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CCS MMCSD & FAT32 Drivers on SD - Working for anyone? |
Posted: Mon Oct 13, 2008 10:12 pm |
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I only want to hear from people with success using the included ex_fat.c with the mmcsd.c and fat.c (in FAT32 mode).
It's not working for me.
Thanks,
-Ben |
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bkamen
Joined: 07 Jan 2004 Posts: 1615 Location: Central Illinois, USA
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Posted: Mon Oct 13, 2008 10:14 pm |
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Gah! I thought I was logged in and it let me post.
Funky. -- anyway - let me know.
I forgot to add, I'm using CCS latest version under MPLAB 8.10 w/HPC Explorer and PICtail. (yes, I've already matched up the right #defines for the SPI lines and nCS as well as disconnected the LM74 temp sensor and it's pullup resistors on the HPC PCB)
I've been doing this with SanDisk 512MB, 1G cards.
I've had to make all sorts of additions to get even a heartbeat.. (like a correct init procedure)
The straight stock code inits, and directories don't lock up... but anything else
starts and then freezes the PIC.
I've been able to at least make it not freeze, but nothing works (init_fat and print_CID and print_CSD are sporadic at best)
Thanks,
-Ben |
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asmallri
Joined: 12 Aug 2004 Posts: 1634 Location: Perth, Australia
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Re: CCS MMCSD & FAT32 Drivers on SD - Working for anyone |
Posted: Tue Oct 14, 2008 6:07 am |
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Anonymous wrote: | I only want to hear from people with success using the included ex_fat.c with the mmcsd.c and fat.c (in FAT32 mode).
It's not working for me.
Thanks,
-Ben |
Based on the above, you don't want to read my post :-)
I spent a lot of time developing FAT libraries for CCS and MCHP compilers and doing so I uncovered a hardware bug on some of Microchips SD/MMC PICTails.
**** THIS MODIFICATION ADDRESSES A HARDWARE INCOMPATIBILITY BETWEEN THE MICROCHIP AC164122 REV3 SD/MMC PICTAIL board and the MICROCHIP PICDEM HPC when fitted with a PIC18F8722 or other +5V VDD PIC ****
This modification is for SD cards that operate at 3.3 volts when working in conjunction with the HPC fitted with a PIC18F8722 PIC operating at 5.0 volts. The modification covers the removal of U1 integrated circuit which is responsible for level translation from the 5 volt PIC outputs of the SPI bus to the corresponding 3.3 volt inputs of the SD Card. U1 on the affected PICTail board is an VHCT125A manufactured by ON. According to this data sheet it's input are tolerant to 7 volts making this chip apparently a good solution as a level translator between the 5 volt PICs and the 3.3 volt SD/MMC cards. However this is not the case. When the inputs of U1 are over driven (+5volt in with 3.3Volt VDD) the switching propagation delay appears to be impacted with the result that the timing of the SPI bus is corrupted.
There are two solutions. Replace U1 with a 74xxx series device, such as the 74LCX125M, that will work correctly in this mode or replace U1 with a series of resistor dividers. Details of the latter option follows:
The modification covers the removal of U1 and installation resistor dividers on SCK, SDO and CS respectively (labels refer to the PIC). R11 (activity LED limiting resistor) is also removed as this would adversely affect the voltage divider on the CS line.
1. Remove U1 (VHCT125A)
2. Install 3.3K resistor (SMD 603) between pad U1-3 to U1-4
3. Install 3.3K resistor (SMD 603) between pad U1-6 to U1-7
4. Install 3.3K resistor (SMD 603) between pad U1-8 to U1-10
5. install 1.8K resistor (SMD 603) between pad U1-2 to U1-3
6. install 1.8K resistor (SMD 603) between pad U1-5 to U1-6
7. install 1.8K resistor (SMD 603) between pad U1-9 to U1-8
8. Remove R11 (activity LED series resistor) _________________ Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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bkamen
Joined: 07 Jan 2004 Posts: 1615 Location: Central Illinois, USA
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Posted: Tue Oct 14, 2008 8:21 am |
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Thanks for the reply.
This is a Rev. 1 PCB --- but has the VHCT125A on it - so I'm going to assume that's my culprit for all this whackiness.
I had a logic analyzer hooked to the system and it looked ok - but wow.
I'll change this out and see what the results are...
Thanks a ton,
-Ben |
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bkamen
Joined: 07 Jan 2004 Posts: 1615 Location: Central Illinois, USA
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Posted: Fri Oct 17, 2008 12:28 pm |
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I'm back.
I ordered the very parts Andrew recommended and am still where I was before.
Out of the box, the CCS drivers don't see to do anything but not work.
