libstock fat32 library and SPI use for other communications

[robfaz]

Hi,
I'm using the fat32 libstock library routines to write a file on an sd card and everything is ok, but if I add in the program setting spdr for communication via spi with other devices happens that new program write operations on files are not complete and more precisely "mmc_error : = FAT32_Write (fHandle , @bufferr, 100); " Returns mmc_error = 255.
I have done numerous tests and the problem occurs after the first time after the first time you perform an assignment operation to spdr for example spdr: = c.
I attached a picture of the code.

[marina.petrovic]

Hi,

Please, can you tell me which microcontroller (and hardware) you use?
If you can send me some small project (zipped project folder) that represent problem that you have,
so I can test it on my system and try to find source of the problem.

Best regards,
Marina

[robfaz]

I use atmega32 and easyavr5a
this is the program:
program a32;
const CR_ : char = 0x0D;
const LF_ : char = 0x0A;
VAR
bufferr:string[32];
Mmc_Chip_Select : sbit at PORTB.B2;
Mmc_Chip_Select_Direction : sbit at DDRB.B2;
fHandle : short;
c,c1,mmc_error:BYTE;
a:string[3];
aa:array[4] of char;
txt : array[12] of char;
Begin
PORTA:=%10000001;
DDRA:=%10000011;
PORTB:=%00011111;//.............
DDRB:=%10110100;
PORTC:=%00000011;//....................
DDRC:=%11111101; //
PORTD:=%00011011;//.....................
DDRD:=%01111110;
UART1_Init(9600);
DELAY_MS(200);
//FINE INIZIALIZZAZIONE UART
//INIZIALIZZAZIONE SPI
SPI1_Init_Advanced(_SPI_MASTER, _SPI_FCY_DIV2, _SPI_CLK_LO_LEADING);
//FINE INIZIALIZZAZIONE SPI}
UART1_WRITE_TEXT('-----------------------------start------------------------------------------- ');
uart1_write (cr_);
uart1_write(lf_);
MMC_ERROR:=1;
while (mmc_error<>0) do
begin
UART1_WRITE_TEXT('start FAT32_Dev_Init----- ');
mmc_error := FAT32_Dev_Init () ;
ByteToStr(mmc_error,a);
UART1_WRITE_TEXT(a);
uart1_write (cr_);
uart1_write (lf_);
end;
UART1_WRITE_TEXT('end FAT32_Dev_Init----- ');
uart1_write (cr_);
uart1_write (lf_);
for c:=0 to 32 do
begin
memcpy(@bufferr+c,45,1);
end;
MMC_ERROR:=1;
while (mmc_error<>0) do
begin
UART1_WRITE_TEXT('start FAT32_Init () ----- ');
mmc_error:=FAT32_Init () ;
ByteToStr(mmc_error,a);
UART1_WRITE_TEXT(a);
uart1_write (cr_);
uart1_write (lf_);
end;
UART1_WRITE_TEXT('end FAT32_Init () ----- ');
uart1_write (cr_);
uart1_write (lf_);
txt:='datiacce.txt';
fHandle:=-1;
while (fHandle<0) do
begin
UART1_WRITE_TEXT('START FAT32_Open --------');
fHandle:=FAT32_Open(@txt, FILE_WRITE_F32);
//FAT32_Open('datiacce.txt', 1 );
ShortToStr(fHandle,aa);
UART1_WRITE_TEXT(aa);
uart1_write (cr_);
uart1_write (lf_);
end;
UART1_WRITE_TEXT('END FAT32_Open -------');
uart1_write (cr_);
uart1_write (lf_);
UART1_WRITE_TEXT('start first FAT32_Write ----');
uart1_write (cr_);
uart1_write (lf_);
mmc_error:=FAT32_Write(fHandle , @bufferr, 32) ;
ByteToStr(mmc_error,a);
UART1_WRITE_TEXT('end first FAT32_Write----');
UART1_WRITE_TEXT(a);
uart1_write (cr_);
uart1_write (lf_);
UART1_WRITE_TEXT('start second FAT32_Write ----');
uart1_write (cr_);
uart1_write (lf_);
mmc_error:=FAT32_Write(fHandle , @bufferr, 32) ;
ByteToStr(mmc_error,a);
UART1_WRITE_TEXT('end second FAT32_Write----');
UART1_WRITE_TEXT(a);
uart1_write (cr_);
uart1_write (lf_);
c:=0;
c1:=45;
while (pinb.b0=1) do
begin
porta.b7:=0;
SPDR:=c; // this instruction on atmega32 with spi configured in
//master mode transmit a byte on MOSI pin and receive a
//byte in spdr register, when I add this instruction the
// FAT32_Write instruction go bad and give error=255
DELAY_US(50);
PORTa.b7:=1;
c1:=spdr;
memcpy(@bufferr+c,@c1,1);
c:=c+1;
porta.b7:=0;
SPDR:=c; // this instruction on atmega32 with spi configured in
//master mode transmit a byte on MOSI pin and receive a
//byte in spdr register, when I add this instruction the
// FAT32_Write instruction go bad and give error=255
DELAY_US(50);
PORTa.b7:=1;
c1:=spdr;
memcpy(@bufferr+c,@c1,1);
c:=c+1;
DELAY_US(1);
if (c=32) then
begin
c:=0;
mmc_error:=1;
while ((mmc_error<>0) and (pinb.b0=1)) do
begin
UART1_WRITE_TEXT('start FAT32_Write ----');
porta.b1:=1;
mmc_error:=FAT32_Write(fHandle , @bufferr, 32) ;
porta.b1:=0;
ByteToStr(mmc_error,a);
UART1_WRITE_TEXT('end FAT32_Write----');
UART1_WRITE_TEXT(a);
uart1_write (cr_);
uart1_write (lf_);
delay_ms(700);
end;
end;
end;
mmc_error:=1;
while (mmc_error<>0) do
begin
UART1_WRITE_TEXT('start FAT32_Close-----');
mmc_error:=FAT32_Close(fhandle);
ByteToStr(mmc_error,a);
UART1_WRITE_TEXT(a);
uart1_write (cr_);
end;
UART1_WRITE_TEXT('end FAT32_Close-----');
end.

