/*
* Arduino library to drive an LCD display as found in the Epson MX300/310 printers.
* Based on the structure of the standard LiquidCrystal.cpp routines for the Hitachi HD44780 chip
* The commands seem to be a subset of the HD44780, so this is usable as a replacement
*  for the LiquidCrystal library, but compatibility hasn't been extensively tested.
* 
* I haven't yet discovered exactly which controller chip these displays contain.
* They have a 14 pin, 0.04” spaced, PCB flex cable, connected as follows:
*  1	R/W
*  2	RS
*  3	E
*  4	DB0
*  5	DB1
*  6	DB2
*  7	DB3
*  8	DB4
*  9	DB5
* 10	DB6
* 11	DB7
* 12	Gnd
* 13	Vdd
* 14	Vlcd
*
* It has the normal HD44780 control lines and optional 4/8 bit operation.
* All control and data lines are 3.3V so a 3.3V Arduino is needed
*  or the use of level converters are necessary.
* There are a couple of extra commands to mirror the display, and the two
* rows of characters have no blank separator row between so that double height
* fonts can be devised using the programmable characters.
* Example double sized fonts are selectable with compiler directives in the ".h" file.
*
* The double height and scrolling routines should basically work with other HD44780
* compatible displays, but will probably break for more than 2 line displays.
*
* Thanks to the authors of the standard LiquidCrystal.cpp HD44780 library.
* Thanks to Michael Pilcher for a versatile rounded font
* Author Tony Wills
* Licensed CC-BY-SA
*
* 20190113 Initial release version 1.00
* 20190119 Version 1.01
*   Fixed scroll routine, added non mx300 specific font
*
* see http://www.arduino.scorchingbay.nz (or an archive.org copy) for more information
*/

#include "LiquidCrystal_mx300.h"

#include <stdio.h>
#include <string.h>
#include <inttypes.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 it is in that state when a sketch starts (and the
// LiquidCrystal constructor is called).

LiquidCrystal_mx300::LiquidCrystal_mx300(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)
{
  init(0, rs, rw, enable, d0, d1, d2, d3, d4, d5, d6, d7);
}

LiquidCrystal_mx300::LiquidCrystal_mx300(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)
{
  init(0, rs, 255, enable, d0, d1, d2, d3, d4, d5, d6, d7);
}

LiquidCrystal_mx300::LiquidCrystal_mx300(uint8_t rs, uint8_t rw, uint8_t enable,
			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
{
  init(1, rs, rw, enable, d0, d1, d2, d3, 0, 0, 0, 0);
}

LiquidCrystal_mx300::LiquidCrystal_mx300(uint8_t rs,  uint8_t enable,
			     uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3)
{
  init(1, rs, 255, enable, d0, d1, d2, d3, 0, 0, 0, 0);
}


void LiquidCrystal_mx300::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)
{
  _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; 

  pinMode(_rs_pin, OUTPUT);
  // we can save 1 pin by not using RW. Indicate by passing 255 instead of pin#
  if (_rw_pin != 255) { 
    pinMode(_rw_pin, OUTPUT);
  }
  pinMode(_enable_pin, OUTPUT);
  
  if (fourbitmode)
    _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
  else 
    _displayfunction = LCD_8BITMODE | LCD_1LINE | LCD_5x8DOTS;
  
  begin(16, 1);

  
}

void LiquidCrystal_mx300::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
  if (lines > 1) {
    _displayfunction |= LCD_2LINE;
  }
  _numlines = lines;
  _numcols = cols;
  _autoscroll = false;
  _shifted = false;
  _writebig = false;
  _currcol = 0;
  _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); 
  // Now we pull both RS and R/W low to begin commands
  digitalWrite(_rs_pin, LOW);
  digitalWrite(_enable_pin, LOW);
  if (_rw_pin != 255) { 
    digitalWrite(_rw_pin, LOW);
  }
  
  //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

    // 
    command(LCD_FUNCTIONSET | _displayfunction);
    delayMicroseconds(150);

    // 
    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);

  // Setup the character segments used by the bigfont
  for (int n = 0; n < 8; n++)
    createChar(n, _charpixels[n]);
}

/********** high level commands, for the user! */
void LiquidCrystal_mx300::clear()
{
  command(LCD_CLEARDISPLAY);  // clear display, set cursor position to zero
  _currcol = 0;
  _currline = 0;
  _shifted = false;
  delayMicroseconds(2000);  // this command takes a long time!
}

void LiquidCrystal_mx300::home()
{
  command(LCD_RETURNHOME);  // set cursor position to zero
  _currcol = 0;
  _currline = 0;
  _shifted = false;
  delayMicroseconds(2000);  // this command takes a long time!
}

void LiquidCrystal_mx300::setCursor(uint8_t col, uint8_t row, bool update)
{
  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]));
  if (update) { // only update our cursor location if told too
    _currcol = col;
    _currline = row;
  }
}


// Turn the display on/off (quickly)
void LiquidCrystal_mx300::noDisplay() {
  _displaycontrol &= ~LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_mx300::display() {
  _displaycontrol |= LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// Turns the underline cursor on/off
void LiquidCrystal_mx300::noCursor() {
  _displaycontrol &= ~LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_mx300::cursor() {
  _displaycontrol |= LCD_CURSORON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// Turn on and off the blinking cursor
void LiquidCrystal_mx300::noBlink() {
  _displaycontrol &= ~LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal_mx300::blink() {
  _displaycontrol |= LCD_BLINKON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

