TextLCD.cpp

00001 
00002 #include "mbed.h"
00003 #include "TextLCD.h"
00004 
00005 #define SET_EN() (LCD_EN=1)
00006 #define SET_RS() (LCD_RS=1)
00007 #define SET_RW() (LCD_RW=1)
00008 
00009 #define CLEAR_EN() (LCD_EN=0)
00010 #define CLEAR_RS() (LCD_RS=0)
00011 #define CLEAR_RW() (LCD_RW=0)
00012 
00013 
00014 TextLCD::TextLCD(PinName rs,PinName rw, PinName e, PinName d4, PinName d5,
00015                  PinName d6, PinName d7,  const char* name) : Stream(name), LCD_RS(rs),LCD_RW(rw), LCD_EN(e),
00016     LCD_D4to7(d4,d5,d6,d7)
00017 {
00018     CLEAR_RW();
00019     wait_ms(50);  // Wait for disp to turn on
00020 
00021     CLEAR_EN(); //EN =0
00022     CLEAR_RS();
00023 
00024     init_4BitMode2LinesDisplayOn();    //enabler 4 bit mode
00025     wait_ms(1);
00026 
00027     lcdComand(0x00);
00028     wait_us(100);
00029 
00030     lcdComand(0x28);//(0b0010 1000);   // 4- bit mode   LCD 2 line 16x2 Matrix
00031     wait_us(100);
00032 
00033     lcdComand(0x01); //(0b00000001);
00034     wait_us(100);
00035     lcdComand(0x06);//(0b00000110);
00036     wait_us(100);
00037     lcdComand(0xC);//(0b0000 1100);
00038     wait_us(100);
00039 }
00040 
00041 // Causes the LCD-module to read the data on the data input pins
00042 void TextLCD::pulseEn()
00043 {
00044     SET_EN();       // EN = 1 for L-to-H /
00045     wait_us(200);
00046     CLEAR_EN();     // EN = 0 for H-to-L
00047 }
00048 
00049 //Writes the low lible of data to the LCD-module data pins D4 to D7
00050 void TextLCD::writeLcdBitD4toD7(char data)
00051 {
00052     LCD_D4to7=data;
00053 }
00054 
00055 //Enable 4 bit mode  From KS0066U Documentation
00056 void TextLCD::init_4BitMode2LinesDisplayOn()
00057 {
00058 
00059     //Start by selecting configuration mode
00060     CLEAR_RS();
00061     CLEAR_RW();
00062 
00063     wait(.015);        // Wait 150ms to ensure powered up
00064 
00065     // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus)
00066     writeLcdBitD4toD7(0x3);
00067     pulseEn();
00068     wait_ms(2);
00069     writeLcdBitD4toD7(0x3);
00070     pulseEn();
00071     wait_ms(2);
00072     writeLcdBitD4toD7(0x3);
00073     pulseEn();
00074     wait_ms(2);
00075 
00076     //Enable 4 bit mode  From KS0066U Documentation
00077     writeLcdBitD4toD7(0x2);// (0b0010)  4- bit start / 4-bit mode
00078     wait_us(100);
00079     writeLcdBitD4toD7(0x2);
00080     pulseEn();
00081     wait_us(100);
00082     writeLcdBitD4toD7(0x2);////(0b0010);   // Select 4- bit start  (Already on the out port no need to write once more )
00083     pulseEn();  //LCD exec function
00084     wait_us(50);
00085 
00086     writeLcdBitD4toD7(0xC);//(0b1100);   // 2 Lines + Disp On
00087     pulseEn();  //LCD exec function
00088 
00089     lcdComand(0x01);  // Clear Display
00090     wait_ms(3);
00091     lcdComand(0x28);  // Function set 001 BW N F - -    
00092     lcdComand(0x06);  // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes    
00093     lcdComand(0x0C);  // Dispon + Hide cursor
00094     wait_us(100);
00095 }
00096 
00097 
00098 //Writes the byte comand to the LCD-module using 4 bits mode
00099 void TextLCD::lcdComand(unsigned char cmd)
00100 {
00101     writeLcdBitD4toD7(cmd>>4); //Write the first high cmd nibble
00102 
00103     CLEAR_RS();     // RS = 0 for command
00104     CLEAR_RW();     // RW = 0 for write
00105 
00106     pulseEn();  //EN Hi-Lo
00107 
00108     writeLcdBitD4toD7(cmd); //Write the second low cmd nibble
00109 
00110     pulseEn();  //EN H to Lo
00111 
00112     wait_us(100); //wait
00113 }
00114 
00115 void TextLCD::lcdData(unsigned char data)
00116 {
00117     writeLcdBitD4toD7(data>>4); //Write the first high data nibble
00118 
00119     SET_RS();       // RS = 1 for data
00120     CLEAR_RW();     // RW = 0 for write
00121     pulseEn();      // EN H to Lo
00122     wait_us(100); //wait
00123 
00124     writeLcdBitD4toD7(data);
00125 
00126     pulseEn();  //EN H to Lo
00127     wait_us(100); //wait
00128 }
00129 
00130 //Moves cursor to the X,Y position
00131 void TextLCD::gotoxy(int x, int y)
00132 {
00133     unsigned char firstCharAdr[]= { 0x80,0xc0,0x94,0xD4};
00134     lcdComand(firstCharAdr[y-1]+ x -1);
00135 
00136     wait_us(100);
00137 }
00138 
00139 int TextLCD::_putc(int value)
00140 {
00141     lcdData(value);
00142     return value;
00143 }
00144 
00145 int TextLCD::_getc()
00146 {
00147     return -1;
00148 }