I2CTextLCD.h

00001 /* mbed I2CTextLCD Library
00002  * Copyright (c) 2007-2009 sford
00003  * Copyright (c) 2010 Wim De Roeve  changed to work with I2C PCF8575
00004  * Released under the MIT License: http://mbed.org/license/mit
00005  */
00006 
00007 #ifndef MBED_I2CTextLCD_H
00008 #define MBED_I2CTextLCD_H
00009 
00010 #include "mbed.h"
00011 #include "Stream.h"
00012 
00013 #define RS_ON         0x01   //PCF port P0
00014 #define E1_ON         0x02   //PCF port P1 
00015 #define E2_ON         0x40   //P6
00016 #define BACKLIGHT_ON  0x80   //P7
00017 
00018 /* Display ON/OFF Control defines */
00019 #define DON                0x0F  //0b00001111  Display on 
00020 #define DOFF               0x0B  //0b00001011  Display off 
00021 #define CURSOR_ON          0x0F  //0b00001111  Cursor on 
00022 #define CURSOR_OFF         0x0D  //0b00001101  Cursor off 
00023 #define BLINK_ON           0x0F  //0b00001111  Cursor Blink 
00024 #define BLINK_OFF          0x0E  //0b00001110  Cursor No Blink 
00025 
00026 /* Cursor or Display Shift defines */
00027 #define SHIFT_CUR_LEFT     0x13  //0b00010011  Cursor shifts to the left 
00028 #define SHIFT_CUR_RIGHT    0x17  //0b00010111  Cursor shifts to the right 
00029 #define SHIFT_DISP_LEFT    0x1B  //0b00011011  Display shifts to the left 
00030 #define SHIFT_DISP_RIGHT   0x1F  //0b00011111  Display shifts to the right 
00031 
00032 /* Function Set defines */
00033 #define EIGHT_BITMODE      0x03  //0b00000011  8-bit Interface D4-D7
00034 #define FOUR_BITMODE       0x02  //0b00000010  4-bit Interface D4-D7
00035 #define LINE_5X7           0x30  //0b00110000
00036 #define LINE_5X10          0x34  //0b00110100
00037 #define LINES_5X7          0x38  //0b00111000
00038 
00039 // Addtional define to support display mode
00040 
00041 #define DISP_FLIP_NONE     0x00  //0b00111100  No flip
00042 #define CLEAR_LCD          0x01  //0b00000001 
00043 
00044 // Addtional define to support entry mode & shift mode
00045 //#define ENTRY_CURSOR_DEC 0b00000101 /* Entry cursor move left */
00046 //#define ENTRY_CURSOR_INC 0b00000111 /* Entry cursor move to right */
00047 //#define ENTRY_DISPLAY_SHIFT 0b00000111 /* Entry the display to shift */
00048 //#define ENTRY_DISPLAY_NO_SHIFT 0b00000110 /* Entry no shift */
00049 
00050 // Use generic address
00051 
00052 #define LINE0 0x80
00053 #define LINE1 0xC0 
00054 #define LINE2 0x94 
00055 #define LINE3 0xD4 
00056 namespace mbed {
00057 
00058 /* Class: I2CTextLCD
00059  * A 16x2 Text LCD controller
00060  *
00061  * Allows you to print to a Text LCD screen, and locate/cls. Could be
00062  * turned in to a more generic libray.
00063  *
00064  * If you are connecting multiple displays, you can connect them all in
00065  * parallel, the address of the PCF8575 or PCF8574 must be unique for each
00066  * display.
00067  *
00068  * Example:
00069  * > #include "mbed.h"
00070  * > #include "I2CTextLCD.h"
00071  * >
00072  * > I2CTextLCD lcd(p9, P10, 0x40); // sda scl, address
00073  * >
00074  * > int main() {
00075  * >     lcd.printf("Hello World!");
00076  * > }
00077  */
00078 class I2CTextLCD : public Stream {
00079 
00080 public:
00081     /* Constructor: I2CTextLCD
00082      * Create a I2CTextLCD object
00083      *
00084      * wiring
00085      *
00086      * PCF8575/PCF8574  to  LCD..........Rods Fassung:
00087      * ----------------------
00088      * P0              -  D4.............RS
00089      * P1              -  D5..............E
00090      * P2              -  D6.............D4
00091      * P3              -  D7.............D5
00092      * P4              -  RS.............D6
00093      * P5              -  E1.............D7
00094      * P6              -  E2
00095      * P7              -  backlight (connected to a relay)
00096      * gnd             -  R/W
00097      *
00098      */
00099 // I2C address for PCF8574AN [TI] is 0x38 for A0..2 = 000 0x39 for 001, NO it is 0x70.
00100 // I2C slave addres for NXP PCF8574 = 0x 40 for A0..2 = 000 0x42 for 001
00101 // I2C slave addres for NXP PCF8574A = 0x 70 for A0..2 = 000 0x72 for 001
00102 
00103     I2CTextLCD(PinName sda, PinName scl, int address, int columns = 20, int rows = 4, bool backlight = false);
00104 
00105 #if 0 // Inhereted from Stream, for documentation only
00106     /* Function: putc
00107      *  Write a character
00108      *
00109      * Variables:
00110      *  c - The character to write to the serial port
00111      */
00112     int putc(int c);
00113 
00114     /* Function: printf
00115      *  Write a formated string
00116      *
00117      * Variables:
00118      *  format - A printf-style format string, followed by the
00119      *      variables to use in formating the string.
00120      */
00121     int printf(const char* format, ...);
00122 #endif
00123 
00124     /* Function: locate
00125      * Locate to a certian position
00126      *
00127      * Variables:
00128      *  column - the column to locate to, from 0..15
00129      *  row - the row to locate to, from 0..1
00130      */
00131     virtual void locate(int column, int row);
00132 
00133     /* Function: cls
00134      * Clear the screen, and locate to 0,0
00135      */
00136     virtual void cls();
00137 
00138     virtual void reset();
00139 
00140     /* Function: backlight
00141     * Sets the backlight on or off
00142     *
00143     * Variables:
00144     *  on (true or false)
00145     */
00146     //virtual void backlight(bool on);
00147 
00148 protected:
00149 
00150     void clock();
00151     void init8574A(void);
00152     void writeData(int data);
00153     void writeCommand(int command);
00154     void writeByte(int value, bool rs);
00155     //void writeNibble(int value, bool rs);
00156     // void writeI2CByte(int data);
00157     int readI2C();
00158     virtual int _putc(int c);
00159     virtual int _getc();
00160     virtual void newline();
00161 
00162     int _row;
00163     int _column;
00164     int _columns;
00165     int _rows;
00166 
00167     I2C _i2c;
00168     int _i2cAddress;
00169     bool _backlight;
00170 
00171 
00172 private:
00173 
00174 
00175 
00176 };
00177 
00178 }
00179 
00180 #endif
00181