#include "LiquidCrystal.h" #include <stdio.h> #include <string.h> #include <inttypes.h> #include <Arduino.h> // 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(pin_t rs, pin_t rw, pin_t enable, pin_t d0, pin_t d1, pin_t d2, pin_t d3, pin_t d4, pin_t d5, pin_t d6, pin_t d7) { init(0, rs, rw, enable, d0, d1, d2, d3, d4, d5, d6, d7); } LiquidCrystal::LiquidCrystal(pin_t rs, pin_t enable, pin_t d0, pin_t d1, pin_t d2, pin_t d3, pin_t d4, pin_t d5, pin_t d6, pin_t d7) { init(0, rs, P_NC, enable, d0, d1, d2, d3, d4, d5, d6, d7); } LiquidCrystal::LiquidCrystal(pin_t rs, pin_t rw, pin_t enable, pin_t d0, pin_t d1, pin_t d2, pin_t d3) { init(1, rs, rw, enable, d0, d1, d2, d3, P_NC, P_NC, P_NC, P_NC); } LiquidCrystal::LiquidCrystal(pin_t rs, pin_t enable, pin_t d0, pin_t d1, pin_t d2, pin_t d3) { init(1, rs, P_NC, enable, d0, d1, d2, d3, P_NC, P_NC, P_NC, P_NC); } void LiquidCrystal::init(uint8_t fourbitmode, pin_t rs, pin_t rw, pin_t enable, pin_t d0, pin_t d1, pin_t d2, pin_t d3, pin_t d4, pin_t d5, pin_t d6, pin_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; if (fourbitmode) _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS; else _displayfunction = LCD_8BITMODE | LCD_1LINE | LCD_5x8DOTS; begin(16, 1); } 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 // 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); } void LiquidCrystal::setRowOffsets(int row0, int row1, int row2, int row3) { _row_offsets[0] = row0; _row_offsets[1] = row1; _row_offsets[2] = row2; _row_offsets[3] = row3; } /********** 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::setCursor(uint8_t col, uint8_t row) { const size_t max_lines = sizeof(_row_offsets) / sizeof(*_row_offsets); if ( row >= max_lines ) { row = max_lines - 1; // we count rows starting w/0 } 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, with automatic 4/8-bit selection void LiquidCrystal::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::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::write4bits(uint8_t value) { for (int i = 0; i < 4; i++) { digitalWrite(_data_pins[i], (value >> i) & 0x01); } pulseEnable(); } void LiquidCrystal::write8bits(uint8_t value) { for (int i = 0; i < 8; i++) { digitalWrite(_data_pins[i], (value >> i) & 0x01); } pulseEnable(); }