Serial Communication

Recitation

// IMA NYU Shanghai
// Interaction Lab
// For sending multiple values from Arduino to Processing


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

void loop() {
  int sensor1 = analogRead(A0);
  int sensor2 = digitalRead(13);
  /*int sensor2 = analogRead(A1);
  int sensor3 = analogRead(A2);*/

  // keep this format
  Serial.println(sensor1);
  Serial.println(sensor2);
  /*
  Serial.print(",");  // put comma between sensor values
  Serial.print(sensor2);
  Serial.print(",");
  Serial.print(sensor3);
  Serial.println(); // add linefeed after sending the last sensor value
  */
  // too fast communication might cause some latency in Processing
  // this delay resolves the issue.
  delay(100);
}

// IMA NYU Shanghai
// Interaction Lab
// For receiving multiple values from Arduino to Processing

/*
 * Based on the readStringUntil() example by Tom Igoe
 * https://processing.org/reference/libraries/serial/Serial_readStringUntil_.html
 */

import processing.serial.*;
PImage photo;

String myString = null;
Serial myPort;


int NUM_OF_VALUES = 2;   /** YOU MUST CHANGE THIS ACCORDING TO YOUR PROJECT **/
int[] sensorValues;      /** this array stores values from Arduino **/


void setup() {
  size(800,500);
  background(0);
  setupSerial();
  photo = loadImage("May.jpg");
}


void draw() {
  updateSerial();
  printArray(sensorValues);
  image(photo, 0, 0, width, height);
  //ellipse(sensorValues[0], sensorValues[1], 100,100);
  // use the values like this!
  // sensorValues[0] 

  // add your code

  //
}



void setupSerial() {
  printArray(Serial.list());
  myPort = new Serial(this, Serial.list()[0], 9600);
  // WARNING!
  // You will definitely get an error here.
  // Change the PORT_INDEX to 0 and try running it again.
  // And then, check the list of the ports,
  // find the port "/dev/cu.usbmodem----" or "/dev/tty.usbmodem----" 
  // and replace PORT_INDEX above with the index number of the port.

  myPort.clear();
  // Throw out the first reading,
  // in case we started reading in the middle of a string from the sender.
  myString = myPort.readStringUntil( 10 );  // 10 = '\n'  Linefeed in ASCII
  myString = null;

  sensorValues = new int[NUM_OF_VALUES];
}



void updateSerial() {
  while (myPort.available() > 0) {
    myString = myPort.readStringUntil( 10 ); // 10 = '\n'  Linefeed in ASCII
    if (myString != null) {
      String[] serialInArray = split(trim(myString), ",");
      if (serialInArray.length == NUM_OF_VALUES) {
        for (int i=0; i<serialInArray.length; i++) {
          sensorValues[i] = int(serialInArray[i]);
        }
      }
    }
  }
}

Reflection

Before I had only worked with Processing or Arduino separately, so this was an interesting level of interaction between the two programs that was very different than what I was used to. Most of the time, the only hardware I could use with Processing was the keyboard or the mouse, but in this case, I was able to use other things which was pretty cool.