LCD shift right and shift left bugs - c

Question

I have made a library for LCD with HD44780 controller in it, and from the datasheet I read that the code 0x18 will shift the entire display one position to the left, but when I made that, the display disappears.
I have also read that 0x1C shifts the entire display one position to the right but when I made it, the entire display shifts to left.
My code:
/*
* main.c
*
* Created: 11/14/2013 7:54:02 PM
* Author: A R M T
*/
#include <avr/io.h>
#define F_CPU 1000000UL
#define __DELAY_BACKWARD_COMPATIBLE__
#include <util/delay.h>
#define LCD_DPRT PORTA //LCD DATA PORT
#define LCD_DDDR DDRA //LCD DATA DDR
#define LCD_DPIN PINA //LCD DATA PIN
#define LCD_CPRT PORTB //LCD COMMANDS PORT
#define LCD_CDDR DDRB //LCD COMMANDS DDR
#define LCD_CPIN PINB //LCD COMMANDS PIN
#define LCD_RS 0 //LCD RS
#define LCD_RW 1 //LCD RW
#define LCD_EN 2 //LCD EN
//*************************************************************
void delay_us(unsigned int d);
void lcdCommand(unsigned char cmnd);
void lcdData(unsigned char data);
void lcd_init(void);
void lcd_gotoxy(unsigned char x, unsigned char y);
void lcd_print(char *str);
//*************************************************************
void delay_us(unsigned int d)
{
_delay_us(d);
}
//*************************************************************
void lcdCommand(unsigned char cmnd)
{
LCD_DPRT = cmnd; //send cmnd to data port
LCD_CPRT &= ~(1<<LCD_RS); //RS = 0 for command
LCD_CPRT &= ~(1<<LCD_RW); //RW = 0 for write
LCD_CPRT |= (1<<LCD_EN); //EN = 1 for H-to-l pulse
delay_us(1); //Wait to make enable wide
LCD_CPRT &= ~(1<<LCD_EN); //EN = 1 for H-to-l pulse
delay_us(100); //Wait to make enable wide
}
//*************************************************************
void lcdData(unsigned char data)
{
LCD_DPRT = data; //send data to data port
LCD_CPRT |= (1<<LCD_RS); //RS = 1 for data
LCD_CPRT &= ~(1<<LCD_RW); //RW = 0 for write
LCD_CPRT |= (1<<LCD_EN); //EN = 1 for H-to-L pulse
delay_us(1); //wait to make enable wide
LCD_CPRT &= ~(1<<LCD_EN); //EN = 0 for H-to-L pulse
delay_us(100); //wait to make enable wide
}
//*************************************************************
void lcd_init(void)
{
LCD_DDDR = 0xFF;
LCD_CDDR = 0xFF;
LCD_CPRT &= ~(1<<LCD_EN); //LCD_EN = 0
delay_us(15000); //wait for init
lcdCommand(0x38); //init. LCD 2 line, 5 * 7 matrix
lcdCommand(0x0E); //display on, cursor on
lcdCommand(0x01); //clear LCD
delay_us(2000); //wait
lcdCommand(0x06); //shift cursor right
}
//*************************************************************
void lcd_gotoxy(unsigned char x, unsigned char y)
{
unsigned char firstCharAdr[] = {0x80, 0xC0, 0x94, 0xD4};
lcdCommand(firstCharAdr[y-1] + x - 1);
delay_us(100);
}
//*************************************************************
void lcd_print(char *str)
{
unsigned char i = 0;
while (str[i] != 0)
{
lcdData(str[i]);
i++;
}
}
//*************************************************************
int main(void)
{
lcd_init();
lcd_gotoxy(1,1);
lcd_print("Armia");
lcd_gotoxy(1,2);
lcd_print("Wagdy");
_delay_ms(1000 / 2);
lcdCommand(0x18); // Shift the entire display one position to the left
while(1);
return 0;
}
I meant that when I burned this code I excepected that aftr(1000 / 2) ms this output will shift to left
but what appears was(the word disappears instead of shifting left one postition)
Can any one help me in that problem please?!

Answer 1

I tried your code in proteus version 7.10 and shift left works fine
Note that you are using the _delay_us function with a variable parameter, that is not the correct way, it gives wrong delays and generates big hex file because it forces the float library to be included
delay.h manual
Note:
In order for these functions to work as intended, compiler optimizations must be enabled, and the delay time must be an
expression that is a known constant at compile-time. If these
requirements are not met, the resulting delay will be much longer (and
basically unpredictable), and applications that otherwise do not use
floating-point calculations will experience severe code bloat by the
floating-point library routines linked into the application.
Replace the code with a loop that calls the delay several times
while (d--)
{
_delay_ms(1);
}