MicroSD Cards and SDFS

[mackrackit]

Maybe the pull-ups on pins 8 and 9 are not needed... Old habits are hard to break.

' Write to file
        FAT_src[0] = "A"
        FAT_src[1] = $d
        FAT_src[2] = $a
        FAT_src[3] = "B"
        FAT_src[4] = $d
        FAT_src[5] = $a
        FAT_src[6] = "C"
        FAT_src[7] = $d
        FAT_src[8] = $a
     FAT_src[9] = $d
     FAT_src[10] = $a 
        FAT_count = 11
    Gosub FSfwrite
    Serout2 PORTC.6, 84, [ "Write ", Dec FAT_error, $d, $a]
    If (FAT_error != 0) Then Stop

[rsocor01]

mackrackit,

Very nice. It works!! This is not in the readme.txt file. How do you know these things? Just kidding.


Now, I have another problem when trying to combine USB and SDFS. I'm not sure if I should open another thread for this problem.

When using USB with PBPL you get the next errors

ERROR: Macro USBINIT? not found in macro file.
ERROR: Macro USBSERVICE? not found in macro file.
ERROR: Macro USBIN?CBBL not found in macro file.
ERROR: Macro USBOUT?CBBL not found in macro file.

The fix for this problem is to include the 18F4550.bal file and the project files in the same directory. This solution was given by Mister_E in the next thread

http://www.picbasic.co.uk/forum/show...=macro+usbinit

Now, if I want to combine USB and SDFS I would have to use the file 18F4550.bal. But if I compile my SDFS file with this file in the same directory I get the following error

ERROR: Unable to fit variable SDC_buffer

I'm using PBP 2.50, MPASM 5.22, and MCS 3.0.0.5. Any help would be greatly appreciated. Thank you.

Robert

[mackrackit]

Unfortunately it looks like you need a chip with more memory to do both.

Any way you could use two MCUs and have them share data? Not the best solution but... it is all I can think of off the top.

[rsocor01]

Unfortunately it looks like you need a chip with more memory to do both.

Any way you could use two MCUs and have them share data? Not the best solution but... it is all I can think of off the top.

Hmmm, I problably didn't explain myself very clear . I get this SDC_buffer error running SDFS only with the file 18F4550.bal in the same directory. This file is necessary to run USB with PBPL. I haven't tried both USB and SDFS at the same time yet. I will probably open a new thread on this problem.

Robert

[mackrackit]

If you do not need the USB function of the chip then remove the bal file.
I am pretty sure PBP will include it if it is in the project directory even if you are not using it. IT being bal

[rsocor01]

mackrackit,

My project is going well. Without your help I would be still stuck trying to make this SDFS work. Thank you for your help.

After a lot of reading, I figured out a way to make USB and SDFS work. I had to modify the 18F4550.bal file. There are two versions of this file, one for USB and one for non-USB devices. The option for USB devices had some memory settings commented out. I enabled back these settings and BINGO, it worked.

Robert

[rsocor01]

mackrackit,

In my project, data is read from the MicroSD card and sent to a TFT LCD display. As you can imagine, speed is very important. Let's say that I have the following bytes in my TXT file and I want to read them

203
37
92

When you read these values with SDFS you get something like

FAT_dest[0] = 50     'ASCII number for "2"
FAT_dest[1] = 48     'ASCII number for "0"
FAT_dest[2] = 51     'ASCII number for "3"
FAT_dest[3] = 13     'ASCII number for "CR"
FAT_dest[4] = 10     'ASCII number for "LF"
FAT_dest[5] = 51     'ASCII number for "3"
FAT_dest[6] = 55     'ASCII number for "7"
FAT_dest[7] = 13     'ASCII number for "CR"
FAT_dest[8] = 10     'ASCII number for "LF"
FAT_dest[9] = 57     'ASCII number for "9"
FAT_dest[10] = 50     'ASCII number for "2"

Then, you have to do some data manipulation to obtain the bytes that you need, 203, 37, and 92. This takes too much time . Is there any way or is there any format for my TXT file that I can use were I would obtain a SDFS reading like the following?

FAT_dest[0] = 203  
FAT_dest[1] = 37
FAT_dest[2] = 92

This would speed up my program a lot and I would obtain much better graphics in my TFT display. Thank you for your help.

Robert