Problem in interfacing LCD

[Laxman Kumar]

I am using P89V51RD2 microcontroller and trying to interface with 16x2 LCD (jhd162a)...but not able to get a single character on LCD...
here is the code i am using...what is the problem....

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#include<reg51.h> // include header file
#define msec 50    // definition for delay
sbit rs=P3^0;   //Register select (RS)
sbit rw=P3^1;   //Read write (RW) pin
sbit en=P3^6;   //Enable (EN) pin
unsigned char commands[]={0x38,0x0E,0x01,0x06,'\0'};  //Command to be sent to LCD (initializing)
char name[]={"microcontroller 8051"};    //String to be displayed on LCD
 
void delay(unsigned int time)  //Time delay function
{
unsigned int i,j;
for(i=0;i<time;i++)
  for(j=0;j<1275;j++);
}
 
void lcdcmd(unsigned char value)  //Function for sending values to the command register of LCD
{
P2=value;
rs=0;
rw=0;
en=1;
delay(1);
en=0;
return;
}
 
void display(unsigned char value)  //Function for sending values to the data register of LCD
{
P2=value;
rs=1;
rw=0;
en=1;
delay(1);
en=0;
return;
}
 
void main()
{
int i,j;
for(i=0;commands[i]!='\0';i++)  //Sending string to LCD
{
  lcdcmd(commands[i]);
  delay(msec);
}
for(j=0;name[j]!='\0';j++)
{
  display(name[j]);
  delay(msec);
}
while(1)
{
  lcdcmd(0x18);  //Shift the entire display to right
  delay(75);
}
}

---

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[embRTS]

Hi Laxman you do first a basic thing
the data lines which you are using to sending that data or the pins/port connected to RS, EN & RW ,

First declare all them(PORTs) as OUTPUT in your main function ,

and instead of Printing a String at the first time try with the the displaying of only 1 character like 'A' using the function

display('A') ;   // as the function has prototype for the same

Then if that is perfect then go for Printing a String and further moving it to left or RIGHT ,
if there is still problem upload for the same !!

 

[Raady Here]

you have initialized the LCD, sending the data, but you haven't mentioned where to place the data

 

[Laxman Kumar]

you have initialized the LCD, sending the data, but you haven't mentioned where to place the data

how to do that so????

- - - Updated - - -

Hi Laxman you do first a basic thing
the data lines which you are using to sending that data or the pins/port connected to RS, EN & RW ,

First declare all them(PORTs) as OUTPUT in your main function ,

and instead of Printing a String at the first time try with the the displaying of only 1 character like 'A' using the function

display('A') ;   // as the function has prototype for the same

Then if that is perfect then go for Printing a String and further moving it to left or RIGHT ,
if there is still problem upload for the same !!

how to set ports as output????

 

[nick703]

Read this Blog bro!!!

https://saeedsolutions.blogspot.in/2012/05/8051-lcd-interfacing-code-in-4bit-mode.html?q=8051

 

[JAMAL JIMI]

Hi.......You can make the ports as output by writing a "0" to them and also set the DDRAM address to of the lcd which is following for first and 2nd line respectively.....

First line=0x80 to 0x8F
2nd line=0xC0 to 0xCF

 

[embRTS]

As Jamal said suppose you have assigned
PORT2 as data lines then declare PORT2 as Output

also Three PINS which are being used for RS , ENable, and RW make them also as OUTPUT,

in The main FUnction

first do like that

PORT2 = 0x00 ; //output
PORT1 = 0b11111000 ; //MAKING 1st , 2nd and 3rd pins of PORT 1 as Output

//You can use any PORT or Pins as per your Convenience OR as per Your CIRCUIT Diagram

then Only Apply the Function

LCD_init();

then first check for 1 data display

with display Function like diplay('M');

if it is working then make a function to print a string using POinters so that address increments

void LCD_string(unsigned char *mystring)
{
while(*mystring !=  '\0'  )
{
display(*mystring)  ;
mystring++ ; 
}
}

and use it like 
LCD_string("EMBEDDED WORLD");  //this will print the string

- - - Updated - - -

Hi .
as per your PCB I think PORT0 is assigned for Data , PORT2 1st three PINS are assigned for RS , RW and Enable

So declare

PORT0 = 0x00 ; //as OUTPUT
PORT2 = 0b11111000 ;   // P2.0 , P2.1 & P2.1  as OUTPUT for RS , RW and EN

 

[JAMAL JIMI]

One thing more......give a delay of 20 ms before giving any command or check the busy flag..

 

[Laxman Kumar]

Problem Solved: Problem in interfacing LCD

Thanks all of u for the help...
Problem solved..
i have added
p2=0x00;
p0=0x00;
and it worked..thank u all of for the reply..

- - - Updated - - -

Thanks all of u for the help...
Problem solved..
i have added
p2=0x00;
p0=0x00;
and it worked..thank u all of for the reply..

only one question
how to print character in 2nd line..as i am using 16x2 LCD...

 

[paulfjujo]

hello,

how to print character in 2nd line..as i am using 16x2 LCD...

lcdcmd(0x80);  // 1rst line

 // to set cursor  at 2nd line  1rst caractere in X position
lcdcmd(0xC0);   
to set cursor at other X position, add X value to 0xC0 ...
lcdcmd(0xC8);  //  Y=2  x=8