With reading the SD Card SPEC myself, I'm already seeing spots where the CCS drivers just didn't "follow directions".
I've had more success with pieces of code I've had to write. Oh well.
Thanks for the Help Andrew,
-Ben
p.s. If anyone has had luck with these drivers "out of the box", please feel free to share. Also, let us know which cards you were using in your testing. |
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asmallri
Joined: 12 Aug 2004 Posts: 1634 Location: Perth, Australia
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Posted: Fri Oct 17, 2008 12:50 pm |
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You could always buy my FAT implementation for CCS. It works out the box :-) _________________ Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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bkamen
Joined: 07 Jan 2004 Posts: 1615 Location: Central Illinois, USA
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Posted: Fri Oct 17, 2008 1:28 pm |
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I was helping a friend on this - so my recommendation is going to be for him to do just that.
I know the examples CCS includes are pretty much as-is, but this one should be marked with, "really really may not work in most situations - so beware."
It seems to be really that far off the mark.
By the way - on the PICtail - what kind of corruption did you end up seeing?
I'm guessing something like a data line was late in toggling behind the clock and that corrupted the data. So far, I haven't really seen anything like that (using my Agilent MSO6054a w/SPI decode).. but as a test, I even ran the SPI bus at like 200KHz (paced off timer2)
Between the old VHCT125's and these, the behavior has been pretty same.
-Ben |
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newguy
Joined: 24 Jun 2004 Posts: 1907
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Posted: Fri Oct 17, 2008 2:02 pm |
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asmallri wrote: | You could always buy my FAT implementation for CCS. It works out the box :-) |
It indeed does. No affiliation, just a satisfied customer. |
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olaf Guest
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Posted: Fri Oct 31, 2008 2:33 pm |
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... finally after about 10 hours of testing my code works with mmcsd.c and fat.c.
I'm using 1gb sd card and I think I found out why some cards work and some don't.
At first: #define MMCSD_MAX_BLOCK_SIZE 512 <- needed for sd cards
Second: if you format your sd card windows sometimes creates the file system start anywhere - don't know why but happened to me,
the pic couldn't find the file system because of this.
Best way is to use winhex and to do a physical read to check if file system starts at 0x00.
now read and write works for me |
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ShellTox
Joined: 25 Jul 2007 Posts: 16
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Posted: Wed Jan 07, 2009 7:49 am |
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Hello
olaf can you post an example on how you initialize the card? And how you read and write a file on the card?
Thank you |
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AleksBak
Joined: 23 Dec 2008 Posts: 3
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Re: ... |
Posted: Fri Jan 09, 2009 1:18 am |
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olaf wrote: | ... Second: if you format your sd card windows sometimes creates the file system start anywhere - don't know why but happened to me,
the pic couldn't find the file system because of this.
... |
Windows creates the beginning of file system as it is necessary and by rules, and that who has written this code has similar transferred it from early versions FAT, that that else worked from 5.25"disks. . And consequently does not work correctly. Besides, this programmer similar very much loves functions of division and they are located everywhere where probably in a code. (Look and you are surprised how many them). |
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andreluizeng
Joined: 04 Apr 2006 Posts: 117 Location: Brasil
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fredp
Joined: 09 Nov 2005 Posts: 2
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Posted: Tue May 04, 2010 12:59 am |
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asmallri wrote: | You could always buy my FAT implementation for CCS. It works out the box :-) |
Just tried buying your FAT implementation. Getting an error, though. Let me know how we can do it as I'd like to buy it.
-- Fred |
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andreluizeng
Joined: 04 Apr 2006 Posts: 117 Location: Brasil
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Posted: Tue May 04, 2010 7:06 am |
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Hi fredp,
contact me by email,
regards,
Andre _________________ Andre |
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asmallri
Joined: 12 Aug 2004 Posts: 1634 Location: Perth, Australia
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Posted: Sat May 08, 2010 3:00 am |
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fredp wrote: | asmallri wrote: | You could always buy my FAT implementation for CCS. It works out the box :-) |
Just tried buying your FAT implementation. Getting an error, though. Let me know how we can do it as I'd like to buy it.
-- Fred |
Sorry to hear you are having an issue with paypal. Paypal sometimes has problems with buy now buttons. You can manually make payment via www.paypal.com to the account [email protected] and in the comment section put the product description from our web page. Once you have done that please send me the confirmation email from paypal - this last step catches any problems with this manual method.
++++++++++++++
Should be discussed in email or PMs. Not in CCS forum.
Pls repect this.
Ref: Forum Rules No. 6, 8.
-- Forum Moderator
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_________________ Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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