// These commands scroll the display without changing the RAM
void LiquidCrystal_mx300::scrollDisplayLeft(void) {
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
  _shifted = true;
}
void LiquidCrystal_mx300::scrollDisplayRight(void) {
  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
  _shifted = true;
}

// This is for text that flows Left to Right
void LiquidCrystal_mx300::leftToRight(void) {
  _displaymode |= LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This is for text that flows Right to Left
void LiquidCrystal_mx300::rightToLeft(void) {
  _displaymode &= ~LCD_ENTRYLEFT;
  command(LCD_ENTRYMODESET | _displaymode);
}

// This will 'right shift' text from the cursor
void LiquidCrystal_mx300::autoscroll(void) {
  //_displaymode |= LCD_ENTRYSHIFTINCREMENT;
  //command(LCD_ENTRYMODESET | _displaymode);
  _autoscroll = true;
}

// This will 'left shift' text from the cursor
void LiquidCrystal_mx300::noAutoscroll(void) {
  //_displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
  //command(LCD_ENTRYMODESET | _displaymode);
  _autoscroll = false;
}

// Allows us to fill the first 8 CGRAM locations
// with custom characters
void LiquidCrystal_mx300::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]);
  }
  setCursor(_currcol,_currline); // redirect data input back to display ram
}

// Turn off printing large characters
void LiquidCrystal_mx300::clearBigfont(void) {
  _writebig = false;
}
// Turn on printing large characters
void LiquidCrystal_mx300::setBigfont(void) {
  _writebig = true;
}

void LiquidCrystal_mx300::mirrorHorz() {
  command(LCD_MIRHORZ);
}
void LiquidCrystal_mx300::mirrorVert() {
  command(LCD_MIRVERT);
}
void LiquidCrystal_mx300::rotate180() {
  command(LCD_ROTATE);
}
void LiquidCrystal_mx300::noMirror() {
  command(LCD_NORMAL);
}

/*********** mid level commands, for sending data/cmds */

inline void LiquidCrystal_mx300::command(uint8_t value) {
  send(value, LOW);
}

void LiquidCrystal_mx300::writeBig(uint8_t upper, uint8_t lower) {
  // Write two characters in one column to form part of bigfont character
  if (_shifted & _autoscroll ) scrollDisplayLeft();
  setCursor(_currcol % 40, 0, false);
  send(upper, HIGH);
  setCursor(_currcol % 40, 1, false);
  send(lower, HIGH);
  _currcol++;
  if ((_currcol >= _numcols) & _autoscroll ) _shifted = true;
}

inline size_t LiquidCrystal_mx300::write(uint8_t value) {
  // "_shifted" keeps track of whether we've already printed past the end of the visible display area
  //   - if so we leftshift the display with each new character.
  //     This allows us to print _numcols visible characters then start scrolling, and continue scrolling forever
  //     even once the cursor has wrapped around to 0 (only 40 characters in LCD line buffer)
  if (!_writebig) {
    // Just write normal character but keep track of column in case we will be scrolling
    if (_shifted & _autoscroll ) scrollDisplayLeft();
    send(value, HIGH);
    _currcol++;
    if ((_currcol >= _numcols) & _autoscroll ) _shifted = true;
    if ((_currcol % 40) == 0) setCursor(0, _currline, true);
  } else {
    // Write two halves of the bigfont character unless it is a blank column
    //  (allows for variable width characters)
    if ((value >= ' ') & (value < 128)) {  // have only defined ASCII characters 32 to 127
      for (int i = 0; i < 4; i++ ) { // upto 4 columns per character
        if ((_bigFont[value - 32][i] != 32) | (_bigFont[value-32][i+4] != 32)) {  //not a blank column in character
          writeBig(_bigFont[value - 32][i], _bigFont[value - 32][i+4]);
        }
      }

      // If the character to be printed was a space we didn't actually print anything, so print one now
      if (value==' ') writeBig(' ', ' ');

      // Print a blank gap between characters
      writeBig(' ', ' ');
    }
    setCursor(_currcol % 40, _currline, true);
  }
  return 1; // assume success
}

/************ low level data pushing commands **********/

// write either command or data, with automatic 4/8-bit selection
void LiquidCrystal_mx300::send(uint8_t value, uint8_t mode) {
  digitalWrite(_rs_pin, mode);

  // if there is a RW pin indicated, set it low to Write
  if (_rw_pin != 255) { 
    digitalWrite(_rw_pin, LOW);
  }
  
  if (_displayfunction & LCD_8BITMODE) {
    write8bits(value); 
  } else {
    write4bits(value>>4);
    write4bits(value);
  }
}

void LiquidCrystal_mx300::pulseEnable(void) {
  digitalWrite(_enable_pin, LOW);
  delayMicroseconds(1);    
  digitalWrite(_enable_pin, HIGH);
  delayMicroseconds(1);    // enable pulse must be >450ns
  digitalWrite(_enable_pin, LOW);
  delayMicroseconds(100);   // commands need > 37us to settle
}

void LiquidCrystal_mx300::write4bits(uint8_t value) {
  for (int i = 0; i < 4; i++) {
    pinMode(_data_pins[i], OUTPUT);
    digitalWrite(_data_pins[i], (value >> i) & 0x01);
  }
  pulseEnable();
}

void LiquidCrystal_mx300::write8bits(uint8_t value) {
  for (int i = 0; i < 8; i++) {
    pinMode(_data_pins[i], OUTPUT);
    digitalWrite(_data_pins[i], (value >> i) & 0x01);
  }
  pulseEnable();
}