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gremi
Joined: 11 Mar 2008
Posts: 20
Location: Toulouse, France
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| Unable to write on a SD card |
 Posted: Fri Mar 14, 2008 3:00 am |
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Hello, I'm trying to write on a SD card, with the CCS library.
Here's my code :
| Code: | #include <18F4580.h>
#device PASS_STRINGS = IN_RAM
#fuses XT, NOWDT, NOPROTECT
#use delay(clock = 4000000)
#use rs232(baud=38400, xmit=PIN_C6,rcv=PIN_C7)
#use fast_io(c)
#use fast_io(e)
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<mmcsd.h>
#include<fat.h>
#byte PORTB = 6
void main()
{
FILE fichier;
char temp_buff[10];
char wcmd[]="w";
printf("\n\r*******Test writing on fat ...******************\n\r");
printf("Initialisation\n\r");
if (fat_init()) printf("Init error\n\r");
else {
printf("Initialisation OK\n\r");
strcpy(temp_buff,"toto");
if(fatopen(temp_buff, wcmd,&fichier)) printf("Error opening the file\n\r");
else printf("File opened\r");
strcpy(temp_buff,"coucou");
fatputc(temp_buff, &fichier);
fatclose(&fichier);
}
set_tris_b(0);
PORTB=0;
while(1)
{
output_high(PIN_B1);
output_low(PIN_B0);
delay_ms(200);
output_low(PIN_B1);
output_high(PIN_B0);
delay_ms(200);
}
} |
The initialisation returns 0, but I can't open the file.
If I look to the electrical signals, there's no signal on the clock wire when I try to open the file (I've put a fopen command in the infinite loop tho see that).
While the fat_init, I can see the clock signal.
I've searched on this forum, but I didn't find anything...
Can you help me??
Thanks. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Mar 14, 2008 11:30 am |
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1. Add NOLVP your #fuses. Do this in all of your programs. If the LVP
fuse is set and pin B5 (on this PIC) goes high, the PIC will lockup.
In recent versions of the compiler, CCS is automatically using NOLVP
if you don't specify it. In other words, they now use NOLVP as the default
setting. But you didn't give your version, so just to be sure, I mentioned
this.
2. You are setting the TRIS for Port B, but you didn't specify #fast_io
mode for Port B. So why set the TRIS ? The compiler will set it
automatically for you, if you use the CCS i/o functions.
| Quote: |
#include <18F4580.h>
#byte PORTB = 6
set_tris_b(0);
PORTB=0;
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3. You are setting PortB = 0 by writing to the register directly. When you
did this, you showed a reason why this is a bad programming method.
You are using the PortB address for the 16F-series PICs. The 18F-series
uses a different register address. Look in the PIC data sheet to see it.
You can avoid making a mistake like this if you use the CCS output_b()
function. That function will automatically use the correct register address
for Port B. When you write code in this way, by using output_b(), it's
called making the code "portable". It can more easily be compiled for
different PICs and it will still work. |
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gremi
Joined: 11 Mar 2008
Posts: 20
Location: Toulouse, France
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| Posted: Mon Mar 17, 2008 3:07 am |
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Hi,
1. I'm using CCS V4, so NOLVP is the default seeting.
2 and 3 : I'm using Port B only to toogle the led, I've changed my soft with output_b(0); .. but the result didn't change.
I acces to the memory card through port E and C (software SPI port).
I've also tryed with the hardware spi port, did'nt worked either.
This is the corfiguration part of the mmcsd driver :
| Code: | #ifndef MMCSD_PIN_SCL
#define MMCSD_PIN_SCL PIN_C3
#define MMCSD_PIN_SDI PIN_E1
#define MMCSD_PIN_SDO PIN_E0
#define MMCSD_PIN_SELECT PIN_E2
#endif
#use spi(MASTER, DI=MMCSD_PIN_SDI, DO=MMCSD_PIN_SDO, CLK=MMCSD_PIN_SCL, BITS=8, MSB_FIRST, IDLE=1, stream=mmcsd_spi) |
I work with a Picdem2 plus board RoH compliant (Microchip), and CCS V4 through MPLAB 8.02. |
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