[Mark McLeod]

Originally Posted by Astronouth7303

I have had problems with interupts.c and timers. I use Timer 2 (and/or 1) to increment a variable and if that variable overflows, it increments another one. The problem is that I can't ever seem to get either to change. Help?

Sounds like the timers haven't been enabled in your initialization code.

Here's a sample initialization of Timer 4 to cause a 4ms interrupt.

OpenTimer4(TIMER_INT_ON &
	  T4_PS_1_16 &
	  T4_POST_1_10);
WriteTimer4(6); /* Preload timer to overflow after 4ms */

Here's the corrsponding user_routines_fast.c interrupt code.

unsigned long Clockms; // 1 millisecond clock
unsigned long Clockcs; // 100 millisecond
unsigned long Clocksec; // 1 second clock
 
static unsigned char t100ms=0;
static unsigned int t1sec=0;
 
...
 
else if (PIR3bits.TMR4IF) /* TIMER 4 INTERRUPT */
{
  /** This provides us with a clock for timing events **/
  PIR3bits.TMR4IF = 0; /* Clear Timer interrupt flag */
  WriteTimer4(6);	/* Reset Timer to overflow at 4ms */
  Clockms += 4; /* milliseconds */
  if (++t100ms >= 25)
  {
	t100ms = 0;
	Clockcs++; /* tenths of seconds */
	if (++t1sec >= 10)
	{
	  t1sec = 0;
	  Clocksec++; /* seconds */
	}
  }
}