TextLCD.h

00001 /* mbed TextLCD Library
00002  * Copyright (c) 2007-2009 sford
00003  * Released under the MIT License: http://mbed.org/license/mit
00004  *
00005  * TODO: Needs serious rework/neatening up!
00006  */
00007  
00008 #ifndef MBED_TEXTLCD_H
00009 #define MBED_TEXTLCD_H
00010 
00011 #include "Stream.h"
00012 #include "DigitalOut.h"
00013 #include "BusOut.h"
00014 
00015 namespace mbed {
00016 
00017 /* Class: TextLCD
00018  * A 16x2 Text LCD controller
00019  *
00020  * Allows you to print to a Text LCD screen, and locate/cls. Could be
00021  * turned in to a more generic libray.
00022  *
00023  * If you are connecting multiple displays, you can connect them all in
00024  * parallel except for the enable (e) pin, which must be unique for each
00025  * display.
00026  *
00027  * Example:
00028  * > #include "mbed.h"
00029  * > #include "TextLCD.h"
00030  * >
00031  * > TextLCD lcd(p24, p25, p26, p27, p28, p29, p30); // rs, rw, e, d0, d1, d2, d3
00032  * >
00033  * > int main() {
00034  * >     lcd.printf("Hello World!");
00035  * > }
00036  */
00037 class TextLCD : public Stream {
00038 
00039 public:
00040     /* Constructor: TextLCD
00041      * Create a TextLCD object, connected to the specified pins
00042      *
00043      * All signals must be connected to DigitalIn compatible pins. 
00044      *
00045      * Variables:
00046      *  rs -  Used to specify data or command
00047      *  rw - Used to determine read or write
00048      *  e - enable
00049      *  d0..d3 - The data lines
00050      */
00051     TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, 
00052         PinName d2, PinName d3, int columns = 16, int rows = 2);
00053 
00054 #if 0 // Inhereted from Stream, for documentation only
00055     /* Function: putc
00056      *  Write a character
00057      *
00058      * Variables:
00059      *  c - The character to write to the serial port
00060      */
00061     int putc(int c);
00062 
00063     /* Function: printf
00064      *  Write a formated string
00065      *
00066      * Variables:
00067      *  format - A printf-style format string, followed by the
00068      *      variables to use in formating the string.
00069      */
00070     int printf(const char* format, ...);
00071 #endif
00072         
00073     /* Function: locate
00074      * Locate to a certian position
00075      *
00076      * Variables:
00077      *  column - the column to locate to, from 0..15
00078      *  row - the row to locate to, from 0..1
00079      */
00080     virtual void locate(int column, int row);
00081     
00082     /* Function: cls
00083      * Clear the screen, and locate to 0,0
00084      */
00085     virtual void cls();    
00086     
00087     virtual void reset();
00088         
00089 //protected:
00090 
00091     void clock();
00092     void writeData(int data);
00093     void writeCommand(int command);
00094     void writeByte(int value);
00095     void writeNibble(int value);
00096     virtual int _putc(int c);        
00097     virtual int _getc();
00098     virtual void newline();                
00099             
00100     int _row;
00101     int _column;    
00102     DigitalOut _rw, _rs, _e;
00103     BusOut _d;
00104     int _columns;
00105     int _rows;
00106 
00107 };
00108 
00109 }
00110 
00111 #endif