New Textiles 2011

I wanted to make a presaure sensors that would give a smooth data to the computer. First I used two kinds of the resistive thread and knited with them on the small knitting mashine. The effect was very good, I was surprised how fast and easy it was to make a sensor. The resistance changed according to strech of the knitted piece. I started to work on a second sensor to compare the effects from difefrent materials. For the second pressure sensor I used felted wool mixed with aluminium yarn and resistive thread. The sensor gives “jumping” data and it is very hard to press, felt become very thick, I used two metal hooks to make a contact points for alighator clips. My last experiment was to use a conductive in and paint. I dyed a two pieces of sponge one using a coper paint mixed with violet dying paint, second with a conductive ink (carbon based). The coper paint was giving much better results at the beginning, but over night it lost some of it’s properties. I sewed in some small pieces of conductive thread to gain a better conductivity, but after my modification the sensor started to work like a on/offswitch. I’ve realized that the sponge had a better conductivity when it was still wet. I put some watter on my dry sensor and it gave some interesting resutlts – according to my graph it looked like  aline on the middle of my screen which means that the data should be exactly in the middle of 1023 range.

Arduino:

void setup() {

// initialize the serial communication:

Serial.begin(9600);

digitalWrite(A0,HIGH);

//  digitalWrite(A1,HIGH);

}

void loop() {

// send the value of analog input 0:

Serial.println(analogRead(A0));

// wait a bit for the analog-to-digital converter

to stabilize after the last reading:

delay(50);

//Serial.println(analogRead(A1));

delay(10);

}

Processing :

import processing.serial.*;Serial myPort;        // The serial portfloat weight = .05;
int xPos = 20; // horizontal position of the graphint lastX, lastY;void setup () {
// set the window size:  size(800, 600);   //smooth the graphics    smooth();  lastX = xPos;  background(0);  // List all the available serial ports  println(Serial.list());  // I know that the first port in the serial list on my mac  // is always my  Arduino, so I open Serial.list()[0].  // Open whatever port is the one you’re using.  myPort = new Serial(this, Serial.list()[0], 9600);  // don’t generate a serialEvent() unless you get a newline character:  myPort.bufferUntil(‘\n’);  // set inital background:    }  void draw () {  // everything happens in the serialEvent()  }
void serialEvent (Serial myPort) {  // get the ASCII string:  String inString = myPort.readStringUntil(‘\n’);
if (inString != null) {    // trim off any whitespace:    inString = trim(inString);    // convert to an int and map to the screen height:    float inByte = float(inString);     inByte = map(inByte, 0, 1023, 0, height);

noStroke();
fill(#FFA500,inByte-10);    ellipseMode(CENTER);    ellipse(xPos,inByte, 20, 20 );

fill(#3366FF,inByte-10);    ellipseMode(CENTER);    ellipse(xPos,height-inByte–, 20, 20 );
stroke(#FFA500,inByte-10);  strokeWeight(.5);  line(0, 300,xPos,inByte-10);  weight = .15;
stroke(#3366FF,inByte-10);  strokeWeight(.5);  line(0, 300,xPos,height-inByte+10);  weight = .15;
}

// at the edge of the screen, go back to the beginning:    if (xPos >= width) {      xPos = 0;      background(0);    }     else {      // increment the horizontal position:      xPos++;    }       }

Demo videos:

01 Strech Sensor

02 Pressure Sensor