ARM2138 need help in LCD 4 bit mode code

sorry made a mistake in copying the code

#include"lpc213x.h"
#include<stdio.h>

#define EN (1<<7)
#define RS (1<<24)

void lcd_cmd(unsigned char);
void lcd_delay(unsigned int);
void lcd_convert(char);
void lcd_data(unsigned char);
void lcd_initialise(void);
void lcd_display(void);

const unsigned char cmd[4] = {0x28,0x0c,0x06,0x01};
unsigned char msg[] = {">PS-Primer 2148<"};
unsigned char msg1[]= {":: LCD Demo! ::"};

int main()
{ PINSEL2 = 0; PINSEL0 = 0; IODIR0 = 0x00000078; IODIR1 = 0x01000000; lcd_initialise(); lcd_display(); return 0;
}

void lcd_initialise(void)
{

int i=0; lcd_convert(0x30); lcd_delay(16); lcd_convert(0x30); lcd_delay(16); lcd_convert(0x30); lcd_delay(16); lcd_convert(0x20); lcd_delay(16);

for(i=0;i<4;i++) { IOCLR0 = 0xF << 3; lcd_cmd(cmd[i]); lcd_delay(15);

}

}

void lcd_cmd(unsigned char data)
{ IOCLR1 |= RS; //RS
lcd_convert(data);
}

void lcd_delay(unsigned int n) { unsigned int i,j; for(i=0;i<n;i++) for(j=0;j<12000;j++); }

void lcd_display (void)
{ int i=0,j=0; /* first line message */ lcd_cmd(0x80); lcd_delay(15);

while(msg[i]!='\0')

{ lcd_delay(15); lcd_data(msg[i]); i++; }

lcd_delay(15); /* second line message */ lcd_cmd(0xc0); lcd_delay(15);

while(msg1[j]!='\0')

{ lcd_delay(5); lcd_data(msg1[j]); j++; }

lcd_delay(15);
}

void lcd_convert(char c) {

if(c & 0x08) IOSET0 = 1 << 3; else IOCLR0 = 1 << 3; if(c & 0x04) IOSET0 = 1 << 4; else IOCLR0 = 1 << 4; if(c & 0x02) IOSET0 = 1 << 5; else IOCLR0 = 1 << 5; if(c & 0x01) IOSET0 = 1 << 6; else IOCLR0 = 1 << 6;

IOSET0 = EN; lcd_delay(15); IOCLR0 = EN; lcd_delay(15);

if(c & 0x80) IOSET0 = 1 << 3; else IOCLR0 = 1 << 3; if(c & 0x40) IOSET0 = 1 << 4; else IOCLR0 = 1 << 4; if(c & 0x20) IOSET0 = 1 << 5; else IOCLR0 = 1 << 5; if(c & 0x10) IOSET0 = 1 << 6; else IOCLR0 = 1 << 6;

IOSET0 = EN; lcd_delay(15); IOCLR0 = EN; lcd_delay(15);

}

void lcd_data (unsigned char data) { IOSET1 |= RS; //0x1000; //RS // IOSET1 |= RS; // IOCLR0 |= RW; //0x2000; //RW lcd_convert(data); }

You know if you read the posting instructions you'd have used the PRE tags for source code..

Suggest you evaluate the actual delay created by your delay function, check that it generates enough delay compared to the documentation for your LCD, consider using volatile variables here so the optimizer doesn't eliminate the code.

Thanks a lot. i am new to coding of ARM processors i'll try and change the delay function, maybe a timer will work. i referred to a code on the web and there the delay function was written using a for loop so i thought its a easier way of writing a delay function.

The web is full of for loop delays, because beginners always thinks they are the easiest way. And they - when they work, which they quite often doesn't. The language standard or the chip manufacturer or the compiler vendor does not have any paragraph where they claim that they guarantee a for loop delay to give any expected delay time. But lots of people feel fine to program making huge assumptions with trial-and-error designs.

So in the end - the most common solution you find on the net need not be the best. Or even good. Especially since the majority of code available on the net has been published by beginners - not too many professional developers spends any time posting what they consider trivial code.

thank you :)