Question

I’m working on a PIC 18f4685 using MPLabs C18 C-compiler and I’m having issue when I try and create an array of phrases that I want to print out to my LCD.

If I use Codeblocks with gcc and enter this code it prints out what I expect to the console…test1 test2 test3 test4:

char *test[]={"test1","test2","test3","test4"};
printf("%s %s %s %s\n",test[0],test[1],test[2],test[3]);

However, if I use this code in C18:

    char *phrase[]={"test1","test2"};

I get warnings saying type qualifier mismatch in assignment and when I program the chip it spits out garbage to the LCD, which I kinda expected it would do.

What is the proper way to declare my phrases because something is obviously incorrect?

Answer 1

Apparently string literals are rom const char[N] in MPLab C. So you need to declare your object like this:

rom const char *rom test[]={"test1","test2","test3","test4"};

In MPLAB C18 C COMPILER USER’S GUIDE, there is a chapter named ISO DIVERGENCES (2.7) and 2.7.3 refers to string literals.

From 2.7.3:

When using MPLAB C18, a string table in program memory can be declared as:

rom const char table[][20] =   { "string 1", "string 2",  
                                 "string 3", "string 4" }; 
rom const char *rom table2[] = { "string 1", "string 2", 
                                 "string 3", "string 4" };