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