atof not working in LPC 1788

I am writing Programm using LPC1788, with RTX os .
Through out Programm i have used atof function many times, but now if m adding new atof function, it is not working Properly, even i dont get any error while compilation or debugging.

Alo if i am adding manual calculation for float copnversion , still same issue occured , converted float value is incorrect.

i got converted float value is incorrect why such issue occured , i didnt get it..

currently my stack size 0x0000 1000

and heap size : 0x0000 0500

and OS stack size: 500

someone plz help me out.

/**************************************************
Function: calculate_float_value
Comment: This use to return a float value for buffer like "000.00".
Arguments: The buffer name & the no of digit in the buffer including decimal point
Returns: The absolute decimal point value.
***************************************************/
float calculate_float_value(char* temp_buff,uint8_t num_digit)
{ uint8_t i; uint32_t return_value,temp; //temp used only when it is 7-digit. uint32_t deci_point; float result; char store_value[10];

for(i=0;i<num_digit;i++) { store_value[i] = *temp_buff++; }

if(num_digit==5) { return_value = ( ( ((store_value[0] & 0x0f)*1000) + ((store_value[2] & 0x0f)*100) +((store_value[3] & 0x0f)*10)+ (store_value[4] & 0x0f) )/1000); deci_point = ( ( ((store_value[0] & 0x0f)*1000) + ((store_value[2] & 0x0f)*100) +((store_value[3] & 0x0f)*10)+ (store_value[4] & 0x0f) )%1000);

result = (float)return_value + ((float)deci_point/1000);

}

if(num_digit==6) { return_value = 0; return_value = (store_value[0] & 0x0f); return_value *= 10000; return_value += ((store_value[1] & 0x0f)*1000); return_value += ((store_value[3] & 0x0f)*100); return_value += ((store_value[4] & 0x0f)*10); return_value += (store_value[5] & 0x0f);

deci_point = return_value; return_value /= 1000; deci_point %= 1000;

result = (float)return_value + ((float)deci_point/1000); }

if(num_digit==7) { return_value = 0; return_value = ((store_value[0] & 0x0f)*100)+((store_value[1] & 0x0f)*10)+((store_value[2] & 0x0f)*0x0f); deci_point = ((store_value[4] & 0x0f)*100) +((store_value[5] & 0x0f)*10) +(store_value[6] & 0x0f);

result = (float)return_value + ((float)deci_point/1000); }

if(num_digit==8) { return_value = 0; return_value = ((store_value[0] & 0x0f)*1000)+((store_value[1] & 0x0f)*100)+((store_value[2] & 0x0f)*10)+(store_value[3] & 0x0f); deci_point = ((store_value[5] & 0x0f)*100) +((store_value[6] & 0x0f)*10) +(store_value[7] & 0x0f);

result = (float)return_value + ((float)deci_point/1000); }

return((float)result);
} /************************************************************/