 |
 |
| View previous topic :: View next topic |
| Author |
Message |
Sid2286
Joined: 12 Aug 2010
Posts: 119
|
| Accessing Array |
 Posted: Thu Jan 02, 2014 4:49 am |
 |
|
I want to access an array and display on the LCD but getting the following error.
ERROR: previous identifier must be a pointer
how do I change my following code:?
| Code: |
#include <18F4520.h>
#device ICD=TRUE ADC=10
#fuses HS,NOLVP //,WDT128
#use delay (clock=8MHZ)
#include <flex_lcd.c>
#include <button.c>
const char* my_lib[]={"abc", "xyz", "123","ABCD"};
int8 B7 = 0; // Enter Button->B0
int8 B5 = 0; //right shift Button->B5
int8 B6 = 0; //increment Button->B6
int my_lib()
{
int* x;
while(true)
{
if(button(PIN_B6, 0, 50, 10, B6, 1))
break;
}
while(true)
{
printf(lcd_putc,"\n %c ",my_lib[x]);
delay_ms(1000);
if(button(PIN_B6, 0, 50, 10, B6, 1)) //Increment value
x++;
if(x==3)
x=0;
if(button(PIN_B7, 0, 50, 10, B7, 1)) // Enter Pressed Return Value
{
return x;
delay_ms(500);
}
}
}
void main()
{
int x;
PORT_B_PULLUPS(true);
while(True)
{
if(button(PIN_B7, 0, 50, 10, B7, 1))
{
printf(lcd_putc," \fUnits\nto Display");
delay_ms(1000);
x =my_lib();
}
printf(lcd_putc,"\n %c ",my_lib[x]);
delay_ms(1000);
}
} |
|
|
 |
Ttelmah
Joined: 11 Mar 2010
Posts: 19513
|
|
| Posted: Thu Jan 02, 2014 5:51 am |
|
|
Several things worthy of comment. Some CCS specific, and other just 'wrong'....
First, either get rid of the const keyword, or do a search here on 'pointer to constant'. In the PIC, ROM, and RAM are completely separate memory spaces. Hence a standard 'pointer', which points to RAM, can't be used to access a 'const' (stored in ROM) variable. There are ways of doing this (#DEVICE PASS_STRINGS=IN_RAM), or using the 'rom' construct, rather than 'const', which adds extra code to allow pointers to be constructed.
Then it is really bad programming practice to use the same name for a function and a variable. Avoid this. This is probably what actually gives the error.
Then though the basic construction is wrong. mylib[x] is a pointer to an array of characters, not a character, which '%c' expects....
Then you declare a pointer 'x', but nowhere do you initialise it. It could be pointing anywhere!. Then you declare x as a pointer, but the function returns an integer. |
|
|
|
|
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
|
FAQ 
Search
Register
Profile 
Log in to check your private messages 
Log in
