/* Copyright 2009-2011 Oleg Mazurov, Circuits At Home, http://www.circuitsathome.com */
//this code is heavily borrowed from official Arduino source v.0017
// link to original http://code.google.com/p/arduino/source/browse/trunk/hardware/libraries/LiquidCrystal/LiquidCrystal.cpp
#include "Max_LCD.h"
#include "Max3421e.h"

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include "WProgram.h"

// 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 it's in that state when a sketch starts

// pin definition and set/clear

#define RS  0x04    // RS pin
#define E   0x08    // E pin

#define SET_RS  lcdPins |= RS
#define CLR_RS  lcdPins &= ~RS
#define SET_E   lcdPins |= E
#define CLR_E   lcdPins &= ~E

#define SENDlcdPins()   MAX3421E::gpioWr( lcdPins )
    
#define LCD_sendcmd(a)  {   CLR_RS;             \
                            sendbyte(a);    \
                        }
 
#define LCD_sendchar(a) {   SET_RS;             \
                            sendbyte(a);    \
                        }
                            
static byte lcdPins;    //copy of LCD pins

Max_LCD::Max_LCD()
{
    lcdPins = 0;
}


void Max_LCD::init()
{
    _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
 
 //   MAX3421E::gpioWr(0x55);
 
  begin(16, 1);  
}

void Max_LCD::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;
  }

  // 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);
  lcdPins = 0x30;
  SET_E;
  SENDlcdPins();
  CLR_E;
  SENDlcdPins();
  delayMicroseconds(10000); // wait min 4.1ms
  //second try
  SET_E;
  SENDlcdPins();
  CLR_E;
  SENDlcdPins();
  delayMicroseconds(10000); // wait min 4.1ms
  // third go!
  SET_E;
  SENDlcdPins();
  CLR_E;
  SENDlcdPins();
  delayMicroseconds(10000);
  // finally, set to 4-bit interface
    lcdPins = 0x20;
    //SET_RS;
    SET_E;
    SENDlcdPins();
    //CLR_RS;
    CLR_E;
    SENDlcdPins();
    delayMicroseconds(10000);
  // 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, for the user! */
void Max_LCD::clear()
{
  command(LCD_CLEARDISPLAY);  // clear display, set cursor position to zero
  delayMicroseconds(2000);  // this command takes a long time!
}

void Max_LCD::home()
{
  command(LCD_RETURNHOME);  // set cursor position to zero
  delayMicroseconds(2000);  // this command takes a long time!
}

void Max_LCD::setCursor(uint8_t col, uint8_t row)
{
  int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
  if ( row > _numlines ) {
    row = _numlines-1;    // we count rows starting w/0
  }
 
  command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
}

// Turn the display on/off (quickly)
void Max_LCD::noDisplay() {
  _displaycontrol &= ~LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void Max_LCD::display() {
  _displaycontrol |= LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// Turns the underline cursor on/off
void Max_LCD::noCursor() {
  _displaycontrol &= ~LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void Max_LCD::cursor() {
  _displaycontrol |= LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}


// Turn on and off the blinking cursor
void Max_LCD::noBlink() {
  _displaycontrol &= ~LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void Max_LCD::blink() {
  _displaycontrol |= LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// These commands scroll the display without changing the RAM
void Max_LCD::scrollDisplayLeft(void) {
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
}
void Max_LCD::scrollDisplayRight(void) {
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}

// This is for text that flows Left to Right
void Max_LCD::leftToRight(void) {
  _displaymode |= LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This is for text that flows Right to Left
void Max_LCD::rightToLeft(void) {
  _displaymode &= ~LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This will 'right justify' text from the cursor
void Max_LCD::autoscroll(void) {
  _displaymode |= LCD_ENTRYSHIFTINCREMENT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This will 'left justify' text from the cursor
void Max_LCD::noAutoscroll(void) {
  _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// Allows us to fill the first 8 CGRAM locations
// with custom characters
void Max_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]);
  }
}

/*********** mid level commands, for sending data/cmds */

inline void Max_LCD::command(uint8_t value) {
  LCD_sendcmd(value);
  delayMicroseconds(100);
}

inline void Max_LCD::write(uint8_t value) {
  LCD_sendchar(value);
}

void Max_LCD::sendbyte( uint8_t val )
{
    lcdPins &= 0x0f;                //prepare place for the upper nibble
    lcdPins |= ( val & 0xf0 );      //copy upper nibble to LCD variable
    SET_E;                          //send
    SENDlcdPins();
    delayMicroseconds(2);  
    CLR_E;
    delayMicroseconds(2);
    SENDlcdPins();
    lcdPins &= 0x0f;                    //prepare place for the lower nibble
    lcdPins |= ( val << 4 ) & 0xf0;    //copy lower nibble to LCD variable
    SET_E;                              //send
    SENDlcdPins();  
    CLR_E;
    SENDlcdPins();
    delayMicroseconds(100);
}