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not able to write to LCD - C program included

Hello there I am trying to display a message on the lcd of this custom designed Microcontroller kit (www.nskelectronics.in/.../8051_project_board.pdf) using P89V51RD2N. I have tried to burn the following program but it just doesn't work.Can someone help me with this ..where am I going wrong.??....

#include <REG51.H>
char check = 0x80;
sbit EN = P3^4 ;
sbit RS = P3^5;
//sbit RW = ;        //not mentioned on the schematic

void delay();
unsigned char array[3];
sfr dat = 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()
{
        dat = 0x38;
        cmd();
        dat = 0x01;
        cmd();
        dat = 0x0c;
        cmd();
        dat = 0x86;
        cmd();

        dat = 0xdf;
        write_lcd();

        dat = 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();
}

Also I would like to know the purpose of the startup code in a Keil project...Is it obligatory to use the startup code?.

Thanks

Parents

0 sinkeil kool over 14 years ago in reply to erik malund

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;
        }

Reply

0 sinkeil kool over 14 years ago in reply to erik malund

#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;
        }

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