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// ************************************************ // *** 采用4位数据线的1602液晶驱动程序 *** // *** LCD.C *** // ************************************************ #define ENABLE_BIT_DEFINITIONS #define LCD_C #include "includes.h" // ***** Define I/O pins ***** // #define BIT7 0x80 #define BIT6 0x40 #define BIT5 0x20 #define BIT4 0x10 #define BIT3 0x08 #define BIT2 0x04 #define BIT1 0x02 #define BIT0 0x01 // *** Set port for LCD Data Bus 8 bit mode *** // #define LCD_OP_PORT PORTB #define LCD_IP_PORT PINB #define LCD_DIR_PORT DDRB // *** Set LCD Enable Port and Bit values *** // //#define LCD_EN LCD_OP_PORT.2 // *** Set LCD Register Select Port and Bit values *** // //#define LCD_RS LCD_OP_PORT.0 // *** Set LCD Read/Write Port and Bit values *** // //#define LCD_RW LCD_OP_PORT.1 /****************************************************************/ #define LCD_EN (1 << 2) //引脚定义 #define LCD_RS (1 << 0) #define LCD_RW (1 << 1) #define lcd_set_e() (LCD_OP_PORT |= LCD_EN) //置位与清零 #define lcd_set_rs() (LCD_OP_PORT |= LCD_RS) #define lcd_set_rw() (LCD_OP_PORT |= LCD_RW) #define lcd_clear_e() (LCD_OP_PORT &= ~LCD_EN) #define lcd_clear_rs() (LCD_OP_PORT &= ~LCD_RS) #define lcd_clear_rw() (LCD_OP_PORT &= ~LCD_RW) /****************************************************************/ #define LCD_ON 0x0C #define LCD_CURS_ON 0x0D #define LCD_OFF 0x08 #define LCD_HOME 0x02 #define LCD_CLEAR 0x01 #define LCD_NEW_LINE 0xC0 #define LCD_FUNCTION_SET 0x28 #define LCD_MODE_SET 0x06 void LCD_INIT(void) { LCD_DIR_PORT = 0xff; // LCD port output LCD_OP_PORT = 0x30; // Load high-data to port lcd_clear_rw(); // Set LCD to write lcd_clear_rs(); // Set LCD to command lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD delay_nus(40); lcd_clear_rw() ; // Set LCD to write lcd_clear_rs(); // Set LCD to command lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD delay_nus(40); lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD delay_nus(40); LCD_OP_PORT = 0x20; lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD delay_nus(40); } //*****************************************************// // This routine will return the busy flag from the LCD // //*****************************************************// void LCD_Busy ( void ) { unsigned char temp,high; unsigned char low; LCD_DIR_PORT = 0x0f; // Make I/O Port input do { temp=LCD_OP_PORT; temp=temp&BIT3; LCD_OP_PORT=temp; lcd_set_rw(); // Set LCD to READ lcd_clear_rs(); lcd_set_e(); delay_nus(3); high = LCD_IP_PORT; // read the high nibble. lcd_clear_e(); // Disable LCD lcd_set_e(); asm("nop"); asm("nop"); low = LCD_IP_PORT; // read the low nibble. lcd_clear_e(); // Disable LCD } while(high & 0x80); delay_nus(20); } // ********************************************** // // *** Write a control instruction to the LCD *** // // ********************************************** // void LCD_WriteControl (unsigned char CMD) { char temp; LCD_Busy(); // Test if LCD busy LCD_DIR_PORT = 0xff; // LCD port output temp=LCD_OP_PORT; temp=temp&BIT3; LCD_OP_PORT =(CMD & 0xf0)|temp; // Load high-data to port lcd_clear_rw(); // Set LCD to write lcd_clear_rs(); // Set LCD to command lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD LCD_OP_PORT =(CMD<<4)|temp; // Load low-data to port lcd_clear_rw(); // Set LCD to write lcd_clear_rs(); // Set LCD to command lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD } // ***************************************** // // *** Write one byte of data to the LCD *** // // ***************************************** // void LCD_WriteData (unsigned char Data) { char temp; LCD_Busy(); // Test if LCD Busy LCD_DIR_PORT = 0xFF; // LCD port output temp=LCD_OP_PORT; temp=temp&BIT3; LCD_OP_PORT =(Data & 0xf0)|temp; // Load high-data to port lcd_clear_rw() ; // Set LCD to write lcd_set_rs(); // Set LCD to data lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD LCD_OP_PORT = (Data << 4)|temp; // Load low-data to port lcd_clear_rw() ; // Set LCD to write lcd_set_rs(); // Set LCD to data lcd_set_e(); // Write data to LCD asm("nop"); asm("nop"); lcd_clear_e(); // Disable LCD } // ********************************* // // *** Initialize the LCD driver *** // // ********************************* // void Init_LCD(void) { LCD_INIT(); LCD_WriteControl (LCD_FUNCTION_SET); LCD_WriteControl (LCD_OFF); LCD_WriteControl (LCD_CLEAR); LCD_WriteControl (LCD_MODE_SET); LCD_WriteControl (LCD_ON); LCD_WriteControl (LCD_HOME); } // ************************************************ // // *** Clear the LCD screen (also homes cursor) *** // // ************************************************ // void LCD_Clear(void) { LCD_WriteControl(0x01); } // *********************************************** // // *** Position the LCD cursor at row 1, col 1 *** // // *********************************************** // void LCD_Home(void) { LCD_WriteControl(0x02); } // ****************************************************************** // // *** Display a single character, at the current cursor location *** // // ****************************************************************** // void LCD_DisplayCharacter (char Char) { LCD_WriteData (Char); } // ********************************************************************* // // *** Display a string at the specified row and column, using FLASH *** // // ********************************************************************* // void LCD_DisplayString_F (char row, char column , unsigned char __flash *string) { LCD_Cursor (row, column); while (*string) { LCD_DisplayCharacter (*string++); } } // ******************************************************************* // // *** Display a string at the specified row and column, using RAM *** // // ******************************************************************* // void LCD_DisplayString (char row, char column ,unsigned char *string) { LCD_Cursor (row, column); while (*string) LCD_DisplayCharacter (*string++); } // *************************************************** // // *** Position the LCD cursor at "row", "column". *** // // *************************************************** // void LCD_Cursor (char row, char column) { switch (row) { case 1: LCD_WriteControl (0x80 + column - 1); break; case 2: LCD_WriteControl (0xc0 + column - 1); break; case 3: LCD_WriteControl (0x94 + column - 1); break; case 4: LCD_WriteControl (0xd4 + column - 1); break; default: break; } } // ************************** // // *** Turn the cursor on *** // // ************************** // void LCD_Cursor_On (void) { LCD_WriteControl (LCD_CURS_ON); } // *************************** // // *** Turn the cursor off *** // // *************************** // void LCD_Cursor_Off (void) { LCD_WriteControl (LCD_ON); } // ******************** // // *** Turn Off LCD *** // // ******************** // void LCD_Display_Off (void) { LCD_WriteControl(LCD_OFF); } // ******************* // // *** Turn On LCD *** // // ******************* // void LCD_Display_On (void) { LCD_WriteControl(LCD_ON); }