16×2 LCD display not working propery..

[samynathan]

i am  using this code in atmega16…. lcd is not displaying anything… someone plz help me.

 

portb is control port

portd is data port

 

enable—pb2

rw—pb1

r/s—pb0

 

 

 

 

#include<avr/io.h>

#include<util/delay.h>

 

 

 

void main()

{

DDRD=0xFF;

DDRB=0x07;

 

{

 

{

PORTD=0x38;

PORTB=0b00000100;

_delay_ms(10000);

PORTB=0b00000000;

_delay_ms(10000);

 

}

 

 

 

{

PORTD=0x01;

PORTB=0b00000100;

_delay_ms(10000);

PORTB=0b00000000;

_delay_ms(10000);

 

 

}

 

 

 

 

{

PORTD=0x0E;

PORTB=0b00000100;

_delay_ms(10000);

PORTB=0b00000000;

_delay_ms(10000);

 

}

 

 

{

PORTD=0x80;

PORTB=0b00000100;

_delay_ms(10000);

PORTB=0b00000000;

_delay_ms(10000);

 

 

}

 

 

 

}

 

 

 

unsigned char *str=”ENGINEERS GARAGE”;

 

 

int i=0;

while(str!=’’)

{

 

PORTD=str;

PORTB=0b00000101;

_delay_ms(10000);

PORTB=0b00000001;

_delay_ms(10000);

i++;

  }

 

}

 

 

 

 

 

 

 

[AJISH ALFRED]

 

Have you checked your circuit connections properly.

Also there is no need to drive the r/w pin through the program. Since you are always writing into the LCD module, the r/w pin can be hardwired to ground.

[samynathan]

 

its working in four bit mde….. but not for above program which is in 8 bit mode…

 

 

 

 

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[Ashish Koujalgi]

Check your connections again. Use the reset pin to check for the working if all the connections are right. Connect the reset pin to the ground and remove. Should work fine if everything else is correctly bulit.

[AJISH ALFRED]

 

Hi,

 

Your lcd not even initialized.

Also note that the backlight is low and the contrast is set high.

If it works in four bit mode and the code is proper, there should be some issues with the remaining four pins while using in 8 bit mode. Check the connections of those pins.

[Amrith]

Hi, 

1. Recheck your hardware connections properly, take care that no data lines are getting sorted.

2. Try varying the variable resistor.

3. check whether you are following below steps to intialise LCD in the code

 

Command –> RS=0, RW=0, E=1

Data –> RS=1, RW=0, E=1

4. To Intilaise LCD in 8-Bit mode use command 0x38 in hex or 56 in decimal format.

[Amrith]

Hi, 

1. Recheck your hardware connections properly, take care that no data lines are getting sorted.

2. Try varying the variable resistor.

3. check whether you are following below steps to intialise LCD in the code

Command –> RS=0, RW=0, E=1

Data –> RS=1, RW=0, E=1

4. To Intilaise LCD in 8-Bit mode use command 0x38 in hex or 56 in decimal format.

[Nirav Tejani]

Hi samyanthan,

             your code is perfect.check your lcd wire connection with controller and check all pins carefully….whether any one shorts with another???

 

 

[mahendra singh]

connect ur VEE pin of LCD to ground nd check

[Jay]

I am also facing same problem.

My program is correct.

But, I still get no output on LCD.

It displays same as yours 1st line blank & 2nd line full.

Still found no solution to it.

Can’t detect where I am making mistake………

[Author]

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