Question on SPI Data out on PortC.7(pic18f4550)

The following code is working...

Code:

---

SD_WE        Var    PORTA.4    ' SD card write protect
SD_WE_TRIS    Var    TRISA.4    ' SD card write protect direction
SDI        Var    PORTB.0    ' SPI data in
SDI_TRIS    Var    TRISB.0    ' SPI data in direction
SCL        Var    PORTB.1    ' SPI clock
SCL_TRIS    Var    TRISB.1    ' SPI clock direction
SD_CS        Var    PORTB.3    ' SD card chip select
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
SDO_TRIS    Var    TRISC.7    ' SPI data out direction

---

My question now is it possible to use other pin for SDO? I see it on the datasheet for Pic18F4550 PORTRC.7 is RC7/RX/DT/SDO. I tried PortD.0 and PortB.7 but not working. The reason I want to use other pin is I'm planning to use it for blue tooth module and use hardware interrupt on PortC.7.


Kind regards,
tacbanon

Yes, if you are using software SPI. Then you can put SD pin's on almost any pin on PIC.

@pedja089
Thanks for replying...I'm not really that good yet in PBP and not yet use shiftin/shiftout...but can you give a link where to start(good example) so that my end goal is to use it for the sdcard module?

Thanks in advance,
tacbanon

If you are using the SDFS from MeLabs it is built in.

Hello macrackit, I will check it out..thanks.

Kind regards,
tacbanon

I'm trying to figure it out this block of code from SDFS how to make disable hardware SPI.

Code:

---

' Initialize some values for the following subroutines
        SDC_UseHardSPI = TRUE        ' Use hardware SSP port for SPI.
        DISK_mount = FALSE        ' The card has not been initialized.
        FAT_mode = "r"                ' Read mode if not otherwise specified.
        FAT_count = 0                ' Default character count to 0.

' Skip over SD/MMC/FAT subroutines
        Goto SkipSD


' Subroutines for communicating with an SD/MMC card
' Subroutine to initialize SD card pins
InitIO:
        SD_CS = 1                ' SD card not selected.
        SD_CS_TRIS = 0                ' Output SD card chip select.
        SD_CD_TRIS = 1                ' Input card detect.

        SDO = 1                        ' Start SPI data out high.
        SDO_TRIS = 0                ' Output SPI data out.
        SDI_TRIS = 1                ' Input SPI data in.
        SCL = 1                        ' SPI clock idles high.
        SCL_TRIS = 0                ' Output SPI clock.
        Return


' Subroutine to initialize hardware SSP for SPI at less than 400kHz
OpenSPIM:
        If (SDC_UseHardSPI) Then
                SSPSTAT = %00000000        ' Sample at middle of data output time, Mode 1, 1: Transmit on idle to active clock transition.
                SSPCON1 = %00010010        ' SPI master mode, clock = Fosc/64, Mode 1, 1: Clock idle high.
                SSPEN = 1                ' Enable hardware SPI port.
        Endif
        Return


' Subroutine to initialize hardware SSP for SPI at full speed
OpenSPIMFast:
        If (SDC_UseHardSPI) Then
                SSPSTAT = %00000000        ' Sample at middle of data output time, Mode 1, 1: Transmit on idle to active clock transition.
                SSPCON1 = %00010000        ' SPI master mode, clock = Fosc/64, Mode 1, 1: Clock idle high.
                SSPEN = 1                ' Enable hardware SPI port.
        Endif
        Return


' Subroutine to release hardware SSP from SPI
CloseSPIM:
        If (SDC_UseHardSPI) Then
                SSPEN = 0                ' Disable hardware SPI port.
        Endif
        Return

---

But not really sure what to do? Hope anyone can help out...

/tacbanon

Hi,
I've never used that code but I'd probably try SDC_UseHardwareSPI = FALSE.
However, don't change the SDFS.pbp file. INCLUDE it in your program and ADD SDC_UseHardwareSPI = FALSE after including it (see the example) - it will "overwrite" the default setting.

/Henrik.

Hi Henrik,
Thanks for the response, I will try it and post here my result.

Kind regards,
tacbanon

/Henrik is correct.

This example may help.
http://www.picbasic.co.uk/forum/cont...USB-SD-LOGGING
I did comment out the pin alias in SDFS so I could change things around in my code without bothering with opening the include.

@Dave
Sorry for the late reply...thanks for the link..got it to work now.

/tacbanon