[51] problem in Generating random nmber using rand() function in embedded c

[MANO.5]

i modified the example random number generation program from keil help section.
keil example program

#include <stdlib.h>
#include <stdio.h> /* for printf */

void tst_rand (void) {
  int i;
  int r;

  for (i = 0; i < 10; i++) {
    printf ("I = %d, RAND = %d\n", i, rand ());
  }
}

my program was

 #include<reg51.h>
 #include <stdlib.h>
 sfr lcd_data_pin=0xA0;//p2 port
sbit rs=P1^0;
sbit rw=P1^1;
sbit e=P1^2;
void delay(unsigned int count)    //Function to provide delay
{
    int i,j;
    for(i=0;i<count;i++)
    for(j=0;j<1275;j++);
}
void lcd_cmd(unsigned char value)
{
	lcd_data_pin = value;
	rs=0;
	rw=0;
	e=1;
	delay(1);
	e=0;
	delay(1);
}
void lcd_data(unsigned char value)
{
	lcd_data_pin =value;
	rs=1;
	rw=0;
	e=1;
	delay(1);
	e=0;
	delay(1);
}
void lcd_init()
{	
         lcd_cmd(0x38);
	lcd_cmd(0x0e);
	lcd_cmd(0x01);	
	lcd_cmd(0x80);
}
void lcd_string(unsigned char *disp)	 //LCD string function 
{
	char x;
	for(x=0;disp[x]!=0;x++)
	{
		lcd_data(disp[x]);
	}

}

  void lcd_data_int(int time_val)		//  to send three digit number
{
	int int_amt;
    int_amt = time_val/1000;
	lcd_data(int_amt+48);
	time_val = time_val%1000;
	int_amt = time_val/100;
	lcd_data(int_amt+48);
	time_val = time_val%100;
	int_amt = time_val/10;
	lcd_data(int_amt+48);
	int_amt = time_val%10;	
	lcd_data(int_amt+48);
}

void tst_rand (void) {
  unsigned int i;	  

  i= rand();
 lcd_cmd(0x80);
lcd_string("number: ");
delay(250);

lcd_cmd(0xc0);
 lcd_data_int(i);
 
 
}
void main()
{
lcd_init();
  while(1)
   {
   	  tst_rand ();
   }   

}

when i compile this code it gives 3 warnings and when simulate in proteus it was blinking...no output

this is the 3 warnings from keil

Rebuild target 'Target 1'
compiling rand.c...
linking...
*** WARNING L7: MODULE NAME NOT UNIQUE
MODULE: G:\PROGRAM FILES\KEIL\C51\LIB\C51S.LIB (RAND)
*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL
SYMBOL: RAND
MODULE: rand.obj (RAND)
*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL
SYMBOL: RAND
MODULE: rand.obj (RAND)
ADDRESS: 0129H
Program Size: data=15.0 xdata=0 code=461
creating hex file from "rand"...
"rand" - 0 Error(s), 3 Warning(s).

So help me to solve this issue

 

[horace1]

try

#include <stdlib.h>     /* srand, rand */

have you thought how you would seed the generator - it is only pseudo-random so unless you seed differently each time you run you will get the same sequence of numbers

 

[MANO.5]

Hello horace1,
ya it's pseudo-random .But i want to know what is this error & how to solve this

 

[horace1]

Hello horace1,
ya it's pseudo-random .But i want to know what is this error & how to solve this

it looks like a problem with the Keil compiler
could be worth putting a post on the Keil forum?
https://www.keil.com/forum/5229/
https://www.keil.com/support/man/docs/bl51/bl51_l1.htm

 

[MANO.5]

thank you horace1,
I am tried in keil also.But waiting for answers.. here also looking forward.pls anybody compile and post the result to know there is problem in my keil installation..

 

[horace1]

it could be worth reinstalling the compiler

 

[MANO.5]

on different pc it was compiled without any error or warnings.But no output in lcd..so please somebody check is there any mistakes in program...........

 

[embpic]

as u are using rand function but whenever u feed same value it will return same output. so u have to feed different value as input so u will get really random numbers.

 

[MANO.5]

When i was simulating this program in proteus it didn't displaying anything...giving same number is not problem ..the problem is not displaying anything.....