/****************************************************************************
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) )
