PIC'ler için I2C LCD sürücüsü

  
 //----------------------------------------------------------------------------- 
 // Title:         i2c_Flex_LCD 
 // Description:   Driver for common LCD with 1/2/3 or 4 rows by 1...20 columns 
 //                using PCF8574T interface board with I2C protocol. 
 // Date:          Nov-2013 
 // Ver.Rev.:      1.1 
 // Author:        Hugo Silva (sergio-hugo@bol.com.br) #Based on the routines of 
 //                "20X4_LCD_I2C_DRIVER.h" from Pumrin S. and "lcd4_i2c.c" from XP8100 
 //----------------------------------------------------------------------------- 
 // 
 // lcd_init() Must be called before any other function. 
 // 
 // lcd_putc(c) Will display c on the next position of the LCD. 
 //  
 //     \f Clear LCD display 
 //      
 //     \n Set write position on next lcd line 
 //     \b LCD backspace 
 //     lcd_gotoxy(x,y) Set write position on LCD (upper left is 1,1) 
 // 
 // lcd_backlight_led(ON)/lcd_backlight_led(OFF) = Turn ON/OFF LCD Backlight LED 
 // 
 //----------------------------------------------------------------------------- 
 // LCD pins D0-D3 are not used. 
 //----------------------------------------------------------------------------- 
 // 
 // Comment   : Control of a compatible LCD (1...4 rows by 1...4 columns) from 
 //              a bus I2C with an EXPANDER of I/O with connection I2C. 
 //              The tests of these routines have been programmed using the IC 
 //              Phillips PCF8574T. I've used 4 bits mode programming. 
 //              The 8 bits mode programming is possible if you use 2 x PCF8574T. 
 //              RW Pin is not being used. 
 // 
 // As defined in the following structure the pin connection is as follows: 
 // 
 //  PCF8574P     LCD 
 //  ========     ====== 
 //     P0        RS 
 //     P1        RW    (Not used!) 
 //     P2        Enable  
 //     P3        Led Backlight 
 //     P4        D4 
 //     P5        D5 
 //     P6        D6 
 //     P7        D7 
 // 
 //  The SCL and SDA pins should be pull-up resistor as shown below: 
 // 
 //             +5v 
 //               | 
 //               < 
 //               > 4.7K        
 //               <          
 //To PIC         |          To i2c slave 
 //pin xx ------------------ SDA pin  
 //(SDA)                      
 //              +5v 
 //               | 
 //               < 
 //               > 4.7K        
 //               <          
 //To PIC         |          To i2c slave 
 //pin xx ------------------ SCL pin  
 //(SCL) 
 // 
 //To PIC                    To i2c slave 
 //Vss pin ----------------- Vss or ground pin  
 //                | 
 //              ----- 
 //               ---  Ground 
 //                -  
 //  
 // THIS DOCUMENT IS PROVIDED TO THE USER "AS IS" 
 //----------------------------------------------------------------------------- 
 #ifndef LCD_ADDR 
 #define LCD_ADDR              0x4E        //I2C slave address for LCD module 
 #endif 
 #ifndef lcd_total_rows 
 #define lcd_total_rows        4           //Number of rows: 1,2,3 or 4 
 #endif 
 #ifndef lcd_total_columns 
 #define lcd_total_columns     20          //Number of columns: 1...20 
 #endif    
  
 #define RS                    0b00000001  //P0 - PCF8574T Pin connected to RS 
 #define RW                    0b00000010  //P1 - PCF8574T Pin connected to RW 
 #define ENABLE                0b00000100  //P2 - PCF8574T Pin connected to EN 
 #define LCD_BACKLIGHT         0b00001000  //P3 - PCF8574T Pin connected to BACKLIGHT LED 
  
 #define addr_row_one          0x00        //LCD RAM address for row 1 
 #define addr_row_two          0x40        //LCD RAM address for row 2 
 #define addr_row_three        0x14        //LCD RAM address for row 3 
 #define addr_row_four         0x54        //LCD RAM address for row 4 
  
