Updated for more display types. Fixed memoryaddress confusion in address() method. Added new getAddress() method. Added support for UDCs, Backlight control and other features such as control through I2C and SPI port expanders and controllers with native I2C and SPI interfaces. Refactored to fix issue with pins that are default declared as NC.

Dependents:   GPSDevice TestTextLCD SD to Flash Data Transfer DrumMachine ... more

Fork of TextLCD by Simon Ford

Example

Hello World! for the TextLCD

#include "mbed.h"
#include "TextLCD.h"
 
// Host PC Communication channels
Serial pc(USBTX, USBRX); // tx, rx
 
// I2C Communication
I2C i2c_lcd(p28,p27); // SDA, SCL
 
// SPI Communication
SPI spi_lcd(p5, NC, p7); // MOSI, MISO, SCLK

//TextLCD lcd(p15, p16, p17, p18, p19, p20);                // RS, E, D4-D7, LCDType=LCD16x2, BL=NC, E2=NC, LCDTCtrl=HD44780
//TextLCD_SPI lcd(&spi_lcd, p8, TextLCD::LCD40x4);   // SPI bus, 74595 expander, CS pin, LCD Type  
TextLCD_I2C lcd(&i2c_lcd, 0x42, TextLCD::LCD20x4);  // I2C bus, PCF8574 Slaveaddress, LCD Type
//TextLCD_I2C lcd(&i2c_lcd, 0x42, TextLCD::LCD16x2, TextLCD::WS0010); // I2C bus, PCF8574 Slaveaddress, LCD Type, Device Type
//TextLCD_SPI_N lcd(&spi_lcd, p8, p9);               // SPI bus, CS pin, RS pin, LCDType=LCD16x2, BL=NC, LCDTCtrl=ST7032_3V3   
//TextLCD_I2C_N lcd(&i2c_lcd, ST7032_SA, TextLCD::LCD16x2, NC, TextLCD::ST7032_3V3); // I2C bus, Slaveaddress, LCD Type, BL=NC, LCDTCtrl=ST7032_3V3  

int main() {
    pc.printf("LCD Test. Columns=%d, Rows=%d\n\r", lcd.columns(), lcd.rows());
    
    for (int row=0; row<lcd.rows(); row++) {
      int col=0;
      
      pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));      
//      lcd.putc('-');
      lcd.putc('0' + row);      
      
      for (col=1; col<lcd.columns()-1; col++) {    
        lcd.putc('*');
      }
 
      pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));      
      lcd.putc('+');
        
    }    
    
// Show cursor as blinking character
    lcd.setCursor(TextLCD::CurOff_BlkOn);
 
// Set and show user defined characters. A maximum of 8 UDCs are supported by the HD44780.
// They are defined by a 5x7 bitpattern. 
    lcd.setUDC(0, (char *) udc_0);  // Show |>
    lcd.putc(0);    
    lcd.setUDC(1, (char *) udc_1);  // Show <|
    lcd.putc(1);    

}

Handbook page

More info is here

TextLCD.h

Committer:
wim
Date:
2013-02-04
Revision:
10:dd9b3a696acd
Parent:
9:0893d986e717
Child:
11:9ec02df863a1

File content as of revision 10:dd9b3a696acd:

/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
 * Copyright (c) 2007-2010, sford, http://mbed.org
 *               2013, WH, Updated LCD types and fixed lcd address issues
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef MBED_TEXTLCD_H
#define MBED_TEXTLCD_H

#include "mbed.h"

/** A TextLCD interface for driving 4-bit HD44780-based LCDs
 *
 * Currently supports 8x1, 8x2, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4 and 40x2 panels
 *
 * @code
 * #include "mbed.h"
 * #include "TextLCD.h"
 * 
 * TextLCD lcd(p10, p12, p15, p16, p29, p30); // rs, e, d4-d7
 * 
 * int main() {
 *     lcd.printf("Hello World!\n");
 * }
 * @endcode
 */

 
class TextLCD : public Stream {
public:

    /** LCD panel format */
    enum LCDType {
        LCD8x1,     /**<  8x1 LCD panel */    
        LCD8x2,     /**<  8x2 LCD panel */            
        LCD16x2,    /**< 16x2 LCD panel (default) */
        LCD16x2B,   /**< 16x2 LCD panel alternate addressing */
        LCD16x4,    /**< 16x4 LCD panel */        
        LCD20x2,    /**< 20x2 LCD panel */
        LCD20x4,    /**< 20x4 LCD panel */
        LCD24x2,    /**< 24x2 LCD panel */        
        LCD24x4,    /**< 24x4 LCD panel, special mode KS0078 */                
        LCD40x2     /**< 40x2 LCD panel */                
    };

    /** LCD Cursor control */
    enum LCDCursor {
        CurOn,
        CurOff
    };


    /** Create a TextLCD interface
     *
     * @param rs    Instruction/data control line
     * @param e     Enable line (clock)
     * @param d4-d7 Data lines for using as a 4-bit interface
     * @param type  Sets the panel size/addressing mode (default = LCD16x2)
     */
    TextLCD(PinName rs, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type = LCD16x2);

#if DOXYGEN_ONLY
    /** Write a character to the LCD
     *
     * @param c The character to write to the display
     */
    int putc(int c);

    /** Write a formated string to the LCD
     *
     * @param format A printf-style format string, followed by the
     *               variables to use in formating the string.
     */
    int printf(const char* format, ...);
#endif

    /** Locate to a screen column and row
     *
     * @param column  The horizontal position from the left, indexed from 0
     * @param row     The vertical position from the top, indexed from 0
     */
    void locate(int column, int row);


    /** Return the memoryaddress of screen column and row location
     *
     * @param column  The horizontal position from the left, indexed from 0
     * @param row     The vertical position from the top, indexed from 0
     * @param return  The memoryaddress of screen column and row location
     */
    int  getAddress(int column, int row);    
    
    
    /** Set the memoryaddress of screen column and row location
     *
     * @param column  The horizontal position from the left, indexed from 0
     * @param row     The vertical position from the top, indexed from 0
     */
    void setAddress(int column, int row);        

    /** Set the Cursormode
     *
     * @param show    The Cursor mode (CurOn or CurOff)
     * @param return  The current Cursor mode     
     */
    LCDCursor cursor(LCDCursor show);     

    /** Clear the screen and locate to 0,0 */
    void cls();

    /** Return the number of rows
     *
     * @param return  The number of rows
     */
    int rows();
    
    /** Return the number of columns
     *
     * @param return  The number of columns
     */  
    int columns();  

protected:
    // Stream implementation functions
    virtual int _putc(int value);
    virtual int _getc();

    int  address(int column, int row);
    void character(int column, int row, int c);
    void writeByte(int value);
    void writeCommand(int command);
    void writeData(int data);

    DigitalOut _rs, _e;
    BusOut _d;
    LCDType _type;

    int _column;
    int _row;
    LCDCursor _cursor;    
};

#endif