Interfacing LCD with ATMEGA 8

[prajwal]

Hello friends,

 

Can i use the code LCD interfacing provided in Engineers garage for ATMEGA 8?

 

The circuit is given for ATMEGA 16… Should i modify the code fot ATMEGA 8?

 

Pls help…

[AJISH ALFRED]

Hi Prajwal,

Which code are you using, 4-bit mode or 8-bit mode?

Take the case of 4-bit mode, the LCD is entirely connected to portA of atmega16, but in atmega8 there is no portA.

You have to modify your code according to the microcontroller you are using.

[prajwal]

Thanks for the reply sir I will try it and post you back soon

[prajwal]

hello sir i modified the 4 bit mode code to atmega 8. the code is like this

 

 

#include<avr/io.h>
#include<util/delay.h>
#include<inttypes.h>
 
#define rs PB0    
#define rw PB1
#define en PB2
 
void lcd_init();
void dis_cmd(char);
void dis_data(char);
void lcdcmd(char);
void lcddata(char);
 
int main(void)
{
unsigned char data0[11]=”ENGINEERS”;
unsigned char data1[10]=”GARAGE”;
 
int i=0;
DDRD=0xFF;
lcd_init();
while(data0!=’’)
{
dis_data(data0);
_delay_ms(200);
i++;
}
 
dis_cmd(0xC5);
 
i=0;
while(data1!=’’)
{
dis_data(data1);
_delay_ms(200);
i++;
}
 
while(1);
}
 
 
 
void lcd_init()    // fuction for intialize
{
dis_cmd(0x02);    // to initialize LCD in 4-bit mode.
dis_cmd(0x28);    //to initialize LCD in 2 lines, 5X7 dots and 4bit mode.
dis_cmd(0x0C);
dis_cmd(0x06);
dis_cmd(0x83);
}
 
void dis_cmd(char cmd_value)
{
char cmd_value1;
cmd_value1 = cmd_value & 0xF0;    //mask lower nibble because PA4-PA7 pins are used.
lcdcmd(cmd_value1);    // send to LCD
 
cmd_value1 = ((cmd_value<<4) & 0xF0);    //shift 4-bit and mask
lcdcmd(cmd_value1);    // send to LCD
}    
 
 
void dis_data(char data_value)
{
char data_value1;
data_value1=data_value&0xF0;
lcddata(data_value1);
 
data_value1=((data_value<<4)&0xF0);
lcddata(data_value1);
}
 
void lcdcmd(char cmdout)
{
PORTD=cmdout;
PORTD&=~(1<<rs);
PORTD&=~(1<<rw);
PORTD|=(1<<en);
_delay_ms(1);
PORTD&=~(1<<en);
}
 
void lcddata(char dataout)
{
PORTD=dataout;
PORTD|=(1<<rs);
PORTD&=~(1<<rw);
PORTD|=(1<<en);
_delay_ms(1);
PORTD&=~(1<<en);
}

 

But the lcd is not displaying anything but just black boxes are appearing on LCD first row

 

Help pls…

[AJISH ALFRED]

So you are using PORTD right?

Then change the followinh lines:

#define rs PB0    
#define rw PB1
#define en PB2

 

as follows

 

#define rs PD0

#define rw PD1

#define en PD2

 

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