arduino_from_processing.ino

String fromProcessing;

void setup() {
  Serial.begin(9600);
  pinMode(13, OUTPUT);
}

void loop() {
  while (Serial.available() > 0) {
    char recieved = Serial.read();
    // si le caractère recu est le caractère de stop
    if (recieved == '#') {
      Serial.print(fromProcessing);
      if(fromProcessing == "hello world") {
        digitalWrite(13, HIGH);
      }
      else {
        digitalWrite(13, LOW);
      }
      fromProcessing = "";
    }
    else {
      fromProcessing += recieved;
    }
  }
}

import processing.serial.*;
Serial myPort;
void setup() {
  size(200, 200);
  String portName = Serial.list()[0]; // récupérer le premier des ports
  myPort = new Serial(this, portName, 9600); // ouvrir le port
}
void draw() {
  if (mousePressed) {
    myPort.write("hello world#"); // allumer la led
    background(255);
  } else {
    myPort.write("hello#"); // éteindre la led
    background(0);
  }
}