Archive for November, 2011

ICM Finals

I’ve decided to expand my midterm project for ICM by using real data this time.

Thanks to NYU Professor Dan Shiffman’s Yahoo Weather API code I had somewhere to begin with. Going through the Yahoo API wasn’t that hard and neither was parsing the data from the XML feed. I did however wanted to find locations outside the US since the original code is based on using ZIP for location. A newer version of the Yahoo Weather API uses their own WOEID which includes places outside the US but the syntax is not as easy as just entering the zip code.

I didn’t want to figure out how to map the entire WOEID database for this project so I selected a few cities for me.

I wanted to work with the flickr API as well into integrating photos appropriate to the weather condition but it wasn’t being cooperative. I ended up tagging the weather pattern data to images manually. None of the images are locally stored. This causes a bit of a slowdown but makes the file smaller.

Figures are in Farenheit.

Stuff I still like to add, conform the images to the location and weather pattern. Add a clothing suggestion. Ability to change location without having to enter the code manually for every city you want to check. Add  video for some reason or another.

Pampanga Lantern Weekend update

I decided not to fly out for Thanksgiving and instead work on my Physical Computing final project. I initially started out Thanksgiving by going through the Muppet Show episodes and getting the Open CV code to work.

My classmate Adria Navarro-Lopez suggested to use the OpenCV library instead of the Open Kinect to make things easier but sadly it was not. I got help from Lisa Park on installing the library and went to work. I got the OpenCV library to detect faces using the example of detecting faces and went through the code and send it out to the arduino via serial.

Processing code for face detection for some reason it only works on Processing 2.0a1 and not 2.0a4:

import processing.serial.;
import java.awt.Rectangle;

Serial myPort;
OpenCV opencv;

// contrast/brightness values
int contrastvalue    = 0;
int brightness
value  = 0;
String facesFound [];

void setup() {
  size(320, 240);
  //  String portName = Serial.list()[0];
  myPort = new Serial(this, Serial.list()[0], 9600);
  opencv = new OpenCV(this);
  opencv.capture(width, height);
  opencv.cascade( OpenCV.CASCADEFRONTALFACEALT );

public void stop() {

void draw() {

  // grab a new frame
  // and convert to gray;
  opencv.convert( GRAY );
  opencv.contrast( contrastvalue );
  opencv.brightness( brightness
value );

  // proceed detection
  Rectangle[] faces = opencv.detect( 1.2, 2, OpenCV.HAARDOCANNY_PRUNING, 40, 40 );

  // display the image
  image( opencv.image(), 0, 0 );

  // draw face area(s)
  stroke(255, 0, 0);

  for ( int i=0; i<faces.length; i++ ) {
    rect( faces[i].x, faces[i].y, faces[i].width, faces[i].height );
  //count number of faces and send to arduino
  // myPort.write(facesFound);

Changes contrast/brigthness values
void mouseDragged() {
  contrastvalue   = (int) map( mouseX, 0, width, -128, 128 );
value = (int) map( mouseY, 0, width, -128, 128 );

The main problem I encountered was stabilizing the response of the arduino, The LED would flicker in response and not exactly the way I wanted. But the code was running the way I wanted it. It was the same problem my media controller group had encounted with the blue LED.

Arduino code for receiving:

//arduino code for lantern
//Melissa dela Merced

const int bluePin=11;
const int greenPin=10;
const int whitePin=9;
const int yellowPin= 6;
const int redPin= 5;

int value = 0;

void setup(){

  pinMode(redPin, OUTPUT); //red LED
  pinMode(yellowPin, OUTPUT); //yellow LED
  pinMode(whitePin,OUTPUT); // white LED
  pinMode(bluePin,OUTPUT); // blue LED
  pinMode(greenPin,OUTPUT);//green LED
void loop(){
 // if (Serial.available){
    int input =;
  if (input == 0);
    digitalWrite(bluePin, LOW);
    digitalWrite(redPin, LOW);
    digitalWrite(yellowPin, LOW);
    digitalWrite(whitePin, LOW);

  if (input ==1){
    digitalWrite(bluePin, HIGH);
    /   Serial.write(input);
     for(value=0; value <=255; value++){
     analogWrite(bluePin, value);
  /* else{
   digitalWrite(bluePin, LOW);
   digitalWrite(redPin, LOW);
   digitalWrite(yellowPin, LOW);
   digitalWrite(whitePin, LOW);
  if (input ==2){
else {
   digitalWrite(redPin, LOW);
   digitalWrite(yellowPin, LOW);
   digitalWrite(whitePin, LOW);
void establishContact() {
  while (Serial.available() <= 0) {
    Serial.println(“hello”);   // send a starting message

I’ll still work on this code next week. I probably just need a capacitor or something on the LEDs to smooth out the signals.

