/*
* Arduino library to drive an LCD display that uses a Toshiba T6A34 controller chip
* Based on the structure of the standard LiquidCrystal.cpp routines for the Hitachi HD44780 chip
* The T6A34 commands are basically the same as the HD44780, so this is usable as a replacement
* for the LiquidCrystal library, but compatibility hasn't been extensively tested.
* 
* Thanks to the authors of the standard LiquidCrystal.cpp HD44780 library.
* Author Tony Wills
* Licensed CC-BY-SA
*
* 20181119 Initial release version 1.00
* 20181120 Ver 1.10 added LED control
* 20181217 Ver 1.11 fixed createChar() to direct data input back to screen ram
* see http://www.arduino.scorchingbay.nz (or an archive.org copy) for more information
*/

#include "LiquidCrystal_t6a34.h"

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <TimerOne.h>

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

// When the display is reset, it is configured as follows:
//
// 1. Display clear
// 2. Function set: 
//    BL = 1; Blink mode is all pixels on 
//    N = 0; 1-line display 
//    F = 0; 5x7 dot character font 
// 3. Entry mode set: 
//    I/D = 1; Increment by 1 
//    S = 0; No shift 
// 4. Display on/off control: 
//    D = 0; Display off 
//    C = 0; Cursor off 
//    B = 0; Blinking off 
//

LiquidCrystal::LiquidCrystal(uint8_t data_in, uint8_t data_out, uint8_t clk)
{
  init(data_in, data_out, clk);
}

LiquidCrystal::LiquidCrystal(uint8_t data_in, uint8_t clk)
{
  init(data_in, 255, clk);
}

void LiquidCrystal::init(uint8_t data_in, uint8_t data_out, uint8_t clk)
{
  _sid_pin = data_in;
  _sod_pin = data_out;
  _sclk_pin = clk;
  
  digitalWrite(_sid_pin, HIGH);   //set high before enabling as output
  pinMode(_sid_pin, OUTPUT);
  //delayMicroseconds(2);           //ensure data settled as high before enabling clock so don't get random start bits
  //for (int i=0; i<1000; i++) {};
  
  digitalWrite(_sclk_pin, HIGH);  //set high before enabling as output
  pinMode(_sclk_pin, OUTPUT);
  //setup clock for t6a34 lcd chip
  Timer1.initialize(period);                          //initialize timer1
  Timer1.pwm(_sclk_pin, duty);                        //setup pwm on _sclk_pin, 50% duty cycle
  Timer1.start();
  
  //delay(2000);
  if (_sod_pin != 255) {
    pinMode(_sod_pin, INPUT);
  }
 	  
  _displayfunction = LCD_BLINKMODE | LCD_1LINE | LCD_5x7DOTS;
  command(LCD_FUNCTIONSET | _displayfunction);  
  
}


void LiquidCrystal::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;
  }

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

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

void LiquidCrystal::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 LiquidCrystal::noDisplay() {
  _displaycontrol &= ~LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void LiquidCrystal::display() {
  _displaycontrol |= LCD_DISPLAYON;
  command(LCD_DISPLAYCONTROL | _displaycontrol);
}

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

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

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

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

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

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

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

// Allows us to fill the first 8 CGRAM locations
// with custom characters
void LiquidCrystal::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(0,0); // direct data input back to screen ram
}

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

inline void LiquidCrystal::command(uint8_t value) {
  send(value, IR_WRITE);
  delayMicroseconds(cmd_delay);
}

inline size_t LiquidCrystal::write(uint8_t value) {
  send(value, DR_WRITE);
  return 1; // assume sucess
  delayMicroseconds(cmd_delay);
}

void LiquidCrystal::setLeds(uint16_t value)
{
  send((value & 0xFF), LER1_WRITE);
  send(((value >> 8) & 0xFF), LER2_WRITE);
}

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

// write either command or data
void LiquidCrystal::send(uint8_t value, uint8_t mode) {
  

  Timer1.disablePwm(_sclk_pin);          //Turn off pwm clock so we can manually clock data

  //write start bits  
  digitalWrite(_sid_pin, 0);     //3 zero bits as start
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);

  //write rs bits
  digitalWrite(_sid_pin, mode & 0x01);         //rs1 first
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);
  digitalWrite(_sid_pin, (mode >> 1) & 0x01);  //rs2 second
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);

  //write the command/data byte
  for (int i = 0; i < 8; i++) {
    digitalWrite(_sid_pin, (value >> i) & 0x01);  //lsb first
    digitalWrite(_sclk_pin, LOW);
    digitalWrite(_sclk_pin, HIGH);
  } 
  //write out 3 explicit stop bits
  digitalWrite(_sid_pin, 1);      //3 one bits as stop
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);
  digitalWrite(_sclk_pin, LOW);
  digitalWrite(_sclk_pin, HIGH);

  //turn on pwm clock to keep LCD alive
  Timer1.initialize(period);      //initialize timer1
  Timer1.pwm(_sclk_pin, duty); 
  Timer1.start();
}