/**************************************************************************** Title : HD44780U LCD library Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury File: $Id: lcd.c,v 1.14.2.1 2006/01/29 12:16:41 peter Exp $ Software: AVR-GCC 3.3 Target: any AVR device, memory mapped mode only for AT90S4414/8515/Mega DESCRIPTION Basic routines for interfacing a HD44780U-based text lcd display Originally based on Volker Oth's lcd library, changed lcd_init(), added additional constants for lcd_command(), added 4-bit I/O mode, improved and optimized code. Library can be operated in memory mapped mode (LCD_IO_MODE=0) or in 4-bit IO port mode (LCD_IO_MODE=1). 8-bit IO port mode not supported. Memory mapped mode compatible with Kanda STK200, but supports also generation of R/W signal through A8 address line. USAGE See the C include lcd.h file for a description of each function *****************************************************************************/ #include <inttypes.h> #include <avr/io.h> #include <avr/pgmspace.h> #include "lcd.h" /* ** constants/macros */ #define DDR(x) (*(&x - 1)) /* address of data direction register of port x */ #if defined(__AVR_ATmega64__) || defined(__AVR_ATmega128__) /* on ATmega64/128 PINF is on port 0x00 and not 0x60 */ #define PIN(x) ( &PORTF==&(x) ? _SFR_IO8(0x00) : (*(&x - 2)) ) #else #define PIN(x) (*(&x - 2)) /* address of input register of port x */ #endif #if LCD_IO_MODE #define lcd_e_delay() __asm__ __volatile__( "rjmp 1f\n 1:" ); #define lcd_e_high() LCD_E_PORT |= _BV(LCD_E_PIN); #define lcd_e_low() LCD_E_PORT &= ~_BV(LCD_E_PIN); #define lcd_e_toggle() toggle_e() #define lcd_rw_high() LCD_RW_PORT |= _BV(LCD_RW_PIN) #define lcd_rw_low() LCD_RW_PORT &= ~_BV(LCD_RW_PIN) #define lcd_rs_high() LCD_RS_PORT |= _BV(LCD_RS_PIN) #define lcd_rs_low() LCD_RS_PORT &= ~_BV(LCD_RS_PIN) #endif #if LCD_IO_MODE #if LCD_LINES==1 #define LCD_FUNCTION_DEFAULT LCD_FUNCTION_4BIT_1LINE #else #define LCD_FUNCTION_DEFAULT LCD_FUNCTION_4BIT_2LINES #endif #else #if LCD_LINES==1 #define LCD_FUNCTION_DEFAULT LCD_FUNCTION_8BIT_1LINE #else #define LCD_FUNCTION_DEFAULT LCD_FUNCTION_8BIT_2LINES #endif #endif #if LCD_CONTROLLER_KS0073 #if LCD_LINES==4 #define KS0073_EXTENDED_FUNCTION_REGISTER_ON 0x24 /* |0|010|0100 4-bit mode extension-bit RE = 1 */ #define KS0073_EXTENDED_FUNCTION_REGISTER_OFF 0x20 /* |0|000|1001 4 lines mode */ #define KS0073_4LINES_MODE 0x09 /* |0|001|0000 4-bit mode, extension-bit RE = 0 */ #endif #endif /* ** function prototypes */ #if LCD_IO_MODE static void toggle_e(void); #endif /* ** local functions */ /************************************************************************* delay loop for small accurate delays: 16-bit counter, 4 cycles/loop *************************************************************************/ static inline void _delayFourCycles(unsigned int __count) { if ( __count == 0 ) __asm__ __volatile__( "rjmp 1f\n 1:" ); // 2 cycles else __asm__ __volatile__ ( "1: sbiw %0,1" "\n\t" "brne 1b" // 4 cycles/loop : "=w" (__count) : "0" (__count) ); } /************************************************************************* delay for a minimum of <us> microseconds the number of loops is calculated at compile-time from MCU clock frequency *************************************************************************/ #define delay(us) _delayFourCycles( ( ( 1*(XTAL/4000) )*us)/1000 ) #if LCD_IO_MODE /* toggle Enable Pin to initiate write */ static void toggle_e(void) { lcd_e_high(); lcd_e_delay(); lcd_e_low(); } #endif /************************************************************************* Low-level function to write byte to LCD controller Input: data byte to write to LCD rs 1: write data 0: write instruction Returns: none *************************************************************************/ #if LCD_IO_MODE static void lcd_write(uint8_t data,uint8_t rs) { unsigned char dataBits ; if (rs) { /* write data (RS=1, RW=0) */ lcd_rs_high(); } else { /* write instruction (RS=0, RW=0) */ lcd_rs_low(); } lcd_rw_low(); if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT ) && (LCD_DATA0_PIN == 0) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) ) { /* configure data pins as output */ DDR(LCD_DATA0_PORT) |= 0x0F; /* output high nibble first */ dataBits = LCD_DATA0_PORT & 0xF0; LCD_DATA0_PORT = dataBits |((data>>4)&0x0F); lcd_e_toggle(); /* output low nibble */ LCD_DATA0_PORT = dataBits | (data&0x0F); lcd_e_toggle(); /* all data pins high (inactive) */ LCD_DATA0_PORT = dataBits | 0x0F; } else { /* configure data pins as output */ DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN); DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN); DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN); DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN); /* output high nibble first */ LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN); LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN); LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN); LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN); if(data & 0x80) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN); if(data & 0x40) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN); if(data & 0x20) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN); if(data & 0x10) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN); lcd_e_toggle(); /* output low nibble */ LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN); LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN); LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN); LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN); if(data & 0x08) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN); if(data & 0x04) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN); if(data & 0x02) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN); if(data & 0x01) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN); lcd_e_toggle(); /* all data pins high (inactive) */ LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN); LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN); LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN); LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN); } } #else #define lcd_write(d,rs) if (rs) *(volatile uint8_t*)(LCD_IO_DATA) = d; else *(volatile uint8_t*)(LCD_IO_FUNCTION) = d; /* rs==0 -> write instruction to LCD_IO_FUNCTION */ /* rs==1 -> write data to LCD_IO_DATA */ #endif /************************************************************************* Low-level function to read byte from LCD controller Input: rs 1: read data 0: read busy flag / address counter Returns: byte read from LCD controller *************************************************************************/ #if LCD_IO_MODE static uint8_t lcd_read(uint8_t rs) { uint8_t data; if (rs) lcd_rs_high(); /* RS=1: read data */ else lcd_rs_low(); /* RS=0: read busy flag */ lcd_rw_high(); /* RW=1 read mode */ if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT ) && ( LCD_DATA0_PIN == 0 )&& (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) ) { DDR(LCD_DATA0_PORT) &= 0xF0; /* configure data pins as input */ lcd_e_high(); lcd_e_delay(); data = PIN(LCD_DATA0_PORT) << 4; /* read high nibble first */ lcd_e_low(); lcd_e_delay(); /* Enable 500ns low */ lcd_e_high(); lcd_e_delay(); data |= PIN(LCD_DATA0_PORT)&0x0F; /* read low nibble */ lcd_e_low(); } else { /* configure data pins as input */ DDR(LCD_DATA0_PORT) &= ~_BV(LCD_DATA0_PIN); DDR(LCD_DATA1_PORT) &= ~_BV(LCD_DATA1_PIN); DDR(LCD_DATA2_PORT) &= ~_BV(LCD_DATA2_PIN); DDR(LCD_DATA3_PORT) &= ~_BV(LCD_DATA3_PIN); /* read high nibble first */ lcd_e_high(); lcd_e_delay(); data = 0; if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x10; if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x20; if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x40; if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x80; lcd_e_low(); lcd_e_delay(); /* Enable 500ns low */ /* read low nibble */ lcd_e_high(); lcd_e_delay(); if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x01; if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x02; if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x04; if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x08; lcd_e_low(); } return data; } #else #define lcd_read(rs) (rs) ? *(volatile uint8_t*)(LCD_IO_DATA+LCD_IO_READ) : *(volatile uint8_t*)(LCD_IO_FUNCTION+LCD_IO_READ) /* rs==0 -> read instruction from LCD_IO_FUNCTION */ /* rs==1 -> read data from LCD_IO_DATA */ #endif /************************************************************************* loops while lcd is busy, returns address counter *************************************************************************/ static uint8_t lcd_waitbusy(void) { register uint8_t c; /* wait until busy flag is cleared */ while ( (c=lcd_read(0)) & (1<<LCD_BUSY)) {} /* the address counter is updated 4us after the busy flag is cleared */ delay(2); /* now read the address counter */ return (lcd_read(0)); // return address counter }/* lcd_waitbusy */ /************************************************************************* Move cursor