//storage variables
boolean toggle0 = 0;
boolean toggle1 = 0;
boolean toggle2 = 0;

long counter;

void setup() {
  
   cli();//stop interrupts
  // put your setup code here, to run once:

  counter = 0;
pinMode(8, OUTPUT);
  pinMode(10, OUTPUT);
pinMode(11, OUTPUT);

  pinMode(12, OUTPUT);

  pinMode(13, OUTPUT);
  
  
   TCCR2A = 0;// set entire TCCR2A register to 0
  TCCR2B = 0;// same for TCCR2B
  TCNT2  = 0;//initialize counter value to 0
  // set compare match register for 2khz increments
  OCR2A = 124;// = (16*10^6) / (2000*64) - 1 (must be <256)
  // turn on CTC mode
  TCCR2A |= (1 << WGM01);
  // Set CS01 and CS00 bits for 64 prescaler
  TCCR2B |= (1 << CS01) | (1 << CS00);   
  // enable timer compare interrupt
  TIMSK2 |= (1 << OCIE0A);

sei();//allow interrupts

}


ISR(TIMER2_COMPA_vect){//timer0 interrupt 2kHz toggles pin 8
//generates pulse wave of frequency 2kHz/2 = 1kHz (takes two cycles for full wave- toggle high then toggle low)
  if (toggle0){
    digitalWrite(8,LOW);
    toggle0 = 0;
  }
  else{
    digitalWrite(8,LOW);
    toggle0 = 1;
  }
  counter++;
}

void loop() {
  // put your main code here, to run repeatedly:

    if((counter % 1000) == 0){
        digitalWrite(12,HIGH);  

    }
    
    if((counter % 1500) == 0){
        digitalWrite(12,LOW);  

    }
    

}