5. E-textiles

Research

Starting this e-textile week has been an exciting journey into the fusion of electronics and textiles. Exploring how conductive materials can be integrated into fabrics has sparked endless creative possibilities. The ability to bring textiles to life with LEDs, sensors, and interactive circuits feels like opening a door to a new realm of innovation in fashion and design. It’s fascinating to see how traditional techniques like knitting, weaving, or embroidery can merge with modern technology to create functional, responsive, and aesthetically captivating pieces. This week has truly broadened my perspective on what textiles can achieve.

Besides reminiscing, I found these projects both inspiring and captivating.

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BASIC ELECTRONIC CIRCUITS

KEY WORDS

Circuit: A complete circular path that electricity flows through.

Current: A flow of charged particles, such as electrons or ions, moving through an electrical conductor or space.

Resistance: A measure of the opposition to current flow in an electrical circuit. Measured in Ohms(Ω).

Trace: A pathway for electricity to flow.

Voltage: THe pressure from an electrical circuit's power source that pushes charged electrons (current) through a conducting loop, enabling them to do work such as illuminating a light.

ELECTRONICAL SYMBOLS AND TERMS

Resister:An electrical device which resists current flow regardless of frequency. Basic unit of measurement is Ohm.

Capacitor: A pair of parallel "plates" separated by an insulator (the dielectric). It stores an electric charge, and tends to pass higher frequencies more readily than low frequencies. Does not pass direct current, and acts as an insulator. Electrically it is the opposite to an inductor. Basic unit of measurement is the Farad, but is typically measured in micro-farads (uF = 1 x 10-6F) or nano-farads (nF - 1 x 10-9 F)

Diode: A semiconductor device that essentially acts as a one-way switch for current. It allows current to flow easily in one direction, but severely restricts current from flowing in the opposite direction.

Transistor: A miniature semiconductor that regulates or controls current or voltage flow in addition amplifying and generating these electrical signals and acting as a switch/gate for them.

Cell: one section of a battery.

Ground: A reference point that carries a voltage of 0V. Voltage measurements are relative measurements.

Fuse: A safety device that operates to provide overcurrent protection of an electrical circuit.

Circuit Breaker: A switch that automatically interrupts the current of an overloaded electric circuit, ground faults, or short circuits.

Inductor: A coil of wire which exhibits a resistance to any change of amplitude or direction of current flow through itself. Inductance is inherent in any conductor, but is "concentrated" by winding into a coil. An inductor tends to pass low frequencies more readily than high frequencies. Electrically it is the opposite of a capacitor. Basic unit of measurement is the Henry (H), in crossover networks it will typically be measured in milli-henrys (mH = 1 x 10-3H) and for RF micro-henrys (uH) are common.

Transformer: A passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. It steps up or steps down voltage.

Relay： A switch that uses electromagnetism to convert small electrical stimuli into larger currents.

Generator: A machine which transforms mechanical energy or magnetic energy into electric energy.

DIGITAL CIRCUIT

Digital Circuit is a circuit where the signal must be one of two discrete levels. It's discontinued and acts like a switch where each level is interpreted as one of two different states for example, on/off, 0/1

ANALOG CIRCUIT

Analog, or linear, circuits typically use only a few components and are thus some of the simplest types of ICs. Generally, analog circuits are connected to devices that collect signals from the environment or send signals back to the environment.

What are the differences between a digital and an analogue circuit?

1. The current and voltage of an analogue circuit are constant over a cycle, whereas in a digital circuit they pulsate and change.

2. Analogue and digital circuits are also carriers of signal changes. Analogue circuits operate by amplifying and reducing the signal in the circuit through the amplification characteristics of the components (e.g. triodes), whereas digital circuits operate by switching the signal (e.g. triodes).

3. In analogue circuits, voltage, current frequency and period are mutually constrained, whereas in digital circuits the change in voltage, current frequency and period in the circuit is discrete.

4. Analogue circuits can operate at high voltages with high currents, whereas digital circuits only operate at low voltages with low currents and low power consumption. to complete or produce a stable control signal.

5. The analog circuit supplies the power to the digital circuit and executes the actuator. The digital circuit, on the other hand, completes the entire circuit operation process through its unique logic operation. Therefore, if we have a clear understanding of the boundaries between digital and analogue circuits in maintenance, we can be more comfortable and convenient.

TYPES OF CIRCUIT CONNECTION

Series circuit

series circuit, any electrically conducting pathway comprising an electric circuit along which the whole current flows through each component. The total current in a series circuit is equal to the current through any resistor in the series

parallel circuit

A parallel circuit is one that has two or more paths for the electricity to flow, the loads are parallel to each other

RESISTOR COLOR CODING

The resistor color code calculator makes it easy to identify and select resistance and tolerance values for 4, 5, and 6 band through hole resistors.

