String input; // for incoming serial data
  int command;
  bool vac = false; //Switch condition for vacuum
  bool blow = false; //Switch condition for blow off
  bool off = true; //Switch condition for off
  
void setup() {
  Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
  pinMode(8, OUTPUT); //Assign port 8 and 9 as digital output
  pinMode(9, OUTPUT);
  digitalWrite(9, HIGH);
  digitalWrite(8, HIGH);
}

void loop() {
  // send data only when you receive data:
  if (Serial.available() > 0) {
    // read the incoming string:
    input = Serial.readString();
    // read input data from the serial monitor
    command = input.toInt();
    // enter a command of 1 to turn on and off vac
      if (command == 1) {
        vac = !vac;
      }
    // enter a command of 3 to turn on and off blow off
      if (command == 3) {
        blow = !blow;
      }
      /*Serial.print("vac: ");
      Serial.println(vac);
      Serial.print("blow: ");
      Serial.println(blow);
      Serial.print("off: ");
      Serial.println(off);*/
        
    if (vac && blow || !vac && !blow) {
      vac = false;
      blow = false;
      Serial.println("off");
      // due to circuit design, a HIGH digital output corresponds to off for the ejector signal
      digitalWrite(9, HIGH);
      digitalWrite(8, HIGH);
    }
    else if (blow) {
      Serial.println("blow on");
      // digital pin 8 is connected to blow off
      digitalWrite(8, LOW);
      digitalWrite(9, HIGH);
      delay(300);
      digitalWrite(8, HIGH);
      blow = false;
      vac = false;
      Serial.println("off");
    }
    else if (vac) {
      Serial.println("vacuum on");
      // digital pin 9 is connected to vacuum
      digitalWrite(9, LOW);
      digitalWrite(8, HIGH);
    }
  }
}