//occurs every timer tickISR(TIMER1_COMPA_vect){ //Increase the millisecond counter totalMilliseconds++; //This applies any on-the-fly millisecond adjustment on the second if(totalMilliseconds >= 1000) { //Do we need to retard the clock? if(incrementMilliseconds < 0) { //We subtract the increment from the counter and exit //Second roll over will happen late totalMilliseconds += incrementMilliseconds; incrementMilliseconds = 0; return; } //Do we need to speed up the clock? else if(incrementMilliseconds > 0) { //We roll over the second.But instead of starting millisecond at 0 //We start at incrementMilliseconds to speed up the clock totalMilliseconds = incrementMilliseconds; incrementMilliseconds = 0; } else { totalMilliseconds = 0; } totalSeconds++; //This function handles the PWM for the charger ChargeMilliSecond();}