LCD in 4 Bit Mode using atmega8

[Briez]

I want to use lcd in 4 bit mode using atmega8, and i am facing problems in that... Someone help me to sort out this problem.​

I am using 16x2 character LCD and my pin configurations are,

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LCD_DATA   > PORTD   (PD4,PD5,PD6,PD7)
Rs              > PC5
E               > PC4
 
my code is/ /****************************************************************************************************//
 
#define F_CPU 4000000UL
 
#include<avr/io.h>
#include<util/delay.h>
 
#define DATA PORTD
//#define RS PC5
//#define E PC4
void lcd_init(void)
{
    lcd_cmd(0x28);
        _delay_ms(25);
    lcd_cmd(0x01);
        _delay_ms(25);
    lcd_cmd(0x0E);
        _delay_ms(25);
    lcd_cmd(0x06);
        _delay_ms(25);
 
}
void lcd_cmd(unsigned int cmd)
{
    DATA=cmd & 0xF0;
    PORTC=(0<<PC5);//|(1<<PC4);
    PORTC=(1<<PC4);
    _delay_ms(25);
    PORTC=(0<<PC4);
    
    DATA=((cmd<<4) & 0xF0);
    PORTC=(0<<PC5);//|(1<<PC4);
    PORTC=(1<<PC4);
    _delay_ms(25);
    PORTC=(0<<PC4);
return;
}
void lcd_data1(unsigned char data1)
{
    DATA=data1 & 0xF0;
    PORTC=(1<<PC5);//|(1<<PC4);
    PORTC=(1<<PC4);
    _delay_ms(25);
    PORTC=(0<<PC4);
    
    DATA=((data1<<4) & 0xF0);
    PORTC=(1<<PC5);//|(1<<PC4);
    PORTC=(1<<PC4);
    _delay_ms(25);
    PORTC=(0<<PC4);
return;
}
 
int main(void)
{
    DDRD=0xFF;
    DDRC=0x30;
_delay_ms(2);
    lcd_init();
while(1)
    {
    _delay_ms(2);
    lcd_data1('B');
    }
return 0;   
}

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[internetuser2k12]

see page no 42, 43, 46 here http://www.sparkfun.com/datasheets/LCD/HD44780.pdf Check the delays.

 

[T3STY]

If you're willing to write your own driver then I'd suggest you to use a minimum of 50 micro-seconds delay for the Enable high state. But if you just need to use an LCD then you might want to check out the C driver I made:
https://www.edaboard.com/blog/1817/
p.s. I'm not sure the driver will work on atmega8 PICs, but it's almost all standard C so it should.

 

[alexan_e]

PORTC=(1<<PC4);
_delay_ms(25);
PORTC=(0<<PC4);

I would suggest you start by reading the bitwise operations tutorial http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=37871 because your code suggests that you don't have a good understanding of that.

Also refer to an AVR LCD library like **broken link removed**