Programming

Description

Image zoom is controlled with the help of a potentiometer, to make the zooming process more intutive and natural.

Components Used

Arduino board

1 resistor

1 potentiometer

Arduino Code

/*
* one pot fades one led
* modified version of AnalogInput
* by DojoDave <http://www.0j0.org>
* http://www.arduino.cc/en/Tutorial/AnalogInput
*/
int potPin = 0; // select the input pin for the potentiometer
int ledPin = 13; // select the pin for the LED
int val = 0; // variable to store the value coming from the sensor
void setup() {
Serial.begin(9600);
}
void loop() {
val = analogRead(potPin); // read the value from the sensor, between 0 - 1024
Serial.println(val/4);
delay(100);
// analogWrite(ledPin, val/4); // analogWrite can be between 0-255
}

Processing Code

//Srinivasan Ramaswamy
//Picture Zoomer
import processing.serial.*;

String portname = "COM7";
Serial port;
PImage img;
int w,h,sw,sh;
int counter=0;
int prevVal=0;
// Change this to the portname your Arduino board

String buf="";
int cr = 13; // ASCII return == 13
int lf = 10; // ASCII linefeed == 10

void setup()
{
size(1024,800);
frameRate(30);
// The background image must be the same size as the parameters
// into the size() method. In this program, the size of "cute.jpg"
// is 200 x 200 pixels.
img = loadImage("cute.jpg");
port = new Serial(this, portname, 9600);
}

void draw()
{
image(img,0,0,width,height);
// a = (a + 1)%(width+32);
// stroke(226, 204, 0);
// line(0, a, width, a-26);
// line(0, a-6, width, a-32);
}

void keyPressed() {
if(key=='+') {
width = width + 10;
height = height + 10;
}
if(key=='-') {
width = width - 10;
height = height - 10;
}

// drawImg();
}

void serialEvent(Serial p) {
int c = port.read();
if (c != lf && c != cr) {
buf += char(c);
}
if (c == lf) {
int val = int(buf);
if (counter==0){
int firstVal = val;
}
if (val>prevVal){
w = val%10;
h = val%10;
width = width+w;
height = height+h;
}
else if(val<prevVal){
w = val%10;
h = val%10;

width = width-w;
height = height-h;
}
print("val="+val);
println(" prevVal="+prevVal);
if (val!=prevVal){
prevVal = val;
}
// int x = int(random(0,width));
// int y = int(random(0,height));
// drawball(x,y,val);
buf = "";
// background(40,40,40); // erase screen
}
}

Zoom Out: Picture zoomed out with the use of potentiometer

Zoom In: Picture zoomed in with the use of potentiometer

Mechanical

The FSR is attached to a ball pen to detect when the pen is switched on/off. THe LED will glow when the ball pen is ready to write and it wil get switched off when its lead is inside.

Ball Pen with FSR