Method begin

examples/AllProtocolsOnLCD/LiquidCrystal.cpp:92–179

}

void LiquidCrystal::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
  if (lines > 1) {
    _displayfunction |= LCD_2LINE;
  }
  _numlines = lines;

  setRowOffsets(0x00, 0x40, 0x00 + cols, 0x40 + cols);

  // for some 1 line displays you can select a 10 pixel high font
  if ((dotsize != LCD_5x8DOTS) && (lines == 1)) {
    _displayfunction |= LCD_5x10DOTS;
  }

  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);

  // Do these once, instead of every time a character is drawn for speed reasons.
  for (int i=0; i<((_displayfunction & LCD_8BITMODE) ? 8 : 4); ++i)
  {
    pinMode(_data_pins[i], OUTPUT);
   }

  // 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 before 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