TextLCD.h

00001 /* mbed TextLCD Library, for a 4-bit LCD based on HD44780
00002  * Copyright (c) 2007-2010, sford, http://mbed.org
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020  * THE SOFTWARE.
00021  */
00022 
00023 #ifndef MBED_TEXTLCD_H
00024 #define MBED_TEXTLCD_H
00025 
00026 #include "mbed.h"
00027 
00028 /** A TextLCD interface for driving 4-bit HD44780-based LCDs
00029  *
00030  * Currently supports 16x2, 20x2 and 20x4 panels
00031  *
00032  * @code
00033  * #include "mbed.h"
00034  * #include "TextLCD.h"
00035  * 
00036  * TextLCD lcd(p10, p12, p15, p16, p29, p30); // rs, e, d4-d7
00037  * 
00038  * int main() {
00039  *     lcd.printf("Hello World!\n");
00040  * }
00041  * @endcode
00042  */
00043 class TextLCD : public Stream {
00044 public:
00045 
00046     /** LCD panel format */
00047     enum LCDType {
00048         LCD16x2     /**< 16x2 LCD panel (default) */
00049         , LCD16x2B  /**< 16x2 LCD panel alternate addressing */
00050         , LCD20x2   /**< 20x2 LCD panel */
00051         , LCD20x4   /**< 20x4 LCD panel */
00052     };
00053 
00054     /** Create a TextLCD interface
00055      *
00056      * @param rs    Instruction/data control line
00057      * @param e     Enable line (clock)
00058      * @param d4-d7 Data lines for using as a 4-bit interface
00059      * @param type  Sets the panel size/addressing mode (default = LCD16x2)
00060      */
00061     TextLCD(PinName rs, PinName rw, PinName e, PinName d4, PinName d5, PinName d6, PinName d7, LCDType type = LCD16x2);
00062 
00063 #if DOXYGEN_ONLY
00064     /** Write a character to the LCD
00065      *
00066      * @param c The character to write to the display
00067      */
00068     int putc(int c);
00069 
00070     /** Write a formated string to the LCD
00071      *
00072      * @param format A printf-style format string, followed by the
00073      *               variables to use in formating the string.
00074      */
00075     int printf(const char* format, ...);
00076 #endif
00077 
00078     /** Locate to a screen column and row
00079      *
00080      * @param column  The horizontal position from the left, indexed from 0
00081      * @param row     The vertical position from the top, indexed from 0
00082      */
00083     void locate(int column, int row);
00084 
00085     /** Clear the screen and locate to 0,0 */
00086     void cls();
00087 
00088     int rows();
00089     int columns();
00090 
00091 protected:
00092 
00093     // Stream implementation functions
00094     virtual int _putc(int value);
00095     virtual int _getc();
00096 
00097     int address(int column, int row);
00098     void character(int column, int row, int c);
00099     void writeByte(int value);
00100     void writeCommand(int command);
00101     void writeData(int data);
00102     void writeNibble(int data);
00103     void clock(void);
00104     
00105     DigitalOut _rs, _rw, _e;
00106     BusOut _d;
00107     LCDType _type;
00108 
00109     int _column;
00110     int _row;
00111 };
00112 
00113 #endif