ROTARY ENCODER W/ ATTINY85

#include "avr/interrupt.h";
#include "avr/io.h";

#define enc0PinDT 3
#define enc0PinCLK 4
#define vol_up_pin 0
#define vol_down_pin 1

volatile unsigned int tick = 0;
volatile unsigned long tickTime = 0;

static boolean pins_on = false;
static boolean rotating = false;
static boolean lastTick = false;


void setup()
{
  pinMode(enc0PinDT, INPUT);
  pinMode(enc0PinCLK, INPUT);
  pinMode(vol_up_pin, OUTPUT);
  pinMode(vol_down_pin, OUTPUT);

  GIMSK = 0b00100000;       // Enable pin change interrupts
  PCMSK = 0b00001000;       // Enable pin change interrupt for PB3 and PB4
  sei();                    // Turn on interrupts
}
void vol(boolean a){
  if (tick%7 == 0) {
    if (a)
      digitalWrite(vol_up_pin, HIGH);
    else
      digitalWrite(vol_down_pin, HIGH);
    pins_on = true;
  }
}
void loop()
{
  unsigned long cMillis = millis();
  if (cMillis - tickTime > 1500 && tickTime != 0 && tick != 0) tick = 0;
  /* /optional */
  if (cMillis - tickTime > 5 && tickTime !=0 && pins_on) { // ontime interval for output pins are both 5ms
    digitalWrite(vol_up_pin, LOW);
    digitalWrite(vol_down_pin, LOW);
    pins_on = false;
  }
  /* \optional */
  while (rotating) {
    delay(1); // debounce the signal by waiting 1 ms
    tickTime = millis();

    int MSB = digitalRead(enc0PinDT); //most significant bit
    int LSB = digitalRead(enc0PinCLK); //least significant bit

    if(MSB == LSB) { //CW
      if (!lastTick) tick = 0;
      tick++;
      vol(true);
      lastTick = 1;
    } else { //CCW
      if (lastTick) tick = 0;
      tick++;
      vol(false);
      lastTick = 0;
    }
    rotating = false;
  }
}
ISR(PCINT0_vect)
{
    rotating = true;
}