not able to write to LCD - C program included

1) You haven't told us what you expected to happen.

2) You haven't told us what actually happened.

3) Isn't it a bit boring with a main loop that doesn't do anything but constantly try to initialize the display()?

4) Have you found many web sites recommending for loops to create delays? How do you guarantee that the loop produces the delay you expect it to?

5) You are using a number of magic values - why not give these values a name?

6) Your only comments are
//sbit RW = ; //not mentioned on the schematic
and
//data lines are connected to LCD from port P1 - as per the circuit

That isn't exactly a well-documented program. You can't even say that it is self-documenting, with variable names like "array", "check" and "dat".

1) You haven't told us what you expected to happen.

2) You haven't told us what actually happened.

3) Isn't it a bit boring with a main loop that doesn't do anything but constantly try to initialize the display()?

4) Have you found many web sites recommending for loops to create delays? How do you guarantee that the loop produces the delay you expect it to?

5) You are using a number of magic values - why not give these values a name?

6) Your only comments are
//sbit RW = ; //not mentioned on the schematic
and
//data lines are connected to LCD from port P1 - as per the circuit

That isn't exactly a well-documented program. You can't even say that it is self-documenting, with variable names like "array", "check" and "dat".

That isn't exactly a well-documented program. You can't even say that it is self-documenting, with variable names like "array", "check" and "dat".
I know of no one that can say "that it is self-documenting", but know of many that claim so.

Erik

Please note I have posted the latest post since I had not mentioned about the LCD make in the older post

Ok my apologies ....I am a newbie hope you can forgive me for that ...

I am just trying to display a character on the LCD ...Just want to get started by sending a character first and then I would like to get complete understanding about scrolling,displaying various chars on different rows etc...

I have mentioned the link of the project board schematic ..hence the reason for just 2-3 comments.Please take a look at the schematic since I wasn't confident about the RW pin connections for the LCD

Sorry about the programming style I was frustrated about trying this and hence was just trying to get a basic code working on the board

Thanks for the comments will certainly improve.

here is the modified version of the code

//Please note the LCD used in this board is JHD162A

#include <REG51.H>

sbit EN = P3^4 ;
sbit RS = P3^5;
//sbit RW = ;        //not mentioned on the schematic

void delay();
sfr P1_data = 0x90;           //data lines are connected to LCD from port P1 - as per the circuit
void delay(void);

void cmd()
{
        RS = 0;
        //RW = 0;
        EN = 1;
        EN = 0;
        delay();
}

void write_lcd()
{
        RS = 1;
        //RW = 0;
        EN = 1;
        EN = 0;
        delay();
}

void init_lcd()
{
        P1_data = 0x38;
        cmd();
        P1_data = 0x01;
        cmd();
        P1_data = 0x0c;
        cmd();
        P1_data = 0x86;
        cmd();

        P1_data = 0xdf;
        write_lcd();

        P1_data = 0x51 ;
        write_lcd();

}

void delay()
{
        int i,j;
        for(i = 0; i< 75 ; i++)
                for(j = 0; j < 75 ; j++);
}


void main()
{
        for(;;)
        init_lcd();
}

hence the reason for just 2-3 comments.how about excuse

do you actually think we sit around having nothing better to do than to try to figure out your scribbles?. We are all willing to take a few minutes away from your paid activities, but do not have "figuring out scribbles" time.

additionally the amazing thing is that with good variable names and good comments, you may actually figure it out yourself

Erik

from your paid activities
should, of course be

from our paid activities

Hello Erik ..sorry if you haven't figured the issue since the comments I provided are of little help .... As per the schematic I have not assigned any value to the variable RW( read / write ) command value variable.The LCD isn't grounded on the PCB too hence I had to mention the link to make sure that you get where exactly the READ/WRITE pin from LCD goes ..its just left out ..and just to mention I am not paid ..still jobless trying my best to learn and move on ...Please let me know where I am going wrong..thanks

its ok a small typo but definitely describes the hectic pressure you would be under ...

its ok a small typo but definitely describes the hectic pressure you would be under
I am not under "hectic pressure" but the people that pay me for working would not appreciate if I took time out to figure out your scribbles

This is my last post in this thread, your whines "please check my scribbles" do not affect me.

Erik

Ok Erik seems you are disappointed with the way I presented the issue here.I have coded another one this time with proper comments and even this doesn't seem to show anything on the LCD screen...the LCD is glowing but nothing is shown up

#include <reg51.h>
#include <stdio.h>
#include <intrins.h>

//ANSI STYLE PROTOTYPE
void lcddata( unsigned char value);
void lcdcmd( unsigned char value);
void Delay( unsigned int itime );

//SFR names declarations
sfr lcd_port = 0x90;
sbit RS = P3^5;
sbit EN = P3^4;
//sbit RW = //not used since schematic doesn't show the pin connecting anywhere


void main(void)
{
        unsigned int i,k = 0;              //Delay variable
        unsigned char l[10] = {0x38,0x0E,0x06,0x01,0x41};
        //unsigned char l[10] = {0x38,0x01,0x80};
        char str[] = "Helloworld";
        char str1[] = "welcome";
        char *p;                                        //pointer declarations


        for(i = 0 ;i< 3 ; i++)
        lcdcmd(l[i]);           //sending basic LCD commands to LCD

        for( p = str; *p ;p++)
        lcddata(*p);

        lcdcmd(0xC0);   //0xC0 command for displaying on second line

        for( p = str1; *p ;p++)
        lcddata(*p);


        do{                                     //infinite loop for LCD scrolling
                lcdcmd(0x18);                   //0x18 command for LCD scrolling
                Delay(50);
        }while(1);
}


        void Delay( unsigned int itime)
        {
                int i,j;
                for( i = 0; i < itime ;i++)
                        for( j = 0; j < 1275; j++);
        }

        void lcdcmd( unsigned char value )
        {
                  lcd_port = value;
                  RS = 0;               //register select = 0 for command mode
                  EN = 1;               //latch enable = HIGH
                  _nop_();
                  EN = 0;               //latch enable = LOW
                  Delay(10);
                  return;
        }

        void lcddata( unsigned char value )
        {
                  lcd_port = value;
                  RS = 1;               //register select = 1 for data register
                  EN = 1;               //latch enable = HIGH
                  _nop_();
                  EN = 0;               //latch enable = LOW
                  Delay(10);
                  return;
        }