I took advantage of the O’Reilly book sales, I picked up a number of books, namely Making things Talk by NYU Professor Tom Igoe, Arduino Cookbook and the Making Arduino Bots and Gadgets. In between coding, I would either finish drilling the LED holes in my template and reading the three books. Insert the Steve Jobs bio by Walter Issacson for a little inspiration.

I even went through learning using the matrix if that would help.


I went through figuring the resistor array that I would have to build and found this great web site to even design the array for you.


But that didn’t help. So right before the Stanford-Notre Dame game on Saturday night, I went for the temp sensor. Using the temp sensor was stable and works like a charm. But the weather has been great today so the LED remains at the great weather reading.

In this scenario I’m using a RHT03 Humidity and Temperature Sensor from Sparkfun . The RHT03 is similar to the DHT22 sensor so I installed the library made by github user nethoncho and it releases the temperature in celcius.

More to come.


Pampanga lantern – Physical Computing Final


Sooo my last idea didn’t exactly fly but that’s the way it is here. My classmates instead gave me better ideas to make this more interesting. One that resonated was suggested by Lisa Park that I should look at the work of installation artist Olafur Eliasson and his installation work in London called the Weather Project.

The Weather Project

This now inspired me to make something smaller using ordinary light bulbs and AC power. By using a servo motor to control an dimmer switch found at Lowes or Home Depot to control the brightness of the lamp.

I then started designing the lamp itself. By using 6 x 60w bulbs hanging overhead.

But then the lamp looked too ordinary. I felt like I could buy something in Ikea and it would still be better than anything I would make. I wanted to use a lamp that my family makes, but unfortunately none are in the country right now.

While talking to my brother and sister, they gave me the idea of using shells.

Photo by flickr user Beth (Nautilus Shell Studios) under a CC BY 2.0 License

Photo by flickr user Beth (Nautilus Shell Studios) under a CC BY 2.0 License

These are abundant in the Philippines but I don’t have the time to procure them at this time. I’m just making my sister bring a bunch that I can use for future project.

So then I finally settled on a Pampanga Lantern.

Photo by flickr user dementia under a BY-NA-SA-2.0 Creative Commons license.

The Pampanga lantern has Christian significance. A spin off of the more traditional “parol” or Christmas lantern, this symbolizes the star that led the three wise men to the Baby Jesus. This version is made from the Province of Pampanga in the Philippines and is only manufactured for the holidays. Each array of lights are controlled in a sequence and a parade is held every year displaying various designs from different provinces. These can lanterns can be from the size of a plate to twenty feet. The one displayed here took a year to make.

As far as I know, they don’t use Arduinos to power this.

So now I’ve decided to make mine a lantern.

I wanted to make it the traditional way by using either stiff wire or wood to build the frame and wrap paper around it. But after an afternoon of bending wire to my will, I was quickly frustrated at the slow pace and difficulty in handling 16 gauge wire. While at chuch I had the insanely great idea of using a laser cutter. DUH!

So an afternoon of hanging in the shop and talking to Tak Cheung and Oya Kosebay gave great fabrication ideas on how to build it.

I went home and designed the pattern on illustrator for the laser cutter and came up with this.

A Saturday trip to Canal Plastics and picked me up a 1/8″ 1′ x 2′ acrylic sheet of transparent plastic and headed to the lab where Jackson and Michael Columbo helped with the laser cutter as well as conforming my pattern to the laser cutter. For future reference laser people, make sure your design is inside the 1′ x 2′ dimension of the material/ laser cutter. Like really in there with a border. Think of it as a safe area.

After roughly an hour.

Now the holes I originally designed were too small now for LEDs to pass through so I has to use a hand drill with a 1/8″ bit for the LED pins to fit through. Lesson learned. But at the same thing it gave me practice on using a hand drill while watching PAC12 footbal over the weekend. Go Trojans!!

Now for the wiring and / programming part. I’m planning to use copper tape and the wiring board in a separate device which will hang from the ceiling and basically just keep the lights on the board. I’ve etched the colors as well and will use paper to cover it and diffuse the light. Think of it like the USS Enterprise saucer section but hanging on the wall.

Photo copywright of Paramount Pictures

I’m thinking of being able to switch between two sensors or one or whichever works. I’m currently in possesion of the humidity and temperature sensor RHT03 from sparkfun instead of a thermistor. Using a wonderful library available on the arduino website it maps the RHT03 the same way. It’s technically a digital sensor so it’s pretty much straightforward.

