5. E-textiles

Research

Some concepts I want to remember from Liza's lecture, since it's my first time working with them:

Voltage: refers to the differnece in potentia electrical energy measured between 2 points in a circuit. All voltage must be used (2v leftover max) so you need to add more LEDS or resistance

Current: ammount of electricity that passes through the circuit

Resistance: uses the leftover voltage, a resistor determines how much electricy (current) flows trougb components. Resistors dont have + -

Forward Voltage: Voltage that a component uses. LED forward voltage depends on the color.

• White 3.3V
• blue leds 3.2V
• red leds 1.95V
• yellow 2.0V
• pink 2.9 V

Conductive materials:

• Fabrics:
• Threads and yarns
• Inks & Tapes:

References & Inspiration

For centuries, humans have been relying on the observation of the sky for physical, cronological and spiritual guidance. Although I do not necessarily believe in the zodiac or divination (astrology), I do find astronomy a very fascinating science and in general, the artwork related to celestial bodies to be beautiful

Sidney Hall / Adam Cuerden - United States Library of Congress's Prints and Photographs division

When looking at the circuit boards and traces, I immediately thought of stars and constellations, how they connect and form shapes among them. I decided to use the constellation of my zodiac sign Pisces ♓︎ for this assigment. The name comes from the latin meaning, fishes.

The idea sounded simple enough:add LEDs where the stars would be and have a night sky that could light up. I did not look for inspiration for this, but after I completed my work I realized this was not the first time someone came up with this idea. Here's some work I found that uses the same concept:

Taurus Constellation by Gimarcon Bordado

@shebuildsrobots Make e-textiles with me! #sewtok #girlswhocode #programming @girlswhocode ♬ Rainy Days X Animal Crossing - Vibes

@shemakesrobots

Our instructor's Diane Wakim also embroidered a constellation on a sweatshirt. Her design features 5 LEDs and a moon. Her process can be found on her page

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Tools & Materials

• Arduino UNO
• Arduino IDE
• Paragona Wiremesh
• Madeira HC40 Silver Pleated Conductive Thread
• Alligator Clips
• Jumper Wires

• Emboridery machine Brother PR670E
• Breadboard

Some of th materials we used at the lab to learn

Process and workflow

After the lecture and tutorial on Wednesday, I was still a bit lost and overwhelmed. It was a lot of new information to me. Our instructor at the lab, Capucine helped us go through a slower step by step example from Nuria's tutorial. After that, I was able to replicate the process myself and create my inputs.

• Fabricademy 2021-22 Tutorial Basic Electronics
• Fabricademy 2021-22 Tutorial Intro to Arduino by Emma Pareschi

We worked on quick prototypes for:

Digital Switch (button) - a button is a break in the circuit. Since the circuit is not complete, no electricity can go through. To achieve this, we followed the sandwich method. The neoprene acts as a cushion to keep the conductive material from touching therefore, when applying pressure in the cutout part it acts as a button.

On this diagram, the blue felt is decorative and will encapsulate the button

• It's important to consider that the 2 layers of copper mesh or conductive material should not touch at any point other than the cut out hole when pressed.
• I added 2 pieces of conductive thread to connect to the voltimeter here.

via GIPHY

Arduino Digital Button code by Emma Parescht

/*Emma Parescht,
* this skecth is a modification of the example button!!
*/
int digital_sensor_pin = 8;
int digital_sensor_value = 0;
int led_pin = 3; //change the pin of the Led

void setup (){
// put your setup code here, to run once:
pinMode(digital_sensor_pin, INPUT);
Serial.begin(9600);
// initialize digital pin LED_BUILTIN as an output.
pinMode(led_pin, OUTPUT);
//change the pin, where the sensor is connected?
}
void loop() {
// put your main code here, to run repeatedly:
digital_sensor_value = digitalRead(digital_sensor_pin);
// check if the pushbutton is pressed. If it is, the buttonState is HIGH:
if(digital_sensor_value == HIGH){
// turn LED on:
digitalWrite(led_pin, HIGH);
} else {
// turn LED off:
digitalWrite(led_pin, LOW); // turn the LED off by making the voltage LOW
}
}

Arduino code - Fade

/*
  Fade

  This example shows how to fade an LED on pin 9 using the analogWrite()
  function.