## First Experiment

For my first experiment, I set out to create a straightforward circuit using LEDs, a power supply, and a resistor. The goal was to understand the basic principles of circuit design and how these components interact with one another. I began by gathering all the necessary materials, ensuring I had a variety of LEDs to experiment with different colors and brightness levels. I connected the power supply, carefully choosing the voltage to match the requirements of the LEDs to avoid any potential damage.

TOOLS

1 LED

2 Batteries

3 Resistance

4 Jumper wires

5 Breadboard

6 Yarn

7 Crochet

8 Arduino IDE

9 Push button

10 Arduino nano board

Reading the analog sensor with Arduino

This part was a bit confusing to me, I recently experimented with controlling five LEDs using a variable resistor, which allowed me to adjust their brightness. The variable resistor acts as a dimmer, varying the amount of current flowing through each LED. As I tweaked the resistor, I could see the brightness levels of the LEDs changing in real-time, giving me a better understanding of how resistance affects electrical circuits. This was an exciting challenge, as it allowed me to explore both the hardware and the principles of electronics, adding more complexity to my previous experience with basic circuits.

A variable resistor, also known as a potentiometer or rheostat, is an electrical component that allows you to adjust the resistance in a circuit manually. By changing the resistance, it controls the flow of electrical current, which can be used to adjust the brightness of LEDs, the speed of motors, or the volume in audio devices. In essence, a variable resistor provides the flexibility to fine-tune the output of electronic devices by altering the amount of current passing through them without needing to change the circuit design. here is some codes I used to bink this LEDs

and circuit used to blink 5 LED with variable resistor

After experimenting with blinking LEDs, I integrated the circuit onto a textile to create a more interactive, tactile experience. The process involved challenges with connectivity and flexibility, but seeing the LEDs blink directly on the fabric brought a new dimension to the piece. This successful test opens up exciting possibilities for future textile-based electronic design

Reading digital sensor Arduino

The DHT11 is a low-cost sensor for measuring temperature (0–50°C) and humidity (20–90%). It’s easy to use, sends digital data, works with 3.3–5.5V, and updates once per second. It’s great for simple projects but has limited accuracy and range

As I tested the sensor, I noticed how responsive it was to changes in the environment, providing real-time data that I could use for various applications. The DHT sensor not only opened up possibilities for monitoring indoor climate conditions but also inspired me to think creatively about how I could integrate this data into larger projects, such as automated climate control systems or data logging for environmental studies. Overall, using the DHT sensor has been an enlightening experience, reinforcing my understanding of digital sensors and their practical applications in technology.

This is a circuit I attempted to create on a breadboard."

another Digital experiment

A device with only two possible statuses—ON or OFF—operates in a binary manner, meaning it can exist in one of two states at any given time. This type of device is commonly used in various applications, such as light switches, basic electronic circuits, and digital systems. When the device is in the ON state, it allows the flow of electricity or the execution of a specific function, while the OFF state interrupts this flow or halts the function. This simplicity makes such devices easy to understand and control, forming the foundational building blocks for more complex systems in electronics and automation.

In this experiment, I focused on creating an interactive setup using LEDs and sensors integrated into a textile. The goal was to develop a system where user interaction would trigger a response from LED. I arranged the LED in a pattern on the fabric

include

// Define DHT sensor type and pin

define DHTPIN 2

define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

// Define LED pin const int LED_PIN = 8;

// Set temperature threshold const float TEMP_THRESHOLD = 25.0;

void setup() { // Initialize LED as output pinMode(LED_PIN, OUTPUT);

// Start the DHT sensor dht.begin();

// Start Serial Monitor Serial.begin(9600); }

void loop() { // Read temperature from DHT11 float temperature = dht.readTemperature();

// Check if the reading is valid if (isnan(temperature)) { Serial.println("Failed to read from DHT sensor!"); return; }

// Print temperature to Serial Monitor Serial.print("Temperature: "); Serial.print(temperature); Serial.println(" °C");

// Control the LED based on temperature if (temperature > TEMP_THRESHOLD) { digitalWrite(LED_PIN, HIGH); // Turn LED ON } else { digitalWrite(LED_PIN, LOW); // Turn LED OFF }

// Wait for 2 seconds before the next reading delay(2000); }

Tutorials

1 Ardunio Built-in Examples Collection of tutorials to learn the basics of Arduino. All code examples are available text

2 E-Textile Swatchbook text

3 E-Textiles Fabricademy text

4 Electronics and Sensors text