Description

My original intent was to make squeezing the FSR squeeze a sort of pastey goo on the screen, but all I was able to get was connected bouncing balls. They way it works now is that when you squeeze the back of the origami crane mounted on the breadboard, strings of connected balls begin falling onto the screen. You can use the pot to control their initial direction.

Components

• Pot
• FSR
• LEDs
• Origami crane

Arduino Code

int fsrPin = 0;  // select the input pin for the sensor

int potPin = 1;

int bledPin = 11;    // select the output pin for the LED

int gledPin = 10;

int fsrVal = 0;        // variable to store the value coming from the sensor

int potVal = 0;

void setup() {

  Serial.begin(9600);

}

void loop() {

  fsrVal = analogRead(fsrPin); // read the value from the sensor, 0-1023

  potVal = analogRead(potPin);

  analogWrite(bledPin, fsrVal/4);  // analogWrite (dimming the LED) can be between 0-255

  analogWrite(gledPin, potVal/4);

  Serial.print("f");

  Serial.println(fsrVal/4);       // writing the value to the PC via serial connection

  Serial.print("p");

  Serial.println(potVal/4);       // writing the value to the PC via serial connection  

  delay(50);                   // rest a little...

}

Processing Code

import java.util.Vector;

import processing.serial.*;

String portname = "/dev/tty.usbserial-A4001nLM";

Serial port;

String buf="";

int cr = 13;  // ASCII return   == 13

int lf = 10;  // ASCII linefeed == 10

int cFsrVal = 0;

int pFsrVal = 0;

int cPotVal = 0;

int pPotVal = 0;

char dev; // current device ID from serial ('f' == FSR, 'p' == POT)

int val; // current device value from serial

int numBalls = 12;

float spring = 0.9;

float gravity = 2;

int WINWIDTH = 800;

int WINHEIGHT = 600;

GoopString cGoop;

Vector goops = new Vector();

GoopString iGoop; // for iterating

int i = 0; // iterator

int maxLength = 5;

void setup() {

  size(WINWIDTH, WINHEIGHT);

  // frameRate(10);

  noStroke();

  smooth();

  background(0); // redraw bg?

  port = new Serial(this, portname, 9600);

}

void draw() {

  // draw stuff

  background(#D4EFFD);

  // draw the goop

  print("# of goops: ");

  println(goops.size());

  if (goops.size() > 0) {

    if (frameCount % 20 == 0 && cGoop.balls.size() < maxLength) {

      cGoop.grow();

    }

    for (int j = 0; j < goops.size(); j++) {

      print("Drawing goop #");

      println(j);

      iGoop = (GoopString) goops.get(j);

      iGoop.move();

      iGoop.display();

    }

  }

}

void keyPressed() {

  if (key == ' ') {

    println("Wiping the screen...");

    background(0);

    goops.removeAllElements();

  }

  else {

    makeGoop(40.0);

  }

}

void makeGoop(float din) {

  color tClr = color(random(255), random(255), random(255));

  goops.addElement(new GoopString(width / 2, 0, cPotVal, 0.0, din, tClr));

  cGoop = (GoopString) goops.lastElement();

}

// called whenever serial data arrives

void serialEvent(Serial p) {

  int c = port.read();

  if (c != lf && c != cr) {

    buf += char(c);

  }

  if (c == lf) {

    dev = buf.charAt(0);

    val = int(buf.substring(1));

    println("dev="+dev+", val="+val);

    if (dev == 'f') {

      pFsrVal = cFsrVal;

      cFsrVal = val;

      if (cFsrVal > 5) {

        makeGoop(cFsrVal);

      }

    }

    else if (dev == 'p') {

      pPotVal = cPotVal;

      cPotVal = (int) (val / 6.375 - 20); // get pot val in -20 to 20 range

    }

    buf = "";

  }

}

// roughly adapted from the Chains example

class GoopString {

  float x, y;

  float diameter;

  float vx, vy;

  color clr;

  Vector balls = new Vector();

  Ball cBall; // current ball in a loop

  Ball pBall; // prev ball in a loop

  GoopString(float xin, float yin, float vxin, float vyin, float din) {

    x = xin;

    y = yin;

    vx = vxin;

    vy = vyin;

    diameter = din;

    clr = #000000;

    balls.addElement(new Ball(xin, yin, vxin, vyin, din, clr));

  }

  GoopString(float xin, float yin, float vxin, float vyin, float din, color clrin) {

    x = xin;

    y = yin;

    vx = vxin;

    vy = vyin;

    diameter = din;

    clr = clrin;

    balls.addElement(new Ball(xin, yin, vxin, vyin, din, clr));

  }

  // add a new node onto the GoopString

  void grow() {

    cBall = new Ball(x, y, vx, vy, diameter);

    balls.addElement(cBall);

  }

  void move() {

    for (i = 0; i < balls.size(); i++) {

      cBall = (Ball) balls.get(i);

      cBall.move();

    }

  }

  void display() {

    for (i = 0; i < balls.size(); i++) {

      cBall = (Ball) balls.get(i);

      cBall.display();

      if (i > 0) {

        stroke(clr);

        strokeWeight(diameter);

        pBall = (Ball) balls.get(i-1);

        line(cBall.x, cBall.y, pBall.x, pBall.y);

      }

    }

  }

}

// Ball class adapted from the BouncyBubbles example

class Ball {

  float x, y;

  float diameter;

  float vx = 0;

  float vy = 0;

  color clr;

  Ball(float xin, float yin, float vxin, float vyin, float din) {

    x = xin;

    y = yin;

    diameter = din;

    vx = vxin;

    vy = vyin;

    clr = #ffffff;

  }

  Ball(float xin, float yin, float vxin, float vyin, float din, color clrin) {

    x = xin;

    y = yin;

    diameter = din;

    vx = vxin;

    vy = vyin;

    clr = clrin;

  }

  void move() {

    //vx *= 0.999;

    vy += gravity;

    x += vx;

    y += vy;

    if (x + diameter/2 > width) {

      x = width - diameter/2;

      vx += -0.9; 

    }

    else if (x - diameter/2 < 0) {

      x = diameter/2;

      vx *= -0.9;

    }

    if (y + diameter/2 > height) {

      y = height - diameter/2;

      vy *= -spring; 

    } 

    else if (y - diameter/2 < 0) {

      y = diameter/2;

      vy *= -spring;

    }

  }

  void display() {

    noStroke();

    fill(clr);

    ellipse(x, y, diameter, diameter);

  }

}

Pictures

ThirdSqueeze: Board & Screen

ThirdSqueeze: More of the Board