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qmk-firmware/drivers/avr/hd44780.c

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/****************************************************************************
Title: HD44780U LCD library
Author: Peter Fleury <pfleury@gmx.ch> http://tinyurl.com/peterfleury
License: GNU General Public License Version 3
File: $Id: lcd.c,v 1.15.2.2 2015/01/17 12:16:05 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 <util/delay.h>
#include "hd44780.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() _delay_us(LCD_DELAY_ENABLE_PULSE)
# 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 0x2C /* |0|010|1100 4-bit mode, extension-bit RE = 1 */
# define KS0073_EXTENDED_FUNCTION_REGISTER_OFF 0x28 /* |0|010|1000 4-bit mode, extension-bit RE = 0 */
# define KS0073_4LINES_MODE 0x09 /* |0|000|1001 4 lines mode */
# endif
#endif
/*
** function prototypes
*/
#if LCD_IO_MODE
static void toggle_e(void);
#endif
/*
** local functions
*/
/*************************************************************************
delay for a minimum of <us> microseconds
the number of loops is calculated at compile-time from MCU clock frequency
*************************************************************************/
#define delay(us) _delay_us(us)
#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(); /* RW=0 write 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)) {
/* 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(LCD_DELAY_BUSY_FLAG);
/* 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(LCD_DELAY_BOOTUP); /* wait 16ms or more after power-on */
/* initial write to lcd is 8bit */
LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN); // LCD_FUNCTION>>4;
LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN); // LCD_FUNCTION_8BIT>>4;
lcd_e_toggle();
delay(LCD_DELAY_INIT); /* delay, busy flag can't be checked here */
/* repeat last command */
lcd_e_toggle();
delay(LCD_DELAY_INIT_REP); /* delay, busy flag can't be checked here */
/* repeat last command a third time */
lcd_e_toggle();
delay(LCD_DELAY_INIT_REP); /* 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(LCD_DELAY_INIT_4BIT); /* 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(LCD_DELAY_BOOTUP); /* wait 16ms after power-on */
lcd_write(LCD_FUNCTION_8BIT_1LINE, 0); /* function set: 8bit interface */
delay(LCD_DELAY_INIT); /* wait 5ms */
lcd_write(LCD_FUNCTION_8BIT_1LINE, 0); /* function set: 8bit interface */
delay(LCD_DELAY_INIT_REP); /* wait 64us */
lcd_write(LCD_FUNCTION_8BIT_1LINE, 0); /* function set: 8bit interface */
delay(LCD_DELAY_INIT_REP); /* 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 */
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