Process

Arduino and Processing communication

Code for Arduino

char val; // Data received from the serial port

int ledPin = 13; // Set the pin to digital I/O 13

boolean ledState = LOW; //to toggle our LED

void setup() 

{

  pinMode(ledPin, OUTPUT); // Set pin as OUTPUT

  //initialize serial communications at a 9600 baud rate

  Serial.begin(9600);

  establishContact();  // send a byte to establish contact until receiver responds 

}

void loop()

{

  if (Serial.available() > 0) { // If data is available to read,

    val = Serial.read(); // read it and store it in val

    if(val == '1') //if we get a 1

    {

       ledState = !ledState; //flip the ledState

       digitalWrite(ledPin, ledState); 

    }

    delay(100);

  } 

    else {

    Serial.println("Please, WORK!"); //send back a hello world

    delay(50);

    }

}

void establishContact() {

  while (Serial.available() <= 0) {

  Serial.println("A");   // send a capital A

  delay(300);

  }

}

Code for Processing

import processing.serial.*; //import the Serial library

 Serial myPort;  //the Serial port object

 String val;

// since we're doing serial handshaking, 

// we need to check if we've heard from the microcontroller

boolean firstContact = false;

void setup() {

  size(200, 200); //make our canvas 200 x 200 pixels big

  //  initialize your serial port and set the baud rate to 9600

  myPort = new Serial(this, Serial.list()[2], 9600);

  myPort.bufferUntil('\n'); 

}

void draw() {

  //we can leave the draw method empty, 

  //because all our programming happens in the serialEvent (see below)

}

void serialEvent( Serial myPort) {

//put the incoming data into a String - 

//the '\n' is our end delimiter indicating the end of a complete packet

val = myPort.readStringUntil('\n');

//make sure our data isn't empty before continuing

if (val != null) {

  //trim whitespace and formatting characters (like carriage return)

  val = trim(val);

  println(val);

  //look for our 'A' string to start the handshake

  //if it's there, clear the buffer, and send a request for data

  if (firstContact == false) {

    if (val.equals("A")) {

      myPort.clear();

      firstContact = true;

      myPort.write("A");

      println("contact");

    }

  }

  else { //if we've already established contact, keep getting and parsing data

    println(val);

    if (mousePressed == true) 

    {                           //if we clicked in the window

      myPort.write('1');        //send a 1

      println("1");

    }

    // when you've parsed the data you have, ask for more:

    myPort.write("A");

    }

  }

}