ESP-Ventilation/LiquidCrystal/src/LiquidCrystal.cpp

#include "LiquidCrystal.h"

#include "chip.h"
#include <cstring>

#define LOW 0
#define HIGH 1

void
delayMicroseconds (unsigned int us)
{
  uint32_t reg;
  // calculate compare value
  uint64_t cmp = (Chip_Clock_GetSystemClockRate () / 1000000)
                 * us; // One cycle equals ~72 us, thus cycle * us
  // disable RIT – compare value may only be changed when RIT is disabled
  reg = LPC_RITIMER->CTRL & 0xF;
  LPC_RITIMER->CTRL = reg & ~RIT_CTRL_TEN;
  // set compare value to RIT
  LPC_RITIMER->COMPVAL = (uint32_t)cmp;
  LPC_RITIMER->COMPVAL_H = (uint32_t) (cmp >> 32);
  // clear RIT counter (so that counting starts from zero)
  LPC_RITIMER->COUNTER = (uint32_t)0;
  LPC_RITIMER->COUNTER_H = (uint32_t) (0 >> 32);
  // enable RIT
  reg = LPC_RITIMER->CTRL & 0xF;
  LPC_RITIMER->CTRL = reg | RIT_CTRL_TEN;
  // wait until RIT Int flag is set
  while (!(LPC_RITIMER->CTRL & RIT_CTRL_INT))
    ;
  // disable RIT
  reg = LPC_RITIMER->CTRL & 0xF;
  LPC_RITIMER->CTRL = reg & ~RIT_CTRL_TEN;
  // clear RIT Int flag
  reg = LPC_RITIMER->CTRL & 0xF;
  LPC_RITIMER->CTRL = reg | RIT_CTRL_INT;
}

// 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).

LiquidCrystal::LiquidCrystal (DigitalIoPin *rs, DigitalIoPin *enable,
                              DigitalIoPin *d0, DigitalIoPin *d1,
                              DigitalIoPin *d2, DigitalIoPin *d3)
{
  rs_pin = rs;
  enable_pin = enable;

  data_pins[0] = d0;
  data_pins[1] = d1;
  data_pins[2] = d2;
  data_pins[3] = d3;

  _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;

  begin (16, 2); // default to 16x2 display
}

void
LiquidCrystal::begin (uint8_t cols, uint8_t lines, uint8_t dotsize)
{
  this->rows = lines;
  this->col = cols;
  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
  rs_pin->write (false);     // digitalWrite(_rs_pin, LOW);
  enable_pin->write (false); // digitalWrite(_enable_pin, LOW);

  // note: this port supports only 4 bit mode
  // 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
LiquidCrystal::clear ()
{
  command (LCD_CLEARDISPLAY); // clear display, set cursor position to zero
  delayMicroseconds (2000);   // this command takes a long time!
}

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

void
LiquidCrystal::print (std::string const &s)
{
  this->print (s.c_str ());
}

void
LiquidCrystal::print (const char *s)
{
  int char_counter = 0;
  while (*s && char_counter < this->col)
    {
      send (*s, HIGH);
      char_counter++;
      s++;
    }
}

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]);
    }
}

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

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

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

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

// write either command or data
void
LiquidCrystal::send (uint8_t value, uint8_t mode)
{
  rs_pin->write (mode); // digitalWrite(_rs_pin, mode);

  write4bits (value >> 4);
  write4bits (value);
}

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

void
LiquidCrystal::write4bits (uint8_t value)
{
  for (int i = 0; i < 4; i++)
    {
      data_pins[i]->write (
          (value >> i)
          & 0x01); // digitalWrite(_data_pins[i], (value >> i) & 0x01);
    }

  pulseEnable ();
}