CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to support@ccsinfo.com

const char pointer problem

 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
Raul
Guest







const char pointer problem
PostPosted: Wed Jan 08, 2003 2:48 pm     Reply with quote

I'm writing a driver for a custom display which uses a menu system. I defining my text library I decided to use constant character arrays for my text. I then attempt to point to the individual characters for the printing of text. I am using version 3.129 of the compiler and am programming for a PIC18F6720. Here is what I am having problems with.

// In the header file
const char test1[] = "TEST";

void Print_String(const char *ch);

// In function library
void Print_String(const char *ch)
{
int8 x = 0;
while(ch[x] != NULL)
{
w_data = (int)ch[x];
wr_data(); // Sends data to display
x++;
}
}

// Somewhere in code
Print_String(test1);

Now when I try to compile, the compiler stops when it gets to my function declaration, more specifically at the 'char' declaration and I get a message that says 'Expecting a , or )'. I've used this method with a couple other compilers and one being Microchips C17 and it worked fine. Is there a fix or some work around for this?
___________________________
This message was ported from CCS's old forum
Original Post ID: 10543
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

View user's profile Send private message

Re: const char pointer problem
PostPosted: Wed Jan 08, 2003 3:08 pm     Reply with quote

:=I'm writing a driver for a custom display which uses a menu system. I defining my text library I decided to use constant character arrays for my text. I then attempt to point to the individual characters for the printing of text.
------------------------------------------------------
CCS doesn't allow pointers to constant strings.
If you want to pass a pointer, you first have
to copy the string into a ram array by using
the strcpy() function.

But you can still use constant strings.
The following program shows how you could
send the string to an RS-232 terminal, or
to an LCD.

Also, the printf() function can have its
output redirected to another function.
See the manual for info on this.


#include "c:\program files\picc\devices\16F877.h"
#fuses HS,NOWDT,NOPROTECT,PUT,BROWNOUT, NOLVP
#use Delay(clock=8000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)

#include <lcd.c>

const char test1[] = "TEST";

//===============================================
void main()
{
printf(test1);
lcd_putc(test1);


while(1); // Prevent PIC from going to sleep
}
___________________________
This message was ported from CCS's old forum
Original Post ID: 10544
johnpcunningham
Guest







Re: const char pointer problem
PostPosted: Wed Jan 08, 2003 3:09 pm     Reply with quote

This compiler does not allow pointers to constants. You can use an addressing mode to send the characters.

EXAMPLE:

const char line_1[] ="my data";
char i = 0;

while( i != sizeof(line_1)
{
write_data(line_1[i++]);
}
___________________________
This message was ported from CCS's old forum
Original Post ID: 10545
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group