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Koska
Joined: 05 Dec 2014
Posts: 3
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| fwrite or f_write and what library do they need? |
 Posted: Sat Dec 20, 2014 1:41 pm |
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Hello,
I need to use the function fwrite() in my code. From the link below I understood it is necessary to include at the top the library
http://www.tutorialspoint.com/c_standard_library/c_function_fwrite.htm
But I built my project with CCS 5 and I got the following error:
*** Error 12 "code.c" Line 280(9,10): Undefined identifier -- fwrite
So I went to the folder drivers into PICC and I opened to check the content of stdio.h and I could see there is nothing there about fwrite.
| Code: |
///////////////////////////////////////////////////////////////////////////
//// (C) Copyright 1996,2003 Custom Computer Services ////
//// This source code may only be used by licensed users of the CCS C ////
//// compiler. This source code may only be distributed to other ////
//// licensed users of the CCS C compiler. No other use, reproduction ////
//// or distribution is permitted without written permission. ////
//// Derivative programs created using this software in object code ////
//// form are not restricted in any way. ////
///////////////////////////////////////////////////////////////////////////
#ifndef _STDIO
#define _STDIO
#include <string.h>
#ifndef getc
#define getc getch
#define getchar getch
#define puts(s) {printf(s); putchar(13); putchar(10);}
#define putc putchar
#endif
/* maps error number to an error message. Writes a sequence of characters to
stderr stream thus: if s is not null then string pointed to by s follwed by
a colon (:) and a space and the appropriate error message returned by strerror
function with argument errno
Returns: no value
*/
#ifdef _ERRNO
void perror(char *s)
{
if(s)
fprintf(STDERR,"%s: ",s);
fprintf(STDERR,"%s\r\n",strerror(errno));
}
#endif
#endif |
So my question is: Should I include another function and what I read is not correct for CCS, or the problem is my version of CCS has a corrupted stdio.h? Probably the problem is completly different to what I'm thinking.
In Addition, I was reading in this forum trying to find a solution on my own, and I saw some people use f_write() instead. Is is a better option? I couldn't find much information about f_write
Thank you very much for your help!
Last edited by Koska on Sat Dec 20, 2014 4:17 pm; edited 1 time in total |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sat Dec 20, 2014 2:55 pm |
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I assume this is for an SD card. What drivers are you using to interface
to the SD card ?
If you use the CCS fat.c driver, then the comments at the top of the file
say to use the fatwrite() function. The file is in this directory:
| Quote: | | c:\program files\picc\drivers\fat.c |
| Quote: | | or the problem is my version of CCS has a corrupted stdio.h? |
stdio.h is not corrupted. |
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Koska
Joined: 05 Dec 2014
Posts: 3
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| Posted: Sat Dec 20, 2014 3:49 pm |
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Thank you for your reply PCM Programmer. But actually I'm not trying to write on a SD card. I'm trying to send information that I previously read from a SD card via Bluetooth.
So what I have is a stream called BT:
| Code: |
#use RS232(UART, baud = 115200, xmit = PIN_C6 ,rcv = PIN_C7, PARITY = N, bits = 8, stop = 1, stream = BT)
char buffer_data[129];
int NumOfBytes = 128;
int32 Address = 0xXXXXXXXX;//any address
//Here I read from the SDcard. I wrote this function using mmcsd.c
GetFileContent(Address, NumOfBytes, &buffer_data); |
At this point I have in buffer_data the bytes I want to send. What I was doing before, and worked perfectly with .txt was this:
| Code: | buffer_data[NumOfBytes] = 0x00;// To set an end of the relevant data
printf(BT, buffer_data); |
But the problem is when I try to send a .pdf because in memory sometimes appears the character 0x00, so printf don't send all the content of buffer_data. It will stop when finds 0x00.
So I was looking for another function where I could include the number of bytes I want that are sent. And I read about fwrite(), and I changed the printf() for:
| Code: |
fwrite (buffer_data , sizeof(char), NumOfBytes, BT); |
And here is where I found the problem I mention above. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sun Dec 21, 2014 8:19 pm |
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There is no built-in fwrite() function. I suggest that you use fputc()
in a for() loop to send the data. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19350
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| Posted: Mon Dec 22, 2014 3:55 am |
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Understand, that 'fwrite' is for dealing with a file.
The PIC unless you have an added 'filesystem' like an SD card attached, does not have a filesystem available/involved. Hence no fwrite type functions.... |
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Koska
Joined: 05 Dec 2014
Posts: 3
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| Posted: Mon Dec 22, 2014 6:29 am |
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| Ok. Thank you for your answers and recommendations. |
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