Screaming Rapture has been a lot of fun, now in the last week now of this 3 month project, before it finally hits the ground outside the MCA in Sydney.

Last night we had a chance to have the installation in front of about 10-15 people who gave it a good workout. I noticed a lot going on just with the 30 minutes or so of people using it.

People make their noise at the centre of screen itself – even when they kbnow where the micophones are.

People love to experiment!

The sensitivity needs some fine tuning and I’ve enjoyed (reluctantly) learning about the statistical sigmoidal function, and in particular the Gompertz Curve. This curve function plays out where there is slow uptake at early stages then accelerating near the middle and a slowing near the end as saturation is reached.

Gompertz Curve

Well yes, we use the mouse all the time and it really has transformed the way computer interaction takes place, but as a form of expression, mouses really suck.

So let’s introduce some other forms of interaction.

You’ll notice that in the code in the previous sketch we set up three sensor variables.

Now we can use those to read various other sensors, a Bend Sensor and Potentiometer in our case, to change the behaviour of processing.

A. Paste this code into a new sketch.

–

/**
* Loop.
*
* Move the cursor across the screen to draw.
* Shows how to load and play a QuickTime movie file.
*/

import processing.video.*;
import processing.serial.*;
import cc.arduino.*;

Arduino arduino;
int ledPin = 13;
int sensor0 = 0;
int sensor1 = 0;
int sensor2 = 0;

Movie myMovie;

void setup() {
//println(Arduino.list());
arduino = new Arduino(this, Arduino.list()[0], 57600);
arduino.pinMode(ledPin, Arduino.OUTPUT);
noCursor();

size(640, 480, P2D);
background(0);
// Load and play the video in a loop
myMovie = new Movie(this, “station.mov”);
myMovie.loop();
}

void movieEvent(Movie myMovie) {
myMovie.read();
}

void draw() {
sensor0 = arduino.analogRead(0);
sensor1 = arduino.analogRead(1);
sensor2 = arduino.analogRead(2);
println(“Sensor0 ” + sensor0);
println(“Sensor1 ” + sensor1);
println(“Sensor2 ” + sensor2);

int moveX = sensor0;

tint(255, 20);
image(myMovie, moveX-myMovie.width/2, mouseY-myMovie.height/2);
}

3. Control with Sensors – Light sensor

It’s real name is LDR (light dependant resistor)

A. Digital and analog -> what’s the difference?

B. Electricity – a quick detour
5V, +, +ve, VCC, etc
0V, -, -ve, GND, Ground, etc

C. Reading the sensor to use as the delay time.

Paste this code into a new sketch.

–

import processing.serial.*;
import cc.arduino.*;

Arduino arduino;
int ledPin = 13;
int sensor0 = 0;
int sensor1 = 0;
int sensor2 = 0;

void setup()
{
//println(Arduino.list());
arduino = new Arduino(this, Arduino.list()[0], 57600);
arduino.pinMode(ledPin, Arduino.OUTPUT);
}

void draw()
{
sensor0 = arduino.analogRead(0);
sensor1 = arduino.analogRead(1);
sensor2 = arduino.analogRead(2);
println(“Sensor0 ” + sensor0);
println(“Sensor1 ” + sensor1);
println(“Sensor2 ” + sensor2);
arduino.digitalWrite(ledPin, 255);
delay(sensor2);
arduino.digitalWrite(ledPin, 0);
delay(sensor2);
}

2. Firmata

Get this connected to processing

a. Use the firmata library at http://www.arduino.cc/playground/Interfacing/Processing.

b. download the zip file [http://www.arduino.cc/playground/uploads/Interfacing/processing-arduino.zip] and extract it into processing/libaries

c. If the folder doesn’t exist just create it.

Now Processing knows how to talk to arduino, now it’s time to let the arduino know how to talk back to processing.

Arduino, meet my friend Processing

a. Open Arduino and load File->Examples -> Firmata -> StandardFirmata

This slightly more complex program teaches Arduino to listen out for the things that Processing will say to it.

b. Be sure to upload the sketch to your board before moving on.

Blinking in processing

d. Paste this code intoa new Processing sketch

import processing.serial.*;
import cc.arduino.*;

Arduino arduino;
int ledPin = 13;

void setup()
{
//println(Arduino.list());
arduino = new Arduino(this, Arduino.list()[0], 57600);
arduino.pinMode(ledPin, Arduino.OUTPUT);
}

void draw()

{

arduino.digitalWrite(ledPin, Arduino.HIGH);
delay(1000);
arduino.digitalWrite(ledPin, Arduino.LOW);
delay(1000);
}

—–

1. Blink.

Introduce the arduino, check http://arduino.cc
a. refs and resources:

Camera

-        AR Scratching, Todd Vanderlin, http://toddvanderlin.com/ar-scratching

-        Eye writer, Zach Lieberman http://www.eyewriter.org/

-        Shadow Monsters, Phillip Worthington, http://www.worthersoriginal.com/viki/#page=shadowmonsters

-        IO Brush, Kimiko Ryokai, http://web.media.mit.edu/~kimiko/iobrush

Touch

-        Felt Resistor http://thomas-gerhardt.com/itp/FeltResistor/

-        Tuned Stairs, La Centre Pompidou (2006) http://www.plankman.com/projects/tuned_stairs/

-        Set in stone, Ithai Benjamin and Vikram Tank, http://setinstone.wordpress.com/

Wearable

-        Turn Signal Biking Jacket, Leah Buechley, http://web.media.mit.edu/~leah/LilyPad/build/turn_signal_jacket.html

-        Skinput, Chris Harrison, http://www.chrisharrison.net/projects/skinput/

Motors

-        Waves of Leaves,Soyoung Park, http://www.shine-sy.com/wavesofleaves/

-        Wooden Mirror, Daniel Rozin, http://smoothware.com/danny/woodenmirror.html

Ambient & Environmental

-        Botanicalls, http://botanicalls.com

-        Cousteau, http://www.arjodesign.com/Cousteau.html

-        Loca, Drew Hemment, http://www.loca-lab.org/background.html

b. Run the program Arduino
c. type out blink
Looks very similar to processing:

int led =  13;

void setup()   {
pinMode(led, OUTPUT);
}

void loop() {
digitalWrite(led, HIGH);
delay(1000);
digitalWrite(led, LOW);
delay(1000);
}

Getting on with Tangible interaction design sketching is easy with Arduino and Processing.