to the start of next line or to the first line if the cursor is already on the last line. *************************************************************************/ static inline void lcd_newline(uint8_t pos) { register uint8_t addressCounter; #if LCD_LINES==1 addressCounter = 0; #endif #if LCD_LINES==2 if ( pos < (LCD_START_LINE2) ) addressCounter = LCD_START_LINE2; else addressCounter = LCD_START_LINE1; #endif #if LCD_LINES==4 #if KS0073_4LINES_MODE if ( pos < LCD_START_LINE2 ) addressCounter = LCD_START_LINE2; else if ( (pos >= LCD_START_LINE2) && (pos < LCD_START_LINE3) ) addressCounter = LCD_START_LINE3; else if ( (pos >= LCD_START_LINE3) && (pos < LCD_START_LINE4) ) addressCounter = LCD_START_LINE4; else addressCounter = LCD_START_LINE1; #else if ( pos < LCD_START_LINE3 ) addressCounter = LCD_START_LINE2; else if ( (pos >= LCD_START_LINE2) && (pos < LCD_START_LINE4) ) addressCounter = LCD_START_LINE3; else if ( (pos >= LCD_START_LINE3) && (pos < LCD_START_LINE2) ) addressCounter = LCD_START_LINE4; else addressCounter = LCD_START_LINE1; #endif #endif lcd_command((1<<LCD_DDRAM)+addressCounter); }/* lcd_newline */ /* ** PUBLIC FUNCTIONS */ /************************************************************************* Send LCD controller instruction command Input: instruction to send to LCD controller, see HD44780 data sheet Returns: none *************************************************************************/ void lcd_command(uint8_t cmd) { lcd_waitbusy(); lcd_write(cmd,0); } /************************************************************************* Send data byte to LCD controller Input: data to send to LCD controller, see HD44780 data sheet Returns: none *************************************************************************/ void lcd_data(uint8_t data) { lcd_waitbusy(); lcd_write(data,1); } /************************************************************************* Set cursor to specified position Input: x horizontal position (0: left most position) y vertical position (0: first line) Returns: none *************************************************************************/ void lcd_gotoxy(uint8_t x, uint8_t y) { #if LCD_LINES==1 lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x); #endif #if LCD_LINES==2 if ( y==0 ) lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x); else lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x); #endif #if LCD_LINES==4 if ( y==0 ) lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x); else if ( y==1) lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x); else if ( y==2) lcd_command((1<<LCD_DDRAM)+LCD_START_LINE3+x); else /* y==3 */ lcd_command((1<<LCD_DDRAM)+LCD_START_LINE4+x); #endif }/* lcd_gotoxy */ /************************************************************************* *************************************************************************/ int lcd_getxy(void) { return lcd_waitbusy(); } /************************************************************************* Clear display and set cursor to home position *************************************************************************/ void lcd_clrscr(void) { lcd_command(1<<LCD_CLR); } /************************************************************************* Set cursor to home position *************************************************************************/ void lcd.home(void) { lcd_command(1<<LCD_HOME); } /************************************************************************* Display character at current cursor position Input: character to be displayed Returns: none *************************************************************************/ void lcd_putc(char c) { uint8_t pos; pos = lcd_waitbusy(); // read busy-flag and address counter if (c=='\n') { lcd_newline(pos); } else { #if LCD_WRAP_LINES==1 #if LCD_LINES==1 if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) { lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0); } #elif LCD_LINES==2 if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) { lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0); }else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH ){ lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0); } #elif LCD_LINES==4 if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) { lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0); }else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH ) { lcd_write((1<<LCD_DDRAM)+LCD_START_LINE3,0); }else if ( pos == LCD_START_LINE3+LCD_DISP_LENGTH ) { lcd_write((1<<LCD_DDRAM)+LCD_START_LINE4,0); }else if ( pos == LCD_START_LINE4+LCD_DISP_LENGTH ) { lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0); } #endif lcd_waitbusy(); #endif lcd_write(c, 1); } }/* lcd_putc */ /************************************************************************* Display string without auto linefeed Input: string to be displayed Returns: none *************************************************************************/ void lcd_puts(const char *s) /* print string on lcd (no auto linefeed) */ { register char c; while ( (c = *s++) ) { lcd_putc(c); } }/* lcd_puts */ /************************************************************************* Display string from program memory without auto linefeed Input: string from program memory be be displayed Returns: none *************************************************************************/ void lcd_puts_p(const char *progmem_s) /* print string from program memory on lcd (no auto linefeed) */ { register char c; while ( (c = pgm_read_byte(progmem_s++)) ) { lcd_putc(c); } }/* lcd_puts_p */ /************************************************************************* Initialize display and select type of cursor Input: dispAttr LCD_DISP_OFF display off LCD_DISP_ON display on, cursor off LCD_DISP_ON_CURSOR display on, cursor on LCD_DISP_CURSOR_BLINK display on, cursor on flashing Returns: none *************************************************************************/ void lcd_init(uint8_t dispAttr) { #if LCD_IO_MODE /* * Initialize LCD to 4 bit I/O mode */ if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT ) && ( &LCD_RS_PORT == &LCD_DATA0_PORT) && ( &LCD_RW_PORT == &LCD_DATA0_PORT) && (&LCD_E_PORT == &LCD_DATA0_PORT) && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) && (LCD_RS_PIN == 4 ) && (LCD_RW_PIN == 5) && (LCD_E_PIN == 6 ) ) { /* configure all port bits as output (all LCD lines on same port) */ DDR(LCD_DATA0_PORT) |= 0x7F; } else if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT ) && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) ) { /* configure all port bits as output (all LCD data lines on same port, but control lines on different ports) */ DDR(LCD_DATA0_PORT) |= 0x0F; DDR(LCD_RS_PORT) |= _BV(LCD_RS_PIN); DDR(LCD_RW_PORT) |= _BV(LCD_RW_PIN); DDR(LCD_E_PORT) |= _BV(LCD_E_PIN); } else { /* configure all port bits as output (LCD data and control lines on different ports */ DDR(LCD_RS_PORT) |= _BV(LCD_RS_PIN); DDR(LCD_RW_PORT) |= _BV(LCD_RW_PIN); DDR(LCD_E_PORT) |= _BV(LCD_E_PIN); DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN); DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN); DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN); DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN); } delay(16000); /* wait 16ms or more after power-on */ /* initial write to lcd is 8bit */ LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN); // _BV(LCD_FUNCTION)>>4; LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN); // _BV(LCD_FUNCTION_8BIT)>>4; lcd_e_toggle(); delay(4992); /* delay, busy flag can't be checked here */ /* repeat last command */ lcd_e_toggle(); delay(64); /* delay, busy flag can't be checked here */ /* repeat last command a third time */ lcd_e_toggle(); delay(64); /* delay, busy flag can't be checked here */ /* now configure for 4bit mode */ LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN); // LCD_FUNCTION_4BIT_1LINE>>4 lcd_e_toggle(); delay(64); /* some displays need this additional delay */ /* from now the LCD only accepts 4 bit I/O, we can use lcd_command() */ #else /* * Initialize LCD to 8 bit memory mapped mode */ /* enable external SRAM (memory mapped lcd) and one wait state */ MCUCR = _BV(SRE) | _BV(SRW); /* reset LCD */ delay(16000); /* wait 16ms after power-on */ lcd_write(LCD_FUNCTION_8BIT_1LINE,0); /* function set: 8bit interface */ delay(4992); /* wait 5ms */ lcd_write(LCD_FUNCTION_8BIT_1LINE,0); /* function set: 8bit interface */ delay(64); /* wait 64us */ lcd_write(LCD_FUNCTION_8BIT_1LINE,0); /* function set: 8bit interface */ delay(64); /* wait 64us */ #endif #if KS0073_4LINES_MODE /* Display with KS0073 controller requires special commands for enabling 4 line mode */ lcd_command(KS0073_EXTENDED_FUNCTION_REGISTER_ON); lcd_command(KS0073_4LINES_MODE); lcd_command(KS0073_EXTENDED_FUNCTION_REGISTER_OFF); #else lcd_command(LCD_FUNCTION_DEFAULT); /* function set: display lines */ #endif lcd_command(LCD_DISP_OFF); /* display off */ lcd_clrscr(); /* display clear */ lcd_command(LCD_MODE_DEFAULT); /* set entry mode */ lcd_command(dispAttr); /* display/cursor control */ }/* lcd_init */