const int txPin = 8;
const int txPinInput = 14;
const int rxPin = 10;

unsigned long lastTimeTx = 0; // Vorherige Millis zur Zeitmessung
unsigned long T_bitTx = 100; // Intervall in Millisekunden
unsigned long lastTimeRx = 0; // Vorherige Millis zur Zeitmessung
unsigned long T_bitRx = 101; // Intervall in Millisekunden

const int applDataSize = 8;
const int maxArraySize= 20;
int rxArraySize = 20;
bool rxArray[maxArraySize];
int currentIndexRx = 0;
int lastIndexRx = 0;
int lastRxState = 0;
int bitStuffingL = 2;



void setup() {
  Serial.begin(9600); //opens serial port, sets data rate to 9600 bps

  // Define Input Pins (including PullUp Resistor)
  pinMode(14, INPUT_PULLUP);
  pinMode(15, INPUT_PULLUP);
  pinMode(16, INPUT_PULLUP);
  pinMode(17, INPUT_PULLUP);
  pinMode(18, INPUT_PULLUP);
  pinMode(19, INPUT_PULLUP);
  pinMode(20, INPUT_PULLUP);
  pinMode(21, INPUT_PULLUP);


  //Define Output Pins (LED)
   pinMode(23, OUTPUT);
   pinMode(25, OUTPUT);
   pinMode(27, OUTPUT);
   pinMode(29, OUTPUT);
   pinMode(31, OUTPUT);
   pinMode(33, OUTPUT);
   pinMode(35, OUTPUT);
   pinMode(37, OUTPUT);

  //Define BUS In- and Output
  pinMode(txPin, OUTPUT);
  pinMode(rxPin, INPUT);


  // Definitionen für Interrupt mit 50 Hz
  
  cli();//stop all interrupts

  // turn on CTC mode
  TCCR1A = 0;// set entire TCCR1A register to 0
  TCCR1B = 0;// same for TCCR1B
  TCCR1B |= (1 << WGM12);

  // Set CS11 bit for prescaler 8
  //TCCR1B |= (1 << CS11); 
  // Set CS11 bit for prescaler 256
  TCCR1B |= (1 << CS12); 
  
  //initialize counter value to 0;
  TCNT1  = 0;
  
  // set timer count for 100Hz increments
  //OCR1A = 19999;// = (16*10^6) / (100*8) - 1  
  OCR1A = 62;// = (16*10^6) / (1000*256) - 1  



  // enable timer compare interrupt
  TIMSK1 |= (1 << OCIE1A);
  
  sei();//allow interrupts
  //END TIMER SETUP


}



ISR(TIMER1_COMPA_vect) {//Interrupt at frequency of 1000 Hz
 //write your timer code here


//************* Physical Layer *************************************
  receiveUnipolar();

  if (lastIndexRx!=currentIndexRx){
      Serial.println(currentIndexRx);
    lastIndexRx= currentIndexRx;
//************* Data Link Layer  *************************************







//************* Application Layer *************************************
    if (currentIndexRx==applDataSize){

      for (int i = 0; i<applDataSize;i++){
        digitalWrite(23+(2*i), rxArray[i]);
      }
      currentIndexRx= 0;
    }




  }


}




void receiveUnipolar(){
  unsigned long currentMillis = millis();


  bool rxState = digitalRead(rxPin);

  if (rxState!= lastRxState){
    lastRxState= rxState;
    lastTimeRx= currentMillis-(T_bitRx/2);
  }

  if((currentMillis-lastTimeRx)>=T_bitRx){
    lastTimeRx= millis();;

    rxArray[currentIndexRx]= digitalRead(rxPin);
    currentIndexRx++;
  }

}




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



//************* Application Layer *************************************
 // Definition des dataArrays
 bool txArray[maxArraySize];

 for (int i =0; i< applDataSize;i++){
  txArray[i] = digitalRead(txPinInput+i);
 }



//************* Data Link Layer *************************************
 




//************* Physical Layer *************************************
sendUnipolar(txArray, applDataSize);


}


void sendUnipolar(bool* data, int dataSize){
  int i= 0;
  while(i<dataSize){
    if((millis()-lastTimeTx)>=T_bitTx){
      lastTimeTx= millis();

      digitalWrite(txPin, data[i]);

      i++;
    }
  }
}