  The analogWrite() function uses PWM, so if you want to change the pin you're
  using, be sure to use another PWM capable pin. On most Arduino, the PWM pins
  are identified with a "~" sign, like ~3, ~5, ~6, ~9, ~10 and ~11.

  This example code is in the public domain.

  https://docs.arduino.cc/built-in-examples/basics/Fade/
*/

int led = 3;         // the PWM pin the LED is attached to
int brightness = 0;  // how bright the LED is
int fadeAmount = 5;  // how many points to fade the LED by

// the setup routine runs once when you press reset:
void setup() {
  // declare pin 9 to be an output:
  pinMode(led, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  // set the brightness of pin 9:
  analogWrite(led, brightness);

  // change the brightness for next time through the loop:
  brightness = brightness + fadeAmount;

  // reverse the direction of the fading at the ends of the fade:
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount;
  }
  // wait for 30 milliseconds to see the dimming effect
  delay(30);
}

Arduino Code - Blink

int pin_led=3;

void setup() {
  // put your setup code here, to run once:
pinMode(pin_led,OUTPUT); //define the pin 3 as output
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(pin_led,HIGH);  //turn on the light (5V)
  delay(100);   //wait 1sec
  digitalWrite(pin_led,LOW); //turn off the light (0V/ground)
  delay (100); //wait 1sec
  }

Analog sensor - An interface (input) that allows variance in resistance due to the nature of the structure or the materials. We used velostat, a carbon impregnated film which adds resistance to the circuit that is pressure sensitive.

• The bigger the pressing surfce, the more room to play around with the sensitivity of the velostat. Tape the conductive thread along the material.

int analog_sensor_pin = A0;
int analog_sensor_value = 0;

// the setup routine runs once when you press reset:
void setup() {
  // adding the button as input
  pinMode(analog_sensor_pin, INPUT);
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);

}

// the loop routine runs over and over again forever:
void loop() {

  analog_sensor_value = analogRead(analog_sensor_pin);  // read the input pin, sensor
  // print out the state of the button:
  Serial.println(analog_sensor_value); 
  delay(100);  // delay in between reads for stability

}

/*arduino {#code4} We use this sketch to connect a LED and read a range of values

// analog pin 2 has a pushbutton attached to it. Give it a name: int analog_sensor_pin = A0; int analog_sensor_value = 0; int led_pin=3;

// the setup routine runs once when you press reset: void setup() { // adding the button as input pinMode(analog_sensor_pin, INPUT); // initialize serial communication at 9600 bits per second: pinMode(led_pin, OUTPUT); Serial.begin(9600);

}

// the loop routine runs over and over again forever: void loop() {

//original range //min: 110 //max: 220 //new range: 0/255

analog_sensor_value = analogRead(analog_sensor_pin); // read the input pin, sensor analog_sensor_value = map(analog_sensor_value, 110, 220, 0, 255); // We need to be precise to see changes in light so map function to change my original range to new range analog_sensor_value = constrain(analog_sensor_value, 0, 255);

analogWrite(led_pin, analog_sensor_value); Serial.println(analog_sensor_value); delay(10); // delay in between reads for stability ```

Design & embroidery

To work on the textile piece, I started created my design on Figma. Initially I had only considered 1 line for the constellation but I added a second one below since we were using the mini LEDs that needed to be sewed in. They need 2 lines so one is the + and one is the -

The idea is that by touching the pisces symbol, the constellation lights up. For this I used conductive thread for the ♓︎ symbol and the stars and line that connects them. The circle frame, "Pisces" title and stars were embroidered using regular thread.

Preparing the file in the embroidery software and the felt in the frame

Quick test of the conductivity of the thread with a battery and LED

• I used a battery pocket on the back. I am using a 3V coin cell battery but ideally I should get a bigger one to get more brightness (3.7v lipo).
• The pisces sign on the front is embroidered with conductive thread so, it tocuhes the battery on the back.
• To get the constellation to light up, I added 2 threads in the back from the battery to the constellation. I did not embroidered these because I did not want them to be visible from the front. It's important that they do not touch each other.