 #define ON                    1 
 #define OFF                   0 
 #define NOT                   ~ 
 #define data_shifted          data<<4 
 int8 new_row_request=1, BACKLIGHT_LED=LCD_BACKLIGHT; 
  
 void lcd_backlight_led(byte bl) 
 {  
       If (bl) BACKLIGHT_LED=LCD_BACKLIGHT; else BACKLIGHT_LED=OFF; 
 } 
  
 void i2c_send_nibble(byte data, byte type) 
 {    
    switch (type) 
    {      
       case 0 :      
       i2c_write(data_shifted | BACKLIGHT_LED); 
       delay_cycles(1); 
       i2c_write(data_shifted | ENABLE | BACKLIGHT_LED ); 
       delay_us(2); 
       i2c_write(data_shifted & NOT ENABLE | BACKLIGHT_LED); 
       break; 
       
       case 1 : 
       i2c_write(data_shifted | RS | BACKLIGHT_LED); 
       delay_cycles(1); 
       i2c_write(data_shifted | RS | ENABLE | BACKLIGHT_LED ); 
       delay_us(2); 
      i2c_write(data_shifted | RS | BACKLIGHT_LED); //fix 
       break; 
    } 
 }  
     
 void lcd_send_byte(byte data, byte type) 
    { 
         i2c_start(); 
         i2c_write(LCD_ADDR); 
         i2c_send_nibble(data >> 4 , type); 
         i2c_send_nibble(data & 0xf , type); 
         i2c_stop();        
    } 
  
 void lcd_clear() 
 {  
         lcd_send_byte(0x01,0); 
         delay_ms(2); 
         new_row_request=1; 
 } 
  
 void lcd_init(void) 
 { 
    byte i; 
    byte CONST lcd_type=2;  // 0=5x7, 1=5x10, 2=2 lines 
    byte CONST LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6}; // These bytes need to be sent to the LCD to start it up. 
  
    disable_interrupts(GLOBAL); 
    delay_ms(50); //LCD power up delay 
     
    i2c_start(); 
    i2c_write(LCD_ADDR); 
       i2c_send_nibble(0x00,0); 
       delay_ms(15); 
     
    for (i=1;i<=3;++i)    
    { 
       i2c_send_nibble(0x03,0); 
       delay_ms(5); 
    }    
       i2c_send_nibble(0x02,0); 
       delay_ms(5); 
    i2c_stop(); 
     
    for (i=0;i<=3;++i) { 
    lcd_send_byte(LCD_INIT_STRING[i],0); 
    delay_ms(5); 
    } 
    lcd_clear();  //Clear Display 
    enable_interrupts(GLOBAL); 
 } 
  
 void lcd_gotoxy( byte x, byte y) 
 { 
 byte row,column,row_addr,lcd_address; 
 static char data; 
  
    if (y>lcd_total_rows) row=lcd_total_rows; else row=y; 
   
    switch(row) 
    { 
       case 1:  row_addr=addr_row_one;     break; 
       case 2:  row_addr=addr_row_two;     break; 
       case 3:  row_addr=addr_row_three;   break; 
       case 4:  row_addr=addr_row_four;    break; 
       default: row_addr=addr_row_one;     break;  
    }  
     
    if (x>lcd_total_columns) column=lcd_total_columns; else column=x;  
    lcd_address=(row_addr+(column-1)); 
    lcd_send_byte(0x80|lcd_address,0); 
 } 
  
 //Display the character on LCD screen. 
 void LCD_PUTC(char in_data) 
 {    
   switch(in_data) 
    {  
      case '\f': lcd_clear();                       break;                
       
      case ' 
 ': 
      new_row_request++; 
      if (new_row_request>lcd_total_rows) new_row_request=1; 
      lcd_gotoxy(1, new_row_request); 
      break; 
                   
      case '\b': lcd_send_byte(0x10,0);             break; 
         
      default: lcd_send_byte(in_data,1);            break;      
       
    } 
 }  
 

#define LCD_ADDR              0x4E        //LCD modülünün I2C adresi(Write adresi olacak. Varsayılan değer 0x4E) 
 #define lcd_total_rows        2          //LCD satır sayısı(varsayılan 4) 
 #define lcd_total_columns     16          //LCD sütun sayısı (varsayılan 20) 
 #include <i2c_lcd.c>         //LCD sürücüsüne verdiğiniz ad