/* These pins are for PIC16F64A which is connected to Char 16*4 LCD module(SantechDosiplay C1604A) This data bus is 4bit-interface. Reference : CCS forum */ #define LCD_RS PIN_A1 #define LCD_RW PIN_A2 #define LCD_E PIN_A0 #define LCD_DB4 PIN_B4 //4bit interface #define LCD_DB5 PIN_B5 #define LCD_DB6 PIN_B6 #define LCD_DB7 PIN_B7 // If you want only a 6-pin interface to your LCD, then // connect the R/W pin on the LCD to ground, and comment // out the following line. Doing so will save one PIC // pin, but at the cost of losing the ability to read from // the LCD. It also makes the write time a little longer // because a static delay must be used, instead of polling // the LCD's busy bit. Normally a 6-pin interface is only // used if you are running out of PIC pins, and you need // to use as few as possible for the LCD. #define USE_RW_PIN 1 // These are the line addresses for most 16*4 LCDs. #define LCD_LINE_1_ADDRESS 0x00 #define LCD_LINE_2_ADDRESS 0x40 #define LCD_LINE_3_ADDRESS 0x10 #define LCD_LINE_4_ADDRESS 0x50 //======================================== #define lcd_type 2 //0=5x7, 1=5x10, 2=2 lines(or more) int8 lcd_line; //Number of LCD line int8 const LCD_INIT_STRING[4] = { 0x20 | (lcd_type << 2), // Function: 4-bit, 2-lines, 5x8 dots 0x0C, // Display on 1, // Clear display 6 // Increment cursor }; //------------------------------------- void lcd_send_nibble(int8 nibble) //Sends 4bit data { // Note: !! converts an integer expression to a boolean (1 or 0). output_bit(LCD_DB4, !!(nibble & 1)); output_bit(LCD_DB5, !!(nibble & 2)); output_bit(LCD_DB6, !!(nibble & 4)); output_bit(LCD_DB7, !!(nibble & 8)); delay_cycles(1); output_high(LCD_E); delay_us(2); output_low(LCD_E); } //----------------------------------- // This sub-routine is only called by lcd_read_byte(). // It's not a stand-alone routine. For example, the // R/W signal is set high by lcd_read_byte() before // this routine is called. #ifdef USE_RW_PIN int8 lcd_read_nibble(void) //reads 4bits data { int8 retval; // Create bit variables so that we can easily set // individual bits in the retval variable. #bit retval_0 = retval.0 #bit retval_1 = retval.1 #bit retval_2 = retval.2 #bit retval_3 = retval.3 retval = 0; output_high(LCD_E); delay_us(1); retval_0 = input(LCD_DB4); retval_1 = input(LCD_DB5); retval_2 = input(LCD_DB6); retval_3 = input(LCD_DB7); output_low(LCD_E); delay_us(1); return(retval); } #endif //--------------------------------------- // Read a byte from the LCD and return it. #ifdef USE_RW_PIN int8 lcd_read_byte(void) { int8 low; int8 high; output_high(LCD_RW); delay_cycles(1); high = lcd_read_nibble(); low = lcd_read_nibble(); return( (high<<4) | low); } #endif //---------------------------------------- // Send a byte to the LCD. void lcd_send_byte(int8 address, int8 n) //address=0--->command send, address!=0--->Display data send { output_low(LCD_RS); #ifdef USE_RW_PIN while(bit_test(lcd_read_byte(),7)) ; //Busy check #else delay_us(60); #endif if(address) output_high(LCD_RS); else output_low(LCD_RS); delay_cycles(1); #ifdef USE_RW_PIN output_low(LCD_RW); delay_cycles(1); #endif output_low(LCD_E); lcd_send_nibble(n >> 4); lcd_send_nibble(n & 0xf); } //---------------------------- void lcd_init(void) { int8 i; lcd_line = 1; output_low(LCD_RS); #ifdef USE_RW_PIN output_low(LCD_RW); #endif output_low(LCD_E); // Some LCDs require 15 ms minimum delay after // power-up. Others require 30 ms. I'm going // to set it to 35 ms, so it should work with // all of them. delay_ms(35); for(i=0 ;i < 3; i++) { lcd_send_nibble(0x03); //8bit mode set 3times without Busy check delay_ms(5); } lcd_send_nibble(0x02); //4bit mode set for(i=0; i < sizeof(LCD_INIT_STRING); i++) { lcd_send_byte(0, LCD_INIT_STRING[i]); //Functtion Set // If the R/W signal is not used, then // the busy bit can't be polled. One of // the init commands takes longer than // the hard-coded delay of 50 us, so in // that case, lets just do a 5 ms delay // after all four of them. #ifndef USE_RW_PIN delay_ms(5); #endif } } //---------------------------- void lcd_gotoxy(int8 x, int8 y) { int8 address; switch(y) { case 1: address = LCD_LINE_1_ADDRESS; break; case 2: address = LCD_LINE_2_ADDRESS; break; case 3: address = LCD_LINE_3_ADDRESS; break; case 4: address = LCD_LINE_4_ADDRESS; break; default: address = LCD_LINE_1_ADDRESS; break; } address += x-1; lcd_send_byte(0, 0x80 | address); } //----------------------------- void lcd_putc(char c) { switch(c) { case '\f': lcd_send_byte(0,1); //Clear Display lcd_line = 1; delay_ms(2); break; case '\n': lcd_gotoxy(1, ++lcd_line); //To the left side of New line break; case '\b': lcd_send_byte(0,0x10); //Decriment DDRAM Address break; default: lcd_send_byte(1,c); //Display charcter break; } } //------------------------------ #ifdef USE_RW_PIN char lcd_getc(int8 x, int8 y) { char value; lcd_gotoxy(x,y); // Wait until busy flag is low. while(bit_test(lcd_read_byte(),7)); //Busy Check output_high(LCD_RS); value = lcd_read_byte(); output_low(LCD_RS); return(value); } #endif const int Ext_char[8][8]={ { 0b00000, //DDRAM Address=0x00 0b00000, 0b00000, 0b00000, 0b00000, 0b00000, 0b00000, 0b11111 }, { 0b00000, //DDRAM Address=0x01 0b00000, 0b00000, 0b00000, 0b00000, 0b00000, 0b11111, 0b11111 }, { 0b00000, //DDRAM Address=0x02 0b00000, 0b00000, 0b00000, 0b00000, 0b11111, 0b11111, 0b11111 }, { 0b00000, //DDRAM Address=0x03 0b00000, 0b00000, 0b00000, 0b11111, 0b11111, 0b11111, 0b11111 }, { 0b00000, //DDRAM Address=0x04 0b00000, 0b00000, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111 }, { 0b00000, //DDRAM Address=0x05 0b00000, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111 }, { 0b00000, //DDRAM Address=0x06 0b11111, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111 }, { 0b11111, //DDRAM Address=0x07 0b11111, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111, 0b11111 } }; void ext_char_set() { //Set CGRAM (8 chracters made by user) int cmd,i,j; for (i=0;i<8;i++) { cmd=(i<<3) + 0b1000000; lcd_send_byte(0,cmd); for (j=0;j<8;j++) { lcd_send_byte(1,Ext_char[i][j]); } } }