interfacing 8×2 lcd with pic18f883

[kiran kumar]

Hi,

    

     I am trying to run a sample code of 16×2 lcd with pic18f887 by making some changes with respect to my own circuit like interfacing 8×2 lcd with pic18f883 using 4bit mode.

 

Things completed: changed pin config, XTAL_FREQ,  with respect to my micro controller and also successfully compiled

 

Problem faced : blank (no) output.

 

please help me .

 

KIRAN KUMAR

 

 

[kiran kumar]

*******************MAIN.C*****************************

 

 

#include<htc.h>

__CONFIG(LVP_OFF & FCMEN_OFF & IESO_OFF & BOREN_OFF & PWRTE_ON & WDTE_OFF & FOSC_HS);

#define RS RA5

#define EN RA4

#define D4 RC0

#define D5 RC1

#define D6 RC2

#define D7 RC3

 

 

#define _XTAL_FREQ 4000000

#include “lcd.h”

 

 

 

void main()

{

 int i;

  TRISA = 0X00;

  TRISC = 0x00;

  Lcd4_Init();

  while(1)

  {

    Lcd4_Set_Cursor(1,1);

    Lcd4_Write_String(“electroSome LCD Hello World”);

    for(i=0;i<15;i++)

    {

      __delay_ms(1000);

      Lcd4_Shift_Left();

    }

    for(i=0;i<15;i++)

    {

      __delay_ms(1000);

      Lcd4_Shift_Right();

    }

    Lcd4_Clear();

    Lcd4_Set_Cursor(2,1);

//Lcd4_Write_String(“electroSome LCD Hello World”);

    Lcd4_Write_Char(‘e’);

    Lcd4_Write_Char(‘S’);

    __delay_ms(2000);

  }

}

 

 

 

*********************************LCD.H*******************************************

 

 

 

 

//LCD Functions Developed by electroSome

 

 

 

#ifndef D0

#define D0 RB0

#define D1 RB1

#define D2 RB2

#define D3 RB3

#endif

 

 

//LCD 8 Bit Interfacing Functions

void Lcd8_Port(char a)

{

if(a & 1)

D0 = 1;

else 

D0 = 0;

 

if(a & 2)

D1 = 1;

else

D1 = 0;

 

if(a & 4)

D2 = 1;

else

D2 = 0;

 

if(a &

D3 = 1;

else

D3 = 0;

 

if(a & 16)

D4 = 1;

else

D4 = 0;

 

if(a & 32)

D5 = 1;

else

D5 = 0;

 

if(a & 64)

D6 = 1;

else 

D6 = 0;

 

if(a & 128)

D7 = 1;

else

D7 = 0;

}

void Lcd8_Cmd(char a)

{ 

  RS = 0;             // => RS = 0

  Lcd8_Port(a);             //Data transfer

  EN  = 1;             // => E = 1

  __delay_ms(5);

  EN  = 0;             // => E = 0

}

 

Lcd8_Clear()

{

 Lcd8_Cmd(1);

}

 

void Lcd8_Set_Cursor(char a, char b)

{

if(a == 1)

 Lcd8_Cmd(0x80 + b);

else if(a == 2)

Lcd8_Cmd(0xC0 + b);

}

 

void Lcd8_Init()

{

Lcd8_Port(0x00);

RS = 0;

__delay_ms(25);

///////////// Reset process from datasheet /////////

  Lcd8_Cmd(0x30);

__delay_ms(5);

  Lcd8_Cmd(0x30);

__delay_ms(15);

  Lcd8_Cmd(0x30);

  /////////////////////////////////////////////////////

  Lcd8_Cmd(0x38);    //function set

  Lcd8_Cmd(0x0C);    //display on,cursor off,blink off

  Lcd8_Cmd(0x01);    //clear display

  Lcd8_Cmd(0x06);    //entry mode, set increment

}

 

void Lcd8_Write_Char(char a)

