weird behaviour of ex_fat.c example - help appreciated :)

[xa4]

Greetings !

I used the provided ex_fat.c example and changed a few parameters in order to fit to my configuration:

#include <18F8722.h> (my pic)

#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)
(but I tested also with the default line and there are no changes)

#use delay(clock=10000000) (my oscillator on the circuit board)



It compiles without problem with PCWH compiler v4.062
The PIC is programmed without problem using MPLAB 7.6

When I open the terminal window, I see no > sign that should appear.
Each character that I type in the hyperterminal window is sent back (rs232 is working)

But when I try to send valid commands like help[return] nothing happens.

I tried to put some putc('x'); in several places but it is never displayed.
I tried to put some printf("hello"); at the beginning of the main() method but it doesn't show up in the hyperterm window...

I'm a bit lost and I don't understand what is wrong..

Could somebody provide me with some help ? I would be very grateful.


Thank you very much and best regards,
X. Righetti

[crystal_lattice]

is your crystal running?? your terminal might have a setting to echo each char sent so your rs232 could not be working after all, rather flash a led...

[xa4]

Dear crystal_lattice, thank's for your prompt answer !

Yes, the crystal is running for sure (and the frequency is correct).. also, I commented the line in the example where characters are echoed back and and they are not echoed anymore.. So this is not the problem...

Thank's anyway...... any other ideas ?


X. Righetti

[crystal_lattice]

How do you send the [return], my terminal program needs the $0d sign appended eg. dir$0d maybe yours needs something aswell? I've tried the ex_fat in the past but ran into other problems - files did not update... so am busy with other fat lib..

[xa4]

Dear crystal_lattice,

I think the return carriage character is well understood as it is the only character that isn't echoed back (as specified in the code.. so it is recognized).

But this is not the source of the problem as I can't even write something with printf() nor with putc() as I wrote in my first post..

So you are using other fat libs ? Maybe you could provide with another working example ?

Thank's!

[Indy]

[xa4]

Dear Indy,

I don't know what happened, I rebooted my computer and everything (almost) works like a charm !!

I could create files and dirs but I couldn't write to the files or access the dirs.. so I used the format function from the hyperterm to format it. For the moment I tried the values 2^16 and 2^17 ie. I typed "format 65536" and "format 131072" (It is a 1gig microSD) and now I can access the dirs, append and read the files !!! Everything works great !! But....

But when I put it into my computer, I see nothing at all.. And when I format it from my computer (fat16) and I put it back into my circuit, it can still see the dirs and files I created earlier.. Idem if I put some file/folder on the SD card from my PC, I can't see them in the hyperterm window.

So I have one card, but it seams like I have two partition.. one that is seen by the computer, and one that is seen by my cicruit board.. and they are completely independent !!

Does somebody have a solution to see on my PC the files that have been created by the PIC ? (hopefully an easier solution than writing an application to download the content of the card via rs232 and save it to the computer)


Anyway, thank's a lot for your advices, I will download now the latest version of mplab and the terminal application you suggested..


here is the listing of my code, for reference:

code removed due to copyright issues...... sorry

[ckielstra]

[xa4]

Dear ckielstra,

I removed the code.. sorry about that..

Is it possible to store the files (or format the card) in such a way that I don't need to use apps like WINHEX or DISKEDIT to view the content of the SD/MMC ?

thank's

[Indy]

[Indy]

[Indy]

I just see the CCS code defaults to FAT32 but I remember reading somewhere the FAT16 is more stable. In FAT.c change to FAT16:

[xa4]

[Indy]

I remember reading one of the two file systems was better tested. I thought this was FAT16 but you found the original text and it turns out I was wrong and FAT32 is the one being better tested.

I never used a FAT system on the PIC processor so can't point you to a good working library. Try searching this forum.

[asmallri]