Hi all,

I am having problem with the following code. This code takes frequency from user and converts the ascii value recieved through serial port into decimal.
Problem:-> When I input a frequency between 40000 and 70000 it never enters the first condition.
Here is what happens:
works perfectly fine for frequency<40000 and above 99000 (it goes into the condition where it should go) but, goes into condition 2nd (>11000 and <40000) for input frequency (>76000 and <99000) and goes in last condtion (else ) for input frequency (>40000 and < =76000).

#include <stdio.h>

#include <REGX52.h>

void frequency_calc ( unsigned char a1,unsigned char b1,unsigned char c1,unsigned char d1,unsigned char e1,unsigned char f1);
char uart_data ;
sfr p1 = 0x90;
sfr p2 = 0xA0;
sfr p0 = 0x80;
sfr p3 = 0xB0;
sbit led1=P1^0;
sbit led2=P1^1;
sbit led3=P1^2;
sbit led4=P1^3;
sbit led5=P1^4;
sbit led6=P1^5;
sbit led7=P1^6;
sbit led8=P1^7;
sbit led0_0=P0^0;
sbit led0_1=P0^1;
sbit led0_2=P0^2;
sbit led0_3=P0^3;
sbit led0_4=P0^4;
sbit led0_5=P0^5;




int i=1,res_reset=70,res_set=70;

unsigned char a=0x00;
unsigned char b=0x00;
unsigned char c=0x00;
unsigned char d=0x00;
unsigned char e=0x00;
unsigned char f=0x00;
unsigned char g=0x00;



/**
* FUNCTION_PURPOSE: This file set up uart in mode 1 (8 bits uart) with
* timer 1 in mode 2 (8 bits auto reload timer).
* FUNCTION_INPUTS: void
* FUNCTION_OUTPUTS: void
*/
void main (void)
{
SCON = 0x50; /* uart in mode 1 (8 bit), REN=1 */
TMOD = TMOD | 0x20 ; /* Timer 1 in mode 2 */
TH1 = 0xFD; /* 9600 Bds at 11.059MHz */
TL1 = 0xFD; /* 9600 Bds at 11.059MHz */
ES = 1; /* Enable serial interrupt*/
EA = 1; /* Enable global interrupt */
TR1 = 1; /* Timer 1 run */

while(1); /* endless */
}


void frequency_calc ( unsigned char a1,unsigned char b1,unsigned char c1,unsigned char d1,unsigned char e1,unsigned char f1)
{

int a_dec=0,b_dec=0,c_dec=0,d_dec=0,e_dec=0,f_dec=0,temp=0,temp1=0,res_set=70,res1_set=70;
int double_transitions=0,double_transitions1=0;
unsigned long frequency=0;
led2=1; /*/this is used for x9315 up/down' ...led2=1 means count up */
p0=0xff;
p2=0x00;

while (a1 != 0x00)
{
a1=a1-0x01;
a_dec=a_dec+1; }



while (b1 != 0x00)
{
b1=b1-0x01;
b_dec=b_dec+1; }


while (c1 != 0x00)
{
c1=c1-0x01;
c_dec=c_dec+1; }


while (d1 != 0x00)
{
d1=d1-0x01;
d_dec=d_dec+1; }

while (e1 != 0x00)
{
e1=e1-0x01;
e_dec=e_dec+1; }



while (f1 != 0x00)
{
f1=f1-0x01;
f_dec=f_dec+1; }

frequency= (a_dec * 100000) +(b_dec*10000) + (c_dec*1000)+(d_dec*100)+(e_dec*10)+(f_dec);

//*******************condition 1*****************************
if (frequency>=40000 && frequency<=70000) //condition 1
led0_0=!led0_0 ;

//*******************condition 2*****************************
else if (frequency>=99000 && frequency<=120000) //condition 2

led0_1=! led0_1;


//*******************condition 3*****************************
else if ( frequency>=11000 && frequency <=70000) //condition 3

{

double_transitions = 2* ((4.548e5/frequency) -9);
p2=p2+0x01;
while (double_transitions != 0)
{
double_transitions=double_transitions - 1;
led4=!led4;
}

}
//*******************condition 4*****************************
else //condtion4
{
double_transitions = 2* ((4.548e6/frequency) -37);
led0_2=!led0_2;
while(res1_set!=0)
{
led4=!led4;
res1_set= res1_set-1;
}

}




}

void serial_IT(void) interrupt 4
{
if (RI == 1)
{
/* if reception occur */
//i++;
RI = 0;
/* clear reception flag for next rec eption */

uart_data = (SBUF - 0x30); /* Read receive data */
if (i==1)
{a= (SBUF - 0x30);}
else if (i==2)
{b= (SBUF - 0x30);}
else if (i==3)
{c= (SBUF - 0x30); }
else if (i==4)
{d= (SBUF - 0x30); }
else if (i==5)
{e= (SBUF - 0x30); }
else if (i==6)
{f= (SBUF - 0x30); }




i++;
if (i==7)
{
i=1;
res_reset=70;
while(res_reset!=0)
{ led2=0;
led4=!led4;
led5=!led5;
led6=!led6;
led7=!led7;
res_reset= res_reset-1;

}
frequency_calc ( a, b, c, d, e, f);
}


SBUF = uart_data ; /* Send back same data on uart*/

}
else
TI = 0;
}
/* if emission occur */
/* clear emission flag for next emission*/

Thanks for any help