// Timer Interrupts by ISR
// 


// Variables
bool LED_STATE1 = true; 
bool LED_STATE2 = true; 

void setup() {
  
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);

  cli();        // Stop interrupts for till we make the settings 

  // Timer 1 (interrupt each 100ms)
  TCCR1A = 0;             // Reset entire TCCR1A to 0
  TCCR1B = 0;             // Reset entire TCCR1B to 0
  TCCR1B |= B00000100;    // Set CS12 to 1 so we get prescalar 256
  TIMSK1 |= B00000010;    // Set OCIE1A to 1 so we enable compare match A
  OCR1A = 6250;           // Finally we set compare register A to this value  
  

  // Timer 2   )interrupt each 8.128ms)
  TCCR2A = 0;             // Reset entire TCCR1A to 0
  TCCR2B = 0;             // Reset entire TCCR1B to 0
  TCCR2B |= B00000111;    // Set CS12 to 1 so we get prescalar 1024
  TIMSK2 |= B00000100;    // Set OCIE1B to 1 so we enable compare match B
  OCR2B = 127;           // Finally we set compare register B to this value  

  sei();  // Enable back the interrupts

}


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

}

// With the settings above, this IRS will trigger each 8.128ms


// With the settings above, this IRS will trigger each 100ms
ISR(TIMER1_COMPA_vect) {
  TCNT1 = 0;   // First, set the timer back to 0 so it resets for nets interrupt
  LED_STATE1 = !LED_STATE1;       // Invert LED state
  digitalWrite(5, LED_STATE1);    // Write new state to the LED on pin D5
}

ISR(TIMER2_COMPB_vect) {
  TCNT2 = 0;
  LED_STATE2 = !LED_STATE2;       // Invert LED state
  digitalWrite(6, LED_STATE2);    // Write new state to the LED on pin D5
}