void setup() {
  Serial.begin(9600);
}

void loop() {
  int micLevel = analogRead(A0);
  Serial.println(micLevel,DEC);
}

Serial port;

void setup() {
  port = new Serial(this, "/dev/ttyACM0", 9600);
}

void draw() {
  String s = "";
  if(port.available() > 0) {
     s = port.readStringUntil(10);
     println(s);
  }
}