[marina.petrovic]

Hi,

I believe that I answered you on this question via e-mail, so we can continue our correspondence there.

Best regards,
Marina

[robfaz]

I know well especially the spi onboard functions on atmel atmegaavr microcontroller and i've used sucessfully that setting of spdr in many other projects.
If i write a byte in spdr register, as you can read on datasheet, start the trasmission on a spi interface and after the transmission i can read what i've received during transmission.

[robfaz]

Marina il ook the solution, in easy words is this: for work well before use a spi interface you must disable the end of spi trasmission interrupt use spi interface and reenable it before use a fat32 library.
bye bye

[robfaz]

oldspie:=SPIE_bit; //save the flag that enable spi end trasmission interrupt
portb.b3:=0;// slave select to low
spie_bit:=0;//disable spi end trasmission interrupt
spdr:=%01010101;//write spdr to start trasmission
delay_us(30);
c1:=SPSR;//read on datasheet of atmega 8
c1:=spdr;//save the received value
spdr:=%10101010;// start another trasmission
delay_us(30);
portb.b3:=1;//slave select to high
c2:=SPSR;//read on datasheet of atmega 8
c2:=spdr;//save the received value
SPIE_bit:=oldspie;//restore the saved value of the flag that enable spi end trasmission interrupt
bytetostr(c1,a);
memcpy(@bufferr+c,@a,3);
c:=c+3;
bytetostr(c2,a);
memcpy(@bufferr+c,@a,3);
c:=c+3;
portb.B2:=0;//dati letti 8 pd4
c1:=0;