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:
2013-02-10
Revision:
14:0c32b66b14b8
Parent:
13:24506ba22480
Child:
15:b70ebfffb258

File content as of revision 14:0c32b66b14b8:

/* mbed TextLCD Library, for a 4-bit LCD based on HD44780
 * Copyright (c) 2007-2010, sford, http://mbed.org
 *               2013, v01: WH, Added LCD types, fixed LCD address issues, added Cursor and UDCs 
 *               2013, v02: WH, Added I2C and SPI bus interfaces 
 *
 * 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(p15, p16, p17, p18, p19, p20); // RS, E, D4-D7 
 * 
 * int main() {
 *     lcd.printf("Hello World!\n");
 * }
 * @endcode
 */


//Pin Defines for I2C PCF8574 and SPI 74595 Bus
//LCD and serial portexpanders should be wired accordingly 
//Note: LCD RW pin must be connected to GND
//      E2 may be used for future expansion to LCD40x4
//      BL may be used for future expansion to control backlight
//
#define D_LCD_PIN_D4   0x00
#define D_LCD_PIN_D5   0x01
#define D_LCD_PIN_D6   0x02
#define D_LCD_PIN_D7   0x03
#define D_LCD_PIN_RS   0x04
#define D_LCD_PIN_E    0x05
#define D_LCD_PIN_E2   0x06
#define D_LCD_PIN_BL   0x07

#define D_LCD_BUS_MSK  0x0F

//Bitpattern Defines for I2C PCF8574 and SPI 74595 Bus
//
#define D_LCD_D4       (1<<D_LCD_PIN_D4)
#define D_LCD_D5       (1<<D_LCD_PIN_D5)
#define D_LCD_D6       (1<<D_LCD_PIN_D6)
#define D_LCD_D7       (1<<D_LCD_PIN_D7)
#define D_LCD_RS       (1<<D_LCD_PIN_RS)
#define D_LCD_E        (1<<D_LCD_PIN_E)
#define D_LCD_E2       (1<<D_LCD_PIN_E2)
#define D_LCD_BL       (1<<D_LCD_PIN_BL)



/** Some sample User Defined Chars 5x7 dots */
const char udc_ae[] = {0x00, 0x00, 0x1B, 0x05, 0x1F, 0x14, 0x1F, 0x00};  //æ
const char udc_0e[] = {0x00, 0x00, 0x0E, 0x13, 0x15, 0x19, 0x0E, 0x00};  //ø
const char udc_ao[] = {0x0E, 0x0A, 0x0E, 0x01, 0x0F, 0x11, 0x0F, 0x00};  //å
const char udc_AE[] = {0x0F, 0x14, 0x14, 0x1F, 0x14, 0x14, 0x17, 0x00};  //Æ
const char udc_0E[] = {0x0E, 0x13, 0x15, 0x15, 0x15, 0x19, 0x0E, 0x00};  //Ø
const char udc_AA[] = {0x0E, 0x0A, 0x0E, 0x11, 0x1F, 0x11, 0x11, 0x00};  //Å

const char udc_0[]  = {0x18, 0x14, 0x12, 0x11, 0x12, 0x14, 0x18, 0x00};  // |>
const char udc_1[]  = {0x03, 0x05, 0x09, 0x11, 0x09, 0x05, 0x03, 0x00};  // <|
const char udc_2[]  = {0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00};  // |
const char udc_3[]  = {0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x00};  // ||
const char udc_4[]  = {0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x00};  // |||
const char udc_5[]  = {0x00, 0x1f, 0x00, 0x1f, 0x00, 0x1f, 0x00, 0x00};  // =
const char udc_6[]  = {0x15, 0x0a, 0x15, 0x0a, 0x15, 0x0a, 0x15, 0x00};  // checkerboard
const char udc_7[]  = {0x10, 0x08, 0x04, 0x02, 0x01, 0x00, 0x10, 0x00};  // \

const char udc_degr[]   = {0x06, 0x09, 0x09, 0x06, 0x00, 0x00, 0x00, 0x00};  // Degree symbol

const char udc_TM_T[]   = {0x1F, 0x04, 0x04, 0x04, 0x00, 0x00, 0x00, 0x00};  // Trademark T
const char udc_TM_M[]   = {0x11, 0x1B, 0x15, 0x11, 0x00, 0x00, 0x00, 0x00};  // Trademark M

