TextLCD_20X4.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 /*
00009  *  2010/05/14 modified for 20X4 LCD by ym1784
00010  */
00011 
00012 #ifndef MBED_TEXTLCD_20X4_H
00013 #define MBED_TEXTLCD_20X4_H
00014 
00015 #include "Stream.h"
00016 #include "DigitalOut.h"
00017 #include "BusOut.h"
00018 
00019 namespace mbed {
00020 
00021 /* Class: TextLCD_20X4
00022  * A 20x4 Text LCD controller ... ym1784
00023  *
00024  * Allows you to print to a Text LCD screen, and locate/cls. Could be
00025  * turned in to a more generic libray.
00026  *
00027  * If you are connecting multiple displays, you can connect them all in
00028  * parallel except for the enable (e) pin, which must be unique for each
00029  * display.
00030  *
00031  * Example:
00032  * > #include "mbed.h"
00033  * > #include "TextLCD_20X4.h"
00034  * >
00035  * > TextLCD_20X4 lcd(p21, p22, p23, p24, p25, p26); // rs, e, d0, d1, d2, d3
00036  * >
00037  * > int main() {
00038  * >     lcd.printf("Hello World!");
00039  * > }
00040  */
00041 class TextLCD_20X4 : public Stream {
00042 
00043 public:
00044     /* Constructor: TextLCD_20X4
00045      * Create a TextLCD_20X4 object, connected to the specified pins
00046      *
00047      * All signals must be connected to DigitalIn compatible pins.
00048      *
00049      * Variables:
00050      *  rs -  Used to specify data or command
00051      *  e - enable
00052      *  d0..d3 - The data lines
00053      */
00054     TextLCD_20X4(PinName rs, PinName e, PinName d0, PinName d1,
00055         PinName d2, PinName d3, int columns = 20, int rows = 4);
00056 
00057 #if 0 // Inhereted from Stream, for documentation only
00058     /* Function: putc
00059      *  Write a character
00060      *
00061      * Variables:
00062      *  c - The character to write to the serial port
00063      */
00064     int putc(int c);
00065 
00066     /* Function: printf
00067      *  Write a formated string
00068      *
00069      * Variables:
00070      *  format - A printf-style format string, followed by the
00071      *      variables to use in formating the string.
00072      */
00073     int printf(const char* format, ...);
00074 #endif
00075 
00076     /* Function: locate
00077      * Locate to a certian position
00078      *
00079      * Variables:
00080      *  column - the column to locate to, from 0..19
00081      *  row - the row to locate to, from 0..3
00082      */
00083     virtual void locate(int column, int row);
00084 
00085     /* Function: cls
00086      * Clear the screen
00087      */
00088     virtual void cls();
00089 
00090     virtual void reset();
00091 
00092 //protected:
00093 
00094     void clock();
00095     void writeData(int data);
00096     void writeCommand(int command);
00097     void writeByte(int value);
00098     void writeNibble(int value);
00099     virtual int _putc(int c);
00100     virtual int _getc();
00101     virtual void newline();
00102 
00103     int _row;
00104     int _column;
00105     DigitalOut _rs, _e;
00106     BusOut _d;
00107     int _columns;
00108     int _rows;
00109     int address;
00110 };
00111 
00112 }
00113 
00114 #endif