PicWiser Ultimate Guide To Learning Embedded C Programming

On the right is a basic C program for the Hi-Tech Compiler to blink the LED connected to pin 13 (C2).

The first line starts with a pound sign (#) and is a command to the C compiler to include the file contained in the angle brackets <>. In this case the file htc.h is included in the compilation process and provides access to information needed by the program.

The second line starts with 2 forward slashes // and indicates to the compiler that everything after (and including) the slashes is a comment and will not generate and code. The double slashes are actually a recent convention from C++ code but has been adopted in most C compilers. Standard C comments are contained between /* and */ as shown in lines 9 through 13.

#include <htc.H>
//---------------------------------------------
// file: blinkled.c
// description: First PicWiser project
// author: Emicros
// compiler: Hi-Tech
//---------------------------------------
/*---------------------------------------
** function: TimerISR
** description: This is just a place
** holder for now
** and isn't used in the program.
**-------------------------------------*/
void interrupt TimerISR( void )
{
   if( (TMR1IE) && (TMR1IF) )
   {
      TMR1IF = 0;
   }
}

/*---------------------------------------
** function: main()
** description: This is the main function.
**--------------------------------------*/
void main( void )
{
   TRISC = 0b11111011;
   while( 1 )
   {
      PORTC = 0b00000100;
      _delay( 100000 );
      _delay( 100000 );
      PORTC = 0b00000000;
      _delay( 100000 );
      _delay( 100000 );
   }
}