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Message |
DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Strange behavior, array of char not cleaning ... |
 Posted: Thu May 15, 2008 8:47 am |
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Hi guys I was trying to empty an array that was filled in my aplication but it doesnt fills, if i put another data over it, it works but if I just try to empty not happens ...
i've tryed that way:
| Code: |
if (bReadMCard)
{
for (i=0;i<79;i++)
Track1[i] = 0x00;
for (i=0;i<40;i++)
Track2[i] = 0x00;
rMCardError = mcr_read(Track1,Track2);
bReadMCard = False;
}
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and that way to
| Code: |
if (bReadMCard)
{
for (i=0;i<79;i++)
*Track1[i] = 0x00;
for (i=0;i<40;i++)
*Track2[i] = 0x00;
//Read the card again!
rMCardError = mcr_read(Track1,Track2);
bReadMCard = False;
}
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Any tips wy this is happen ?
Thanks a lot guys,
Regards,
Diego Garcia. |
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se07860
Joined: 13 May 2008
Posts: 5
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| Posted: Thu May 15, 2008 8:52 am |
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I don't have a great experience with this compiler but i've had some problems if i tried to write the program without {} also for 1 line.
I can't do much more for you. |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 9:16 am |
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This doesn't works to :/
I've tried with the memset function to but it don't work too !
The strange thing is that if I pass another card that has both the tracks it works it fills the array with the new data, but if after that I pass another card that has just one of the tracks, the array stills with the old value on the track that doesn't exist in the card ...
Any more tips ?
Thanks a lot guys,
Regards,
Diego Garcia |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Thu May 15, 2008 9:21 am |
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The second method where you use '*' is wrong. The first method should work, but are you 100% sure the variable bReadMCard is set to TRUE?
What is the error code returned by mcr_read? |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 9:26 am |
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Yap, its true because I send the command using the usb so if I pass the other card that has both the tracks it reads ok !
I've tryed with many ways, none of then works !
I will try to shift the bits ! this should work , I hope!
Regards,
Diego Garcia |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Thu May 15, 2008 9:50 am |
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| Quote: | | Yap, its true because I send the command using the usb so if I pass the other card that has both the tracks it reads ok ! |
This doesn't convince me that the variable bReadMCard is set to TRUE. From your code fragment this can not be concluded. Have you tried setting a breakpoint after the if-statement? Or, if you don't have a debugger can you toggle a LED?
I don't understand what you mean by 'to shift the bits'. |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 10:03 am |
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ok sorry for the bad explanation ckielstra,
I know that its entering because my to my program read an card I have to send the command 0x03 from usb so when the pic receives the command it sets the var to true or else It wouldnt be reading the other data from the new card, so its reading the main problem is just that it reads the track contained in the card ok, but if the first card passed was filled with both tracks 1 and 2 and the new card just has the track 2 for example, when I send all the data to PC, the track1 is comming filled with the data from the first card ...
And shifting the bits doesnt works ...
I've just called shift the bits doing that
| Code: | int clear_tracks(char* track1, char* track2)
{
int i1, i2;
if(track1 != 0)
{
for (i1=0;i1<79;i1++)
{
while (i2<=7)
{
shift_right(Track1+i1, 1, 0);
i2++;
}
}
}
if(track2 != 0)
{
for (i1=0;i1<40;i1++)
{
while (i2<=7)
{
shift_right(Track2+i1, 1, 0);
i2++;
}
}
}
} |
Thank you very mutch for your great help guys ;)
Regards,
Diego Garcia. |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 10:26 am |
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Ok ckielstra now just to be sure I've put it an break point on it and debuged with my ICD2, and its entering ...
I dont know why is this happening ...
Any more tips ?
Thanks a lote,
Regards,
Diego Garcia |
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Ttelmah
Guest
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| Posted: Thu May 15, 2008 10:30 am |
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Well, that won't work, for so many reasons, that it rather increases my belief that Ckielstra is dead right, and your code never calls the original routine.
You test 'Track1' for being zero - remember it is the _address_ of the data now, not the data itself. It can never be zero, unless you set it to NULL. Then you never reset the i2 counter, so the shift will only ever execute on the first byte. It'll never execute at all for Track2.
Best Wishes |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 10:39 am |
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Nice Ttelmah ;) doesnt noted that i2 wasnt being reseted.
Now it works ;)
But it just works that way !
| Code: |
int clear_tracks(char* track1, char* track2)
{
int i1, i2;
if(track1 != 0)
{
for (i1=0;i1<79;i1++)
{
i2=0;
while (i2<=7)
{
bit_clear(*(Track1+i1), i2);
i2++;
}
}
}
if(track2 != 0)
{
for (i1=0;i1<40;i1++)
{
i2=0;
while (i2<=7)
{
bit_clear(*(Track2+i1), i2);
i2++;
}
}
}
}
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Thanks for the great observation ;)
Regards,
Diego Garcia |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Thu May 15, 2008 10:51 am |
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| Code: | i2=0;
while (i2<=7)
{
bit_clear(*(Track1+i1), i2);
i2++;
} |
equals:
The whole function can be reduced to: | Code: | int clear_tracks(char* track1, char* track2)
{
if(track1 != 0)
memset(track1, 0, 79);
if(track2 != 0)
memset(track2, 0, 40);
} |
Dynamic memory allocation in an embedded PIC is unlikely, so I guess track1 always points to a valid address. More likely is that you wanted to check the first byte of the array being zero? Than it should have been: |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 10:57 am |
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Ok let me try that way to see the results !
Thanks ckielstra ;)
Regards,
Diego Garcia |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 11:00 am |
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Works like a charm ;)
Thanks I had done that before but i didnt noted that the memset uses the size of the array .. :/
Thank you very mutch ckielstra and Ttelmah !
Regards,
Diego Garcia |
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DiegoGarcia
Joined: 01 Mar 2008
Posts: 48
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| Posted: Thu May 15, 2008 11:06 am |
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Now my mcr.c driver is reading in both directions track1 and 2 and working like a charm 
Thanks for your help guys ;)
Regards,
Diego Garcia |
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mpardinho
Joined: 16 Jul 2008
Posts: 8
Location: Mexico
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| mcr |
| Posted: Sun Nov 02, 2008 5:08 am |
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| your code is free(for share) ? |
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