MicroSD Cards and SDFS

[mackrackit]

When not using Write Protect do a search through SDFS for "SD_WE" and comment out anything to do with it. It only shows up in about 6 places.
Comment this

SD_WE_TRIS = 1

And all occurrences of this

If (SD_WE) Then
        FAT_error = CE_WRITE_PROTECTED
        Return        ' Return Byte FAT_error.
    Endif

The PIC® pin assignments will look something like this

SDI        Var    PORTB.2    ' SPI data in SD #7
SDI_TRIS    Var    TRISB.2    ' SPI data in direction
SCL        Var    PORTB.1    ' SPI clock  SD #5
SCL_TRIS    Var    TRISB.1    ' SPI clock direction
SD_CS        Var    PORTB.3    ' SD card chip select SD #1
SD_CS_TRIS    Var    TRISB.3    ' SD card chip select direction
SD_CD        Var    PORTB.4    ' SD card detect
SD_CD_TRIS    Var    TRISB.4    ' SD card detect direction
SDO        Var    PORTC.7    ' SPI data out   SD #2
SDO_TRIS    Var    TRISC.7    ' SPI data out direction

If you are not using the hardware SPI from the PIC® and need to use other pins put this in your code

SDC_UseHardSPI = FALSE

If you run into problems let us know.

[rsocor01]

If you run into problems let us know.

Thank you. As soon as I get the parts, I will start playing with the SDFS and the MicroSD card. I am sure I will have some questions.

Robert

[rsocor01]

Hi,

I finally got the parts that I needed and started playing with SDFS. Since I'm running my 18F4550 at 3.3V I connected all the MicroSD card pins directly to the PIC. I did not install the 10k resistors since my configuration is a little bit different. Do I need to use these 10K resistors?

I ran the SDTEST.BAS and it worked. It created a file TEST1.TXT with the text "ABC". I could see the file in my cell phone that runs Windows Mobile 6.1. Now, I can't read this card in my Windows XP PC. Somehow, XP does not like FAT16 format in the SD cards. How do you read your SD files in your computer? Is there any work around for this? I don't want to install Win98 in one of my old computers just for this .

Robert

[Normnet]

Now, I can't read this card in my Windows XP PC. Somehow, XP does not like FAT16 format in the SD cards. How do you read your SD files in your computer? Is there any work around for this? I don't want to install Win98 in one of my old computers just for this .

Robert

Try formatting the card with XP using right click on SD drive > format > file system FAT(FAT16).
Be sure you have the correct drive or data loss will occur.

Norm

[Normnet]

Hi,

I finally got the parts that I needed and started playing with SDFS. Since I'm running my 18F4550 at 3.3V I connected all the MicroSD card pins directly to the PIC. I did not install the 10k resistors since my configuration is a little bit different. Do I need to use these 10K resistors?
Robert

I haven't seen the wiring diagram but a 10k resistor would only be required for a 5 volt PIC to
pull up the PIC in-data line as well as others to split the PIC 5 volt lines to SD 3.3 volts.

Norm

[mackrackit]

Running at 3.3 volts I still pull up pins 8 and 9 on the full size SD cards, the remainder I run straight.

Norn is correct about the formatting. I read my FAT16 cards on XP, Vista, Vista 7, and Linux. No problems.

[rsocor01]

Hi,

Thank you guys for your help. Yes, Norm is correct about the formatting of the MicroSD card. It works .

Running at 3.3 volts I still pull up pins 8 and 9 on the full size SD cards, the remainder I run straight.

The breakout board that I got from sparkfun.com doesn't have the connection for the NC pad. Maybe, the resistor at NC is not necessary after all .

http://www.sparkfun.com/commerce/pro...roducts_id=544


Now, I have a question about SDTEST.BAS. The code to write to the card is

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

This code will write "ABC" to the card

ABC

But, for data logging I need the entries in diferent lines

A
B
C

Can you do that with SDFS? Thank you for your help.

Robert

[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