Issue with Interfacing LCD with PIC16F877A

[Farhaad]

I would like to know why after E is printed in the 2nd line completely, after some time why it starts to print on first line too.
Simulation: Ive used the Proteus Version 8.16
Compiler: CCS Compiler 5.008
P.S Im a new joiner to this forum. So if there are any mistakes, please let me know. Ill try to follow the rules next time

 

[Ian Rogers]

LCD's are quite easy to use.
Here is my entire program.. go though and you will see.

#include <xc.h>

#pragma config FOSC=HS
#pragma config WDTE=OFF
#pragma config BOREN=OFF

char txt[] = {"hello world from the other side of mars"};

void delayUs(int x)
    {
    while(x--);
    }

void delayMs(int x)
    {
    while(x--)
        delayUs(1000);
    }

void    LCDcmd(char cmd)
    {
    PORTB = cmd;
    RC1 = 0;
    RC0 = 1;
    RC0 = 0;
    delayMs(5);
    }

void    LCDdata(char dat)
    {
    PORTB = dat;
    RC1 = 1;
    RC0 = 1;
    RC0 = 0;
    RC1 = 0;
    delayMs(5);
    }

void LCDgoto( char col, char row)
    {
    unsigned char tmp = 0x80;
    if(row) tmp+=0x40;
    tmp+= col;
    LCDcmd(tmp);
    }

void LCDstring(char * str)
    {
    while(*str !=0)
        LCDdata(*str++);    
    }

void LCDinit(void)
    {
    TRISB = 0;
    TRISC = 0;
    delayMs(40);
    PORTB = 0x30;
    RC0 = 1;
    RC0 = 0;
    delayMs(15);
    PORTB = 0x30;
    RC0 = 1;
    RC0 = 0;    
    delayMs(5);
    PORTB = 0x30;
    RC0 = 1;
    RC0 = 0;
    LCDcmd(0x38);
    LCDcmd(0xD);
    LCDcmd(6);
    LCDcmd(1);
    }

void main(void)
    {
    LCDinit();
    LCDstring(txt);
    while (1)
        {
        LCDcmd(0x18);
        delayMs(300);
        }
 }

 

[Farhaad]

It's probably hex 0x40 then

I have a question. If I simply run the loop It stores 40 Hex Characters and the 41st Hex Character is printed on the 2nd Line. But If I try to view all the characters by starting to display the characters from First Row Last Column position(0x8F) then I can see only Hex Characters. From 'Space' to '8'. Why?

 

[Farhaad]

LCD's are quite easy to use.
Here is my entire program.. go though and you will see.

#include <xc.h>

#pragma config FOSC=HS
#pragma config WDTE=OFF
#pragma config BOREN=OFF

char txt[] = {"hello world from the other side of mars"};

void delayUs(int x)
    {
    while(x--);
    }

void delayMs(int x)
    {
    while(x--)
        delayUs(1000);
    }

void    LCDcmd(char cmd)
    {
    PORTB = cmd;
    RC1 = 0;
    RC0 = 1;
    RC0 = 0;
    delayMs(5);
    }

void    LCDdata(char dat)
    {
    PORTB = dat;
    RC1 = 1;
    RC0 = 1;
    RC0 = 0;
    RC1 = 0;
    delayMs(5);
    }

void LCDgoto( char col, char row)
    {
    unsigned char tmp = 0x80;
    if(row) tmp+=0x40;
    tmp+= col;
    LCDcmd(tmp);
    }

void LCDstring(char * str)
    {
    while(*str !=0)
        LCDdata(*str++);   
    }

void LCDinit(void)
    {
    TRISB = 0;
    TRISC = 0;
    delayMs(40);
    PORTB = 0x30;
    RC0 = 1;
    RC0 = 0;
    delayMs(15);
    PORTB = 0x30;
    RC0 = 1;
    RC0 = 0;   
    delayMs(5);
    PORTB = 0x30;
    RC0 = 1;
    RC0 = 0;
    LCDcmd(0x38);
    LCDcmd(0xD);
    LCDcmd(6);
    LCDcmd(1);
    }

void main(void)
    {
    LCDinit();
    LCDstring(txt);
    while (1)
        {
        LCDcmd(0x18);
        delayMs(300);
        }
 }

Your using MPLAB right? Oh god. I never used MPLAB much, so the port syntax and stuff is difficult for me to understand. But I'll try.