LOW);
  delayMicroseconds(100); // commands need > 37us to settle
}


void LiquidCrystal::write4bits(uint8_t value)
{
  for (int i = 0; i < 4; ++i)
  {
    _pins->lineConfig(_data_pins[i], OUTPUT);
    _pins->lineWrite(_data_pins[i], (value >> i) & 0x01);
  }

  pulseEnable();
}


void LiquidCrystal::write8bits(uint8_t value)
{
  for (int i = 0; i < 8; ++i)
  {
    _pins->lineConfig(_data_pins[i], OUTPUT);
    _pins->lineWrite(_data_pins[i], (value >> i) & 0x01);
  }
  
  pulseEnable();
}