// --------------------------------------------------------------------------- // Created by Francisco Malpartida on 20/08/11. // Copyright 2011 - Under creative commons license 3.0: // Attribution-ShareAlike CC BY-SA // // This software is furnished "as is", without technical support, and with no // warranty, express or implied, as to its usefulness for any purpose. // // Thread Safe: No // Extendable: Yes // // @file LCD.cpp // This file implements a basic liquid crystal library that comes as standard // in the Arduino SDK. // // @brief // This is a basic implementation of the HD44780 library of the // Arduino SDK. This library is a refactored version of the one supplied // in the Arduino SDK in such a way that it simplifies its extension // to support other mechanism to communicate to LCDs such as I2C, Serial, SR, ... // The original library has been reworked in such a way that this will be // the base class implementing all generic methods to command an LCD based // on the Hitachi HD44780 and compatible chipsets. // // This base class is a pure abstract class and needs to be extended. As reference, // it has been extended to drive 4 and 8 bit mode control, LCDs and I2C extension // backpacks such as the I2CLCDextraIO using the PCF8574* I2C IO Expander ASIC. // // // @version API 1.1.0 // // 2012.03.29 bperrybap - changed comparision to use LCD_5x8DOTS rather than 0 // @author F. Malpartida - fmalpartida@gmail.com // --------------------------------------------------------------------------- #include #include #include #if (ARDUINO < 100) #include #else #include #endif #include "LCD.h" // CLASS CONSTRUCTORS // --------------------------------------------------------------------------- // Constructor LCD::LCD () { } // PUBLIC METHODS // --------------------------------------------------------------------------- // 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). // A call to begin() will reinitialize the LCD. // void LCD::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) { if (lines > 1) { _displayfunction |= LCD_2LINE; } _numlines = lines; _cols = cols; // for some 1 line displays you can select a 10 pixel high font // ------------------------------------------------------------ if ((dotsize != LCD_5x8DOTS) && (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 before 4.5V so we'll wait // 50 // --------------------------------------------------------------------------- delay (100); // 100ms delay //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 send(0x03, FOUR_BITS); delayMicroseconds(4500); // wait min 4.1ms // second try send ( 0x03, FOUR_BITS ); delayMicroseconds(4500); // wait min 4.1ms // third go! send( 0x03, FOUR_BITS ); delayMicroseconds(150); // finally, set to 4-bit interface send ( 0x02, FOUR_BITS ); } 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 the LCD clear(); // Initialize to default text direction (for romance languages) _displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT; // set the entry mode command(LCD_ENTRYMODESET | _displaymode); backlight(); } // Common LCD Commands // --------------------------------------------------------------------------- void LCD::clear() { command(LCD_CLEARDISPLAY); // clear display, set cursor position to zero delayMicroseconds(HOME_CLEAR_EXEC); // this command is time consuming } void LCD::home() { command(LCD_RETURNHOME); // set cursor position to zero delayMicroseconds(HOME_CLEAR_EXEC); // This command is time consuming } void LCD::setCursor(uint8_t col, uint8_t row) { const byte row_offsetsDef[] = { 0x00, 0x40, 0x14, 0x54 }; // For regular LCDs const byte row_offsetsLarge[] = { 0x00, 0x40, 0x10, 0x50 }; // For 16x4 LCDs if ( row >= _numlines ) { row = _numlines-1; // rows start at 0 } // 16x4 LCDs have special memory map layout // ---------------------------------------- if ( _cols == 16 && _numlines == 4 ) { command(LCD_SETDDRAMADDR | (col + row_offsetsLarge[row])); } else { command(LCD_SETDDRAMADDR | (col + row_offsetsDef[row])); } } // Turn the display on/off void LCD::noDisplay() { _displaycontrol &= ~LCD_DISPLAYON; command(LCD_DISPLAYCONTROL | _displaycontrol); } void LCD::display() { _displaycontrol |= LCD_DISPLAYON; command(LCD_DISPLAYCONTROL | _displaycontrol); } // Turns the underline cursor on/off void LCD::noCursor() { _displaycontrol &= ~LCD_CURSORON; command(LCD_DISPLAYCONTROL | _displaycontrol); } void LCD::cursor() { _displaycontrol |= LCD_CURSORON; command(LCD_DISPLAYCONTROL | _displaycontrol); } // Turns on/off the blinking cursor void LCD::noBlink() { _displaycontrol &= ~LCD_BLINKON; command(LCD_DISPLAYCONTROL | _displaycontrol); } void LCD::blink() { _displaycontrol |= LCD_BLINKON; command(LCD_DISPLAYCONTROL | _displaycontrol); } // These commands scroll the display without changing the RAM void LCD::scrollDisplayLeft(void) { command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT); } void LCD::scrollDisplayRight(void) { command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT); } // This is for text that flows Left to Right void LCD::leftToRight(void) { _displaymode |= LCD_ENTRYLEFT; command(LCD_ENTRYMODESET | _displaymode); } // This is for text that flows Right to Left void LCD::rightToLeft(void) { _displaymode &= ~LCD_ENTRYLEFT; command(LCD_ENTRYMODESET | _displaymode); } // This method moves the cursor one space to the right void LCD::moveCursorRight(void) { command(LCD_CURSORSHIFT | LCD_CURSORMOVE | LCD_MOVERIGHT); } // This method moves the cursor one space to the left void LCD::moveCursorLeft(void) { command(LCD_CURSORSHIFT | LCD_CURSORMOVE | LCD_MOVELEFT); } // This will 'right justify' text from the cursor void LCD::autoscroll(void) { _displaymode |= LCD_ENTRYSHIFTINCREMENT; command(LCD_ENTRYMODESET | _displaymode); } // This will 'left justify' text from the cursor void LCD::noAutoscroll(void) { _displaymode &= ~LCD_ENTRYSHIFTINCREMENT; command(LCD_ENTRYMODESET | _displaymode); } // Write to CGRAM of new characters void LCD::createChar(uint8_t location, uint8_t charmap[]) { location &= 0x7; // we only have 8 locations 0-7 command(LCD_SETCGRAMADDR | (location << 3)); delayMicroseconds(30); for (int i=0; i<8; i++) { write(charmap[i]); // call the virtual write method delayMicroseconds(40); } } // // Switch on the backlight void LCD::backlight ( void ) { setBacklight(255); } // // Switch off the backlight void LCD::noBacklight ( void ) { setBacklight(0); } // // Switch fully on the LCD (backlight and LCD) void LCD::on ( void ) { display(); backlight(); } // // Switch fully off the LCD (backlight and LCD) void LCD::off ( void ) { noBacklight(); noDisplay(); } // General LCD commands - generic methods used by the rest of the commands // --------------------------------------------------------------------------- void LCD::command(uint8_t value) { send(value, COMMAND); } #if (ARDUINO < 100) void LCD::write(uint8_t value) { send(value, DATA); } #else size_t LCD::write(uint8_t value) { send(value, DATA); return 1; // assume OK } #endif