Run a loop at defined intervals on Arduino.

gistfile1.cpp

/* Run a loop at defined intervals.
   This was tested with an Arduino Uno.
   Other boards might require tweaking of the boardFrequency constant.
*/

/* How many times per second timedLoop() gets executed */
int loopFrequency = 1;

void timedLoop() {
  /* Do stuff. */
}

const int boardFrequency = 14796;
int freqTimer = 0;

void loop() {
  if ((freqTimer % (boardFrequency / loopFrequency)) == 0) {
    freqTimer = 0;
    timedLoop();
  }
  freqTimer++;
}

To be safe, you should also do freqTimer = 0 before timedLoop(), and make it an int.

Good point, thanks!