int In1 = 7;
int In2 = 8;
int ENA = 5;
int SPEED = 255;
int In3 = 4;
int In4 = 6;
int ENB = 2;
int In5 = 10;
int In6 = 9;
int ENA2 = 11;
const int buttonPin = 3;
int stop = 0;

unsigned long myDebugPrintTimer = 0;                   // Timer-variables MUST be of type unsigned long
const byte    OnBoard_LED = 13;


void setup() {
  // if you want to use serial printning
  // you have to do a call to function Serial.begin(baudrate);
  Serial.begin(115200);
  Serial.println("Setup-Start");
  pinMode(In1, OUTPUT);
  pinMode(In2, OUTPUT);
  pinMode(ENA, OUTPUT);
  pinMode(In3, OUTPUT);
  pinMode(In4, OUTPUT);
  pinMode(ENB, OUTPUT);
  pinMode(In5, OUTPUT);
  pinMode(In6, OUTPUT);
  pinMode(ENA2, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);
}


void loop()  {
  oncePerSecondPrintDebugInfo();

  if (digitalRead(buttonPin) == LOW ) {
    // Button was pressed
    // Start the code sequence

    Serial.println("Button pressed. Running code...");
    digitalWrite(In1, HIGH);
    digitalWrite(In2, LOW);
    Serial.println("A Motor1 Right");
    delay(1000);

    digitalWrite(In1, LOW);
    digitalWrite(In2, LOW);
    Serial.println("B Motor1 Stop");
    delay(2000);

    digitalWrite(In1, LOW);
    digitalWrite(In2, HIGH);
    Serial.println("C Motor1 Left");
    delay(1000);

    digitalWrite(In1, LOW);
    digitalWrite(In2, LOW);
    Serial.println("D Motor1 Stop");
    delay(2000);
    analogWrite(ENA, SPEED);

    digitalWrite(In3, HIGH);
    digitalWrite(In4, LOW);
    Serial.println("E Motor2 Right");
    delay(1000);

    digitalWrite(In3, LOW);
    digitalWrite(In4, LOW);
    
    digitalWrite(In3, LOW);
    digitalWrite(In4, HIGH);
    Serial.println("F Motor2 Left");
    delay(1000);

    digitalWrite(In3, LOW);
    digitalWrite(In4, LOW);
    Serial.println("G Motor2 Stop");
    delay(2000);

    analogWrite(ENB, SPEED);

    digitalWrite(In5, HIGH);
    digitalWrite(In6, LOW);
    Serial.println("H Motor3 Right");
    delay(1000);

    digitalWrite(In5, LOW);
    digitalWrite(In6, LOW);
    Serial.println("I Motor3 Stop");
    delay(2000);

    digitalWrite(In5, LOW);
    digitalWrite(In6, HIGH);
    Serial.println("J Motor3 Left");
    delay(1000);

    digitalWrite(In5, LOW);
    digitalWrite(In6, LOW);
    Serial.println("K Motor3 Stop");
    delay(2000);

    analogWrite(ENA2, SPEED);

    Serial.println("Code sequence ended.");
    digitalWrite(In1, LOW);
    digitalWrite(In2, LOW);
    digitalWrite(ENA, stop);
    
    digitalWrite(In4, LOW);
    digitalWrite(In5, LOW);
    digitalWrite(ENB, stop);
    
    digitalWrite(In5, LOW);
    digitalWrite(In6, LOW);

    analogWrite(ENA2, stop);
  }
}


// easy to use helper-function for non-blocking timing
boolean TimePeriodIsOver (unsigned long &startOfPeriod, unsigned long TimePeriod) {
  unsigned long currentMillis  = millis();
  if ( currentMillis - startOfPeriod >= TimePeriod ) {
    // more time than TimePeriod has elapsed since last time if-condition was true
    startOfPeriod = currentMillis; // a new period starts right here so set new starttime
    return true;
  }
  else return false;            // actual TimePeriod is NOT yet over
}


void BlinkHeartBeatLED(int IO_Pin, int BlinkPeriod) {
  static unsigned long MyBlinkTimer;
  pinMode(IO_Pin, OUTPUT);
 
  if ( TimePeriodIsOver(MyBlinkTimer, BlinkPeriod) ) {
    digitalWrite(IO_Pin, !digitalRead(IO_Pin) );
  }
}


void oncePerSecondPrintDebugInfo() {

  if ( TimePeriodIsOver(myDebugPrintTimer,1000) ) {
    Serial.print("IO-Pin No ");
    Serial.print(buttonPin);
    Serial.print(" has state ");
    if (digitalRead(buttonPin) == LOW) {
      Serial.print("LOW");      
    }
    else {
      Serial.print("HIGH");      
    }
    Serial.println();
  }
}