//const char udc_Bat_Hi[] = {0x0E, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Full
//const char udc_Bat_Ha[] = {0x0E, 0x11, 0x13, 0x17, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Half
//const char udc_Bat_Lo[] = {0x0E, 0x11, 0x11, 0x11, 0x11, 0x11, 0x1F, 0x00};  // Battery Low
const char udc_Bat_Hi[] = {0x0E, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Full
const char udc_Bat_Ha[] = {0x0E, 0x11, 0x11, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Battery Half
const char udc_Bat_Lo[] = {0x0E, 0x11, 0x11, 0x11, 0x11, 0x1F, 0x1F, 0x00};  // Battery Low

const char udc_bar_1[]  = {0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00};  // Bar 1
const char udc_bar_2[]  = {0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x00};  // Bar 11
const char udc_bar_3[]  = {0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x1C, 0x00};  // Bar 111
const char udc_bar_4[]  = {0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x00};  // Bar 1111
const char udc_bar_5[]  = {0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x00};  // Bar 11111


/** A TextLCD interface for driving 4-bit HD44780-based LCDs
 *
 * Currently supports 8x1, 8x2, 16x1, 16x2, 16x4, 20x2, 20x4, 24x2, 24x4 and 40x2 panels
 *
 */
class TextLCD : public Stream {
public:

    /** LCD panel format */
    enum LCDType {
        LCD8x1,     /**<  8x1 LCD panel */    
        LCD8x2,     /**<  8x2 LCD panel */          
        LCD16x1,    /**< 16x1 LCD panel (actually 8x2) */          
        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 {
        CurOff_BlkOff,  /**<  Cursor Off, Blinking Char Off */    
        CurOn_BlkOff,   /**<  Cursor On, Blinking Char Off */    
        CurOff_BlkOn,   /**<  Cursor Off, Blinking Char On */    
        CurOn_BlkOn,    /**<  Cursor On, Blinking Char On */    
    };


    /** Create a TextLCD interface for using regural mbed pins
     *
     * @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);
    
    /** Create a TextLCD interface using an I2C PC8574 portexpander
     *
     * @param i2c             I2C Bus
     * @param deviceAddress   I2C slave address (PCF8574)
     * @param type            Sets the panel size/addressing mode (default = LCD16x2)
     */
    TextLCD(I2C *i2c, char deviceAddress, LCDType type = LCD16x2);


    /** Create a TextLCD interface using an SPI 74595 portexpander
     *
     * @param spi             SPI Bus
     * @param cs              chip select pin (active low)
     * @param type            Sets the panel size/addressing mode (default = LCD16x2)
     */
    TextLCD(SPI *spi, PinName cs, 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);        


    /** 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();  

    /** Set the Cursormode
     *
     * @param show    The Cursor mode (CurOff_BlkOff, CurOn_BlkOff, CurOff_BlkOn, CurOn_BlkOn)
     */
    void setCursor(LCDCursor show);     


    /** Set User Defined Characters
     *
     * @param unsigned char c   The Index of the UDC (0..7)
     * @param char *udc_data    The bitpatterns for the UDC (8 bytes of 5 significant bits)     
     */
    void setUDC(unsigned char c, char *udc_data);

protected:
   /* LCD Bus control */
    enum _LCDBus {
        _PinBus,  /*<  Regular mbed pins */    
        _I2CBus,  /*<  I2C PCF8574 Portexpander */    
        _SPIBus   /*<  SPI 74595 */    
    };

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

    void _init();    
    int  _address(int column, int row);
    void _character(int column, int row, int c);
    
//Low level writes to LCD Bus (serial or parallel)
    void _setEnable(bool value);
    void _setRS(bool value);  
    void _setData(int value);
    void _setCS(bool value);
    
//Low level writes to LCD serial bus only
    void _writeBus();      

//Low level writes to LCD
    void _writeByte(int value);
    void _writeCommand(int command);
    void _writeData(int data);
  
// Regular mbed pins bus
    DigitalOut _rs, _e;
    BusOut _d;
    
// I2C bus    
    I2C *_i2c;
    unsigned char _slaveAddress;
    
// SPI bus        
    SPI *_spi;
    DigitalOut _cs;    
    
//Bus Interface type    
    _LCDBus _busType;

// Internal bus mirror value for serial only
    char _lcd_bus;   
    
//Display type
    LCDType _type;

// Cursor
    int _column;
    int _row;
    LCDCursor _cursor;    
};

#endif