CustomLiquidCrystal.cpp

//Downloaded from: http://playground.arduino.cc/Main/LiquidCrystal
#include "CustomLiquidCrystal.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 its in that state when a sketch starts (and the
// CustomLiquidCrystal constructor is called).

CustomLiquidCrystal::CustomLiquidCrystal(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);
}

CustomLiquidCrystal::CustomLiquidCrystal(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);
}

CustomLiquidCrystal::CustomLiquidCrystal(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);
}

CustomLiquidCrystal::CustomLiquidCrystal(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);
}

CustomLiquidCrystal::CustomLiquidCrystal(uint8_t ssPin) //SPI  ##############################
{
  initSPI(ssPin);
  //shiftRegister pins 1,2,3,4,5,6,7 represent rs, rw, enable, d4-7 in that order
  //but we are not using RW so RW it's zero or 255
  init(1, 1, 255, 3, 0, 0, 0, 0, 4, 5, 6, 7);   
}

void CustomLiquidCrystal::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);
  
  //since in initSPI constructor we set _usingSPI to true and we run it first
  //from SPI constructor, we do nothing here otherwise we set it to false
  if (_usingSpi) //SPI ######################################################
  {
    ;
  }
  else
  {
    _usingSpi = false;
  }	
}

void CustomLiquidCrystal::initSPI(uint8_t ssPin) //SPI ##########################################
{
    // initialize SPI:
	_usingSpi = true;
	_latchPin = ssPin;
	pinMode (_latchPin, OUTPUT); //just in case _latchPin is not 10 or 53 set it to output 
								 //otherwise SPI.begin() will set it to output but just in case
		
	SPI.begin(); 
	
	//set clockDivider to SPI_CLOCK_DIV2 by default which is 8MHz
	_clockDivider = SPI_CLOCK_DIV2;
	SPI.setClockDivider(_clockDivider);
	
	//set data mode to SPI_MODE0 by default
	_dataMode = SPI_MODE0;
	SPI.setDataMode(_dataMode);
	
	//set bitOrder to MSBFIRST by default
	_bitOrder = MSBFIRST; 
	SPI.setBitOrder(_bitOrder);
}

void CustomLiquidCrystal::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); 
  // 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

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

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

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

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

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

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

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

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

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

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

// Allows us to fill the first 8 CGRAM locations
// with custom characters
void CustomLiquidCrystal::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 CustomLiquidCrystal::command(uint8_t value) {
  send(value, LOW);
}

inline size_t CustomLiquidCrystal::write(uint8_t value) {
  send(value, HIGH);
  return 1; // assume sucess
}

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

// write either command or data, with automatic 4/8-bit selection
void CustomLiquidCrystal::send(uint8_t value, uint8_t mode) {
  if (_usingSpi == false)
  {
    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);
    }
  }
  else //we use SPI  ##########################################
  {
    bitWrite(_bitString, _rs_pin, mode); //set RS to mode
    spiSendOut();
    
	//we are not using RW with SPI so we are not even bothering
	//or 8BITMODE so we go straight to write4bits
    write4bits(value>>4);
    write4bits(value);    
  }
}

void CustomLiquidCrystal::pulseEnable(void) {
  if (_usingSpi == false)
  {
    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
  }
  else //we use SPI #############################################
  {
    bitWrite(_bitString, _enable_pin, LOW); 
    spiSendOut();
	delayMicroseconds(1); 
	bitWrite(_bitString, _enable_pin, HIGH); 
    spiSendOut();
	delayMicroseconds(1);    // enable pulse must be >450ns
	bitWrite(_bitString, _enable_pin, LOW); 
    spiSendOut();
	delayMicroseconds(40);   // commands need > 37us to settle
  }
}

void CustomLiquidCrystal::write4bits(uint8_t value) {
  if (_usingSpi == false)
  {
    for (int i = 0; i < 4; i++) {
      pinMode(_data_pins[i], OUTPUT);
      digitalWrite(_data_pins[i], (value >> i) & 0x01);
    }
  }
  else //we use SPI ##############################################
  {
    for (int i = 4; i < 8; i++)
	{
	  //we put the four bits in the _bit_string
	  bitWrite(_bitString, i, ((value >> (i - 4)) & 0x01)); 
	}
	//and send it out
	spiSendOut();
  }
  pulseEnable();
}

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

void CustomLiquidCrystal::spiSendOut() //SPI #############################
{
  //just in case you are using SPI for more then one device
  //set bitOrder, clockDivider and dataMode each time
  SPI.setClockDivider(_clockDivider); 
  SPI.setBitOrder(_bitOrder);
  SPI.setDataMode(_dataMode); 
  
  digitalWrite(_latchPin, LOW);
  SPI.transfer(_bitString);
  digitalWrite(_latchPin, HIGH); 
}