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kalambraka
Joined: 24 Jan 2012
Posts: 4
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| Write more than 512B in a SD card? Please help |
 Posted: Sat Jan 28, 2012 10:12 am |
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Hi guys!
I'm trying to use a SD card as data logger with tommi's code (mmc_spi_fat32.c).
I know that writes are in blocks of 512B. The problem is that I can only write 512B in the first sector. If I try to write more in the same program, it fails. The code don't change to the next sector.
But, If I write 512 bytes and I load again the same program to the PIC, then I can see 1024 bytes.
I made a test program that writes 512B to the SD card, but I can't write nothing else in the same program. How can I write more than 512 bytes?
| Code: |
#include <18F2455.h>
#device adc=10
#fuses XT,MCLR,NOWDT,NOPROTECT,NOLVP,NODEBUG,USBDIV,PLL1,CPUDIV1,VREGEN
#use delay(clock=4000000)
#use i2c(master,sda=PIN_B0,scl=PIN_B1)
#include <string.h>
#include <usb_cdc.h>
#include "mmc_spi_fat32.h"
#include "mmc_spi_fat32.c"
void initSD(){
while(MMCInit() != MMC_OK){ //espera inicialitzacio
printf(usb_cdc_putc,"Init SD fail!\r\n");
printf(usb_cdc_putc,"Try again...\r\n");
delay_ms(100);
MMCInit() == MMC_OK;
}
printf(usb_cdc_putc,"Init SD OK!\r\n");
delay_ms(100);
InitFAT();
printf(usb_cdc_putc,"Init FAT OK!\r\n");
delay_ms(100);
}
void main()
{
int8 file,gfilename[4];
int8 t[5];
int8 h[5];
int8 p[6];
int8 l=5, ln=6, i=0;
int mesure=0;
usb_cdc_init();
usb_init();
while(!usb_cdc_connected()) {} // Espera fins detectar una transmisió USB
if (usb_enumerated()){ // El PC reconeix el dispositiu
usb_task();
initSD();
strcpy(gfilename,"D.LOG");
delay_ms(100);
file = fopen(gfilename,'a'); // open EVENTS.LOG for append
delay_ms(100);
mesure=0;
while(mesure<32){ //512 BYTES
delay_ms(100);
for (i=0;i<=4;i++){
t[i]=7;
h[i]=7;
}
for (i=0;i<=5;i++){
p[i]=7;
}
delay_ms(100);
fwrite(t,l,file);
delay_ms(100);
fwrite(h,l,file);
delay_ms(100);
fwrite(p,ln,file);
delay_ms(100);
fclose(file);
mesure=mesure+1;
printf(usb_cdc_putc," %u \n\r",mesure);
}
printf(usb_cdc_putc,"Test done!\r\n");
while(1){}
}
}
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temtronic
Joined: 01 Jul 2010
Posts: 9226
Location: Greensville,Ontario
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| Posted: Sat Jan 28, 2012 1:22 pm |
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comments...
I only see 3 writes totalling 16 '7's to the file before you close it in your loop....
Stuffing the same value in every byte is very, very bad for debugging.
Using 1 character variable names is bad and went out of fashion in 1979 when Microsoft BASIC allowed 2 character variables. Use longer names to self-describe WHAT the data is. You'll be able to read it and get more help from others.
It appears you're using an SPI style card so why do you have the I2C function ?
I don't have the drivers...
#include "mmc_spi_fat32.h"
#include "mmc_spi_fat32.c"
so I can't comment on how you're passing data to it or saving it.
It is 'normal' practice to use unique data for test purposes or you'll never figure out 'bugs'. For testing 512 byte 'records', I'd save a 'record number', then known data as 'filler'. If you want to test say 1000 record the first 4 bytes could be the record number. |
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