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riz179
Joined: 06 Apr 2012
Posts: 21
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| ATOF() function error |
 Posted: Sat Apr 07, 2012 4:54 am |
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Hey! please help,
I'm using 4.057 and the problem is the atof() function is not displaying any data it just shows 0.00 |
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dyeatman
Joined: 06 Sep 2003
Posts: 1923
Location: Norman, OK
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| Posted: Sat Apr 07, 2012 5:15 am |
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It would be helpful for you to show us the lines in your code where it is
used. Also show us the variable declarations.
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SherpaDoug
Joined: 07 Sep 2003
Posts: 1640
Location: Cape Cod Mass USA
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| Posted: Sat Apr 07, 2012 5:38 am |
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We need to know exactly what type and value you are passing to atof() and exactly how you are determining what the output is. A short compilable example program is usually best.
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riz179
Joined: 06 Apr 2012
Posts: 21
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| Posted: Sun Apr 08, 2012 7:48 am |
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Thanks for quick reply,
I have checked the atof() its doing well but the problem is actually my string don't get the value and remains empty, although there is no error. Below I'm posting the lines in which I am putting values in string. key and key[i] both are defined char and global, but the key[i] remains null.
| Code: |
#ifdef(__PCH__)
#include <pic18f452>
#DEVICE ADC=10
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#endif
#define use_portb_kbd TRUE
#include <kbd.c>
#include <stdio.h>
#include <stdlib.h>
#include <lcd.c>
void keypad(void);
unsigned char adcchk=1;
char key;
char key1[100];
unsigned long adc;
float volts,presr,x ;
void main()
{
lcd_init();
kbd_init();
SET_TRIS_B(0xff);
port_b_pullups(true);
keypad();
lcd_putc("\f L");
delay_ms(300);
printf(lcd_putc,"\f %s",key);
x = atof(key1);
printf(lcd_putc,"%f",x);
}
void keypad(void)
{
int i=0;
while (true) {
key=kbd_getc();
if(key!=0)
if(key=='*')
{
lcd_putc('\f');
break;
}
else
{ if(key=='#')
{ lcd_putc('.');
}
else
{ lcd_putc(key);
}
key1[i]=key;
}
i++;
}
} |
Last edited by riz179 on Sun Apr 08, 2012 9:20 am; edited 1 time in total |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19328
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| Posted: Sun Apr 08, 2012 9:07 am |
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Several things that might/do apply:
Show the declaration of 'key'. Is space actually being allocated by your declaration.
Remember a 'string' (which is what atof wants), needs to be _null terminated_. Nothing in this code is doing this....
Tidy your layout. makes it much easier to read.
Think about 'limits'. What happens if somebody keeps on typing?.
Remember the string for atof, needs the decimal point, as well as the display.
| Code: |
void keypad(void) {
int i=0;
while (i<MAXINPUTLEN) {
key=kbd_getc();
if(key!=0) {
if(key=='*') {
lcd_putc('\f');
key[i]='\0'; //terminate the string
return; //and exit
}
if(key=='#') {
lcd_putc('.');
key[i++]='.'; //string needs decimal point as well
}
else {
lcd_putc(key);
key[i++]=key;
}
}
}
key[i-1]='\0'; //terminate the overlength string
}
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Assuming 'MAXINPUTLEN', is defines as the maximum size of the string.
Can your kbd_getc, actually return a null character?. If not, the first test is pointless. If it can, what does this mean?. Timeout?. If so, you should exit tidily, rather than just keeping looping.
Best Wishes |
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riz179
Joined: 06 Apr 2012
Posts: 21
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| Posted: Sun Apr 08, 2012 12:47 pm |
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@Ttelmah..,,
thanks man, got it working... |
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