To measure person presence, an infrared sensor would be perfect but I’ve spent my money on LEDs then the kinect happened.

Yes the Xbox Kinect that was once a toy and now a hackers device and something I already have. I just plan on using processing to get the serial data from the IR cam of the kinect using the Open Kinect library since I don’t really need to map out a person at this time over the OpenNI library and send that data to the arduino to measure people presence.

The other option is to use the current data that I’m getting from my ICM project final which gets the weather from the Yahoo Weather API and send it serial to the arduino.

It’s something to work on the holidays before the big cruch for December. Hopefully I’ll be finished with most of this weekend and Happy Holidays!



Final Project for Physical Computing

Thinking of a final project is hard. Like I need ice cream to get through this hard. At first I wanted to make a robot hand being controlled by a glove. than I listed the parts I would need and that posed a significant technical problem in itself.

I wanted the glove and the robot hand separate from each other. So how do I make two arduinos talk to each other? Given the time I had and the current knowledge I have of arduinos that was a pretty big task I have there. Not to mention the type of motor I wanted to use for the robot. It would a be cross between the servo and the stepper motor of at least 6 to control. Note that these just make up the hand and the the arm, the arm is a different story but I think I could get through it by using a solenoid. But after testing the flex sensor (I know I should’ve learned from my stupid pet trick) it’s a pain to configure.

So on to the next challenge. I wanted to make an array of grass/ rice field swaying to the wind. I would use microphones to sense the wind/ noise and they would move accordingly. The mic or at least the one I was using is a pain. I couldn’t get a stable range and according to the internet I shoudl order another type of mic instead.

So now on to the real one. Somewhat similar to my ICM project but in a physical sense. I’ll be illuminating an array of LEDs based on the room/ outside temperature. Inspired by my MUJI Ultrasonic Aroma diffuser and relaxing thing it gives me.

I wanted to make one for the weather. Using a humidity and temperature sensor that I can detach from the unit so I can stick it outside my window if needed will give the outside temp and give me visual display using LEDs. I can’t seem to wrap my head around the entire farenheit scale and keep referring to my celcius range to decide what to wear.

In the event that I run out of time working with the thermmo sensor I’ll import the sensor data through processing and send them to the LED lamp.

While at work I saw the cd spindle case and thought that it would be a perfect enclosure for the lamp. I’ll use a frosting paint inside so I can diffuse the light better.

cd spindle

What are your thoughts about it?

Graffiti in a can/ media controller

Inspired by “Picasso’s Drawing with Light” we wanted to make something similar but instead of taking pictures, we would be using live video.

While Picasso used a slow shutter speed and a quick hand with a flashlight to create the images. We used arduino and processing to create our own “graffiti can”.

Initially we wanted to only use an accelerometer to track the movement on the screen but that proved to be very challenging since there was a a lot of computational math involved in converting the acceleration of the sensor to actual X and Y points on the screen.

After consulting ITP Resident Greg Borenstein he suggested that we should just track a light pointed at the camera in processing to create the images instead of the accelerometer. This was a last minute code change which changed our approach completely. But using examples in processing, it shortened the time to buld the code.

graffiti can
Here we are building the code and can at the same time.

graffiti can

Adria testing the serial connection.

graffiti can

Serial input coming in.

graffiti can

Wiring for the red can.

graffiti can

We opted for a smaller breadboard to make things lighter and compact inside.

graffiti can

This might have worked better in another manner, but I mounted the arduino uno and the breadboard back to back on a strip of corrugated cardboard to make things easier to dismantle and attack by just screwing them.

graffiti can

One slight problem, the 9V power connector was sticking out.

graffiti can

But eventually everything fit but cramming it all in.

graffiti can

We used alligator clips to be able to quickly attach and detach the board from the super bright LED if we had to make any changes.

Getting the bluetooth to work was very tricky, because in order for the bluetooth to work, the BT chip must be disconnected while uploading the code for the arduino and attaching it afterwards. The BT will not pair with the computer unless the sketch was running. It took a bit of wrangling but it eventually worked.

We became ambitious and worked on a second can.

graffiti can

We also started using an external USB camera to make the video resolution a bit better. But, like the BT it was a challenge to get these two to work as well.

graffiti can

Adria here with last minute changes to can.

graffiti can

Crunch time! Need to fit everything inside working!

graffiti can

Red vs Blue

Thank you Veronika and Lisa for the documentation photos and videos!

Graffiti Can Members

Adria Navarro-Lopez
Veronika Dubrovskaya
Melissa dela Merced
Joseph McCagherty