aydi
Joined: 11 Aug 2010
Posts: 12
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| PB to decode frame |
 Posted: Thu Aug 12, 2010 6:14 am |
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hello,
I use this elements to develop my program.
PIC :18F2550
compiler: PICC
simulator:ISIS
I develop a program to decode a frame sent through the port rs232.
Format of the frame: @0AX,Fx,Y,Fy,Z1,Fz1,Z2,Fz2
I want to decode this frame and to have the value of each element lonly
X=...
Y=....
Fx=....
.
.
This program it just give me the first element which is the value of X.
And the other values is empty. I didn't know why it works very well for X and not for the others elements.
For example: I write like that @0A 34,67,89,90,45,34,56,34
The result:
X=34
Fx=
Y=
Fy=
.
.
Thanks in advance.
The PROGRAM:
| Code: |
#include <18F2550.h>
#include <string.h>
#fuses HS,NOWDT,NOPROTECT,PLL5,CPUDIV1
#use delay(clock=20000000)//Xtal frequency = 20MHz
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
void wait() //Subroutine to wait for 2ms or until a character is received
{
int countdown;
countdown=200;//Charge value to 200 times 10us
while((--countdown!=0)&&!kbhit()) //kbhit returns true when rs232 receives a character
delay_us(10);
}
void main()
{
char chaine[35], X[35], Y[35], Z1[35], Z2[35], Fx[35], Fy[35], Fz1[35], Fz2[35], chaine1[35];
int i=0,cmpt=0;
//Do a loop
while(true)
{
wait();//Wait for visualization or another character
if(kbhit())
{
gets(chaine);
WHILE(chaine[i]!='\0')
{
chaine[i]=chaine[i+3];
if (chaine[i]==',')
cmpt=cmpt+1;
switch(cmpt)
{
case 0:X[i]=chaine[i];break;
case 1:Fx[i]=chaine[i];break;
case 2:Y[i]=chaine[i];break;
case 3:Fy[i]=chaine[i];break;
case 4:Z1[i]=chaine[i];break;
case 5:Fz1[i]=chaine[i];break;
case 6:Z2[i]=chaine[i];break;
case 7:Fz2[i]=chaine[i];break;
default: break;
}
i++;
}
printf("\r\n");
printf("chaine_caractere=%s",chaine);
printf("\r\n");
printf("cmpt=%d",cmpt);
printf("\r\n");
printf("X=%s",X);
printf("\r\n");
printf("Fx=%s",Fx);
printf("\r\n");
printf("Y=%s",Y);
printf("\r\n");
printf("Fy=%s",Fy);
printf("\r\n");
printf("Z1=%s",Z1);
printf("\r\n");
printf("Fz1=%s",Fz1);
printf("\r\n");
printf("Z2=%s",Z2);
printf("\r\n");
printf("Fz2=%s",Fz2);
}
}
} |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Thu Aug 12, 2010 6:47 am |
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I don't know ISIS, but debugging software requires you to use the right tools. For example in the free MPLAB toolsuite there is a Simulator which allows you to step through your program and examine the value of variables at each state.
In your program it goes well for x:
x[0] = chaine[0] // space
x[1] = chaine[1] // 3
x[2] = chaine[2] // 4
y[3] = chaine[3] // , <-- Here it goes wrong, you should write to Y[0] and you want to skip the '.'
I recommend you to study the standard C function strtok() which was designed for the purpose of extracting parameters from a string. It is not the most easy function to understand but many examples can be found on the internet. |
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