// Serial Variables
int baud = 31250;


// MIDI Real Time Bytes
byte midi_start = 0xfa;
byte midi_stop = 0xfc;
byte midi_clock = 0xf8;
byte midi_continue = 0xfb;


// Working Variables and Pins
int nano_flip = 0;
int play_flag = 0;
byte data;

byte nano_high = B00111111;
byte lsdj_high = B00111111;


// Setup
void setup() {
  Serial.begin(baud);
  DDRB = DDRB | B00111111;
  DDRC = DDRC | B00111111;
  
  PORTC = lsdj_high;
}


// Program
void loop() {
  if(Serial.available() > 0) {
    data = Serial.read();

    if(data == midi_start) {
      play_flag = 1;
    }
    
    else if(data == midi_continue) {
      play_flag = 1;
    }

    else if(data == midi_stop) {
      play_flag = 0;
      nano_flip = 0;
    }

    else if((data == midi_clock) && (play_flag == 1)) {
      Sync();
    }
  }    
}


// Functions
void Sync() {
  if(nano_flip == 0) {
    PORTB = 0;
    nano_flip = 1;
  }

  else if(nano_flip == 1) {
    PORTB = nano_high;
    nano_flip = 0;
  }
  
  for (int i=0; i < 8; i++) {
    PORTC = 0;
    PORTC = lsdj_high;
  }
}