{

   RS = 1;             // => RS = 1

   Lcd8_Port(a);             //Data transfer

   EN  = 1;             // => E = 1

  __delay_ms(4);

   EN  = 0;             // => E = 04

}

 

void Lcd8_Write_String(char *a)

{

int i;

for(i=0;a!=’’;i++)

Lcd8_Write_Char(a);

}

 

void Lcd8_Shift_Right()

{

Lcd8_Cmd(0x1C);

}

 

void Lcd8_Shift_Left()

{

Lcd8_Cmd(0x18);

}

//End LCD 8 Bit Interfacing Functions

 

//LCD 4 Bit Interfacing Functions

 

void Lcd4_Port(char a)

{

if(a & 1)

D4 = 1;

else 

D4 = 0;

 

if(a & 2)

D5 = 1;

else

D5 = 0;

 

if(a & 4)

D6 = 1;

else

D6 = 0;

 

if(a &

D7 = 1;

else

D7 = 0;

}

void Lcd4_Cmd(char a)

{ 

RS = 0;             // => RS = 0

Lcd4_Port(a);

EN  = 1;             // => E = 1

  __delay_ms(4);

  EN  = 0;             // => E = 0

}

 

Lcd4_Clear()

{

Lcd4_Cmd(0);

Lcd4_Cmd(1);

}

 

void Lcd4_Set_Cursor(char a, char b)

{

char temp,z,y;

if(a == 1)

{

 temp = 0x80 + b;

z = temp>>4;

y = (0x80+b) & 0x0F;

Lcd4_Cmd(z);

Lcd4_Cmd(y);

}

else if(a == 2)

{

temp = 0xC0 + b;

z = temp>>4;

y = (0xC0+b) & 0x0F;

Lcd4_Cmd(z);

Lcd4_Cmd(y);

}

}

 

void Lcd4_Init()

{

Lcd4_Port(0x00);

   __delay_ms(20);

  Lcd4_Cmd(0x03);

__delay_ms(5);

  Lcd4_Cmd(0x03);

__delay_ms(11);

  Lcd4_Cmd(0x03);

  /////////////////////////////////////////////////////

  Lcd4_Cmd(0x02);    

Lcd4_Cmd(0x02);

  Lcd4_Cmd(0x08);

Lcd4_Cmd(0x00); 

Lcd4_Cmd(0x0C);     

  Lcd4_Cmd(0x00);    

  Lcd4_Cmd(0x06);   

}

 

void Lcd4_Write_Char(char a)

{

   char temp,y;

   temp = a&0x0F; 

   y = a&0xF0;

RS = 1;             // => RS = 1

   Lcd4_Port(y>>4);             //Data transfer

EN = 1;

__delay_ms(5);

EN = 0;

Lcd4_Port(temp);

EN = 1;

__delay_ms(5);

EN = 0;

}

 

void Lcd4_Write_String(char *a)

{

int i;

for(i=0;a!=’’;i++)

Lcd4_Write_Char(a);

}

 

void Lcd4_Shift_Right()

{

Lcd4_Cmd(0x01);

Lcd4_Cmd(0x0C);

}

 

void Lcd4_Shift_Left()

{

Lcd4_Cmd(0x01);

Lcd4_Cmd(0x08);

}

//End LCD 4 Bit Interfacing Functions

 

 

PLEASE GIVE ME ANY SOLUTION

 

[Ashutosh Bhatt]

everything seems OK.

the problem may be the lcd.h file may not have been included

or there may be some problem in initializing 4-bit LCD mode

first try simple 8 bit mode then go for 4-bit mode

[kiran kumar]

Thank you for the reply Mr Bhatt, 

 

Is there any change in command or code with respect to the 8×2 and 16×2?

 

[Ashutosh Bhatt]

the only change in displaying characters. all other things remains same

[kiran kumar]

Thank you Mr Bhatt.

[Author]

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