#define T_BUTTON_PIN 8
#define B_BUTTON_PIN 9
#define SPEAKER_PIN 5

#define N 7
uint16_t halfPeriodTimer[N] = {10208, 7648, 7648, 7648, 6816, 6080, 6080}; // 1:1 timer counts
uint8_t i = 0;

void setup() {
  pinMode(T_BUTTON_PIN, INPUT);
  pinMode(B_BUTTON_PIN, INPUT);
  pinMode(SPEAKER_PIN, OUTPUT);

  // Timer1 setup (16-bit)
  TCCR1A = 0;              // Normal mode
  TCCR1B = 0;              // Stop timer
  TCNT1 = 0x10000 - halfPeriodTimer[i];//Load the counts.  
}

void loop() {
//Top button, uses the microSecondDelay() function. 
  if (digitalRead(T_BUTTON_PIN) == LOW) {
    while (digitalRead(T_BUTTON_PIN) == LOW) {
      microSecondDelay(halfPeriodTimer[i] / 16); //No. of counts divided by counts/sercond to find time to finish the counts.
      digitalWrite(SPEAKER_PIN, !digitalRead(SPEAKER_PIN));//Toggle the speaker pin.
    }
    i = (i + 1) % N; //Cycle back to the first element when it reaches the end. 
  }

//Bottum button, uses Timer 1
  if (digitalRead(B_BUTTON_PIN) == LOW) {
    while (digitalRead(B_BUTTON_PIN) == LOW) {
      TCCR1B |= (1 << CS10);   // Prescaler set to 1 and also start the timer. Or use TCCR1B |= B00000001  
      while ((TIFR1 & (1 << TOV1)) == 0);//While counting,TOV1 is 0
      TCCR1B = 0x00;//Stop the timer when it gets out of the While loop
      TIFR1 |= (1 << TOV1);//Write a 1 to TOV1 to reset TOV1 to 0 (I know this sounds weird). 
      TCNT1 = 0x10000 - halfPeriodTimer[i];//Reload the counts.
      digitalWrite(SPEAKER_PIN, !digitalRead(SPEAKER_PIN));
    }
    i = (i + 1) % N;
  }
}

void milliSecondDelay(uint16_t ms) {
  for (uint16_t i = 0; i < ms; i++) {
    microSecondDelay(1000);
  }
}

void microSecondDelay(uint16_t us) {
  for (uint16_t i = 0; i < us; i++) {
    asm volatile("nop");
    asm volatile("nop");
    asm volatile("nop");
    asm volatile("nop");
    asm volatile("nop");
    asm volatile("nop");
    asm volatile("nop");
    asm volatile("nop");
    asm volatile("nop");
  }
}