Part 1: Control an LED using a soft sensor and Arduino.

Part 2: Build a circuit with one constructed sensor (variable resistor), your Arduino, and 3 (or more) LEDs or an RGB LED.

Watch in action here; still images below.

 (the setup)

 (full glass on sensor triggers all three LEDs)

 (playing with light, water, and glass)

Summary: Arduino reads the analog input from a constructed pressure sensor, controlled for example by pouring water into a jar over the sensor pad. Based on the input, the Arduino controls three LEDs: the more pressure, the more lights turn on.

Pressure sensor materials: Velostat, conductive tape, cork, LEDs.

Code: https://github.com/annagarbier/annagarbier.github.io/blob/master/work/courses/2018/fall/computational_craft/resources/code/assignment_6.ino

Code snippet:

```
// This function determines the LED pins' output (HIGH or LOW)
// based on the sensor pin's input (held in the variable "average").
void displayLights() {
if (average > 200) {
digitalWrite(ledA, HIGH);
digitalWrite(ledB, HIGH);
digitalWrite(ledC, HIGH);
} else if (average > 150) {
digitalWrite(ledA, HIGH);
digitalWrite(ledB, HIGH);
digitalWrite(ledC, LOW);
} else if (average > 100) {
digitalWrite(ledA, HIGH);
digitalWrite(ledB, LOW);
digitalWrite(ledC, LOW);
} else {
digitalWrite(ledA, LOW);
digitalWrite(ledB, LOW);
digitalWrite(ledC, LOW);
}
}
```

Part 3: Document midterm ideas.

I’d like to create transparent modular blocks, each containing a piece of a circuit: e.g. one might contain a 3v battery, another a resistor, another an LED, and others just connecting components. A user would be able to play with the blocks by connecting them in 3d space; complete a circuit with the blocks, and the blocks with the LED shines.

The intention is to build something simple, playful, and educational.

 (early ideation on paper)

 (prototyping)

1. Connect one of a soft switch to your Arduino. Use it to control an LED.

I decided to try out Lily tiny ( ATtiny-85). It quite tricky to set up and to control as desired. I got to control the LED with my soft switch.

2. Build a circuit with one constructed sensor (variable resistor), your Arduino, and 3 (or more) LEDs or an RGB LED. 

I tried with the Lily tiny but I didn’t manage to control the analog input properly. So I switched back to the Arduino UNO. I created a switch with copper fabric and Velastat that allows me to control the Leds easily.

I wanted to create a stretchy switch with a french knitter, but I could use conductive yarn, so I used regular yarn.

It looks nice I could use it in the future.

Midterm proposal

I’m planning on creating an interactive scarf. A very handy piece for those cold winters to measure the intensity of those persistent sneezes.

I have to figure out some details, such as how to control the signal with the lily tiny or how to power the system without wires.

I used a knitting loom and the conductive yarn to make this soft sensor. The output of the sensor varies according to the shape of the knitting piece. If I fold the sensor, the output will decrease. So I wrote the code that if the output of the soft sensor reaches a certain number, the LED will be turned on.

This is a fabric flower made by felt and an RGB LED. I used a photoresistance as the variable to change the color of the LED. Here is the screenshot of the code:

Midterm:

I am going to combine the midterm assignments from New Arcade and Computational Craft. This project will be game design garments that two players can wear and fight each other. The inspiration comes from a traditional Chinese game — Judose. It is a game played by standing on one leg and grasping the other, it is a physically competitive game with one simple rule, to knock your opponent over. The original version of the game is quite violent. What I am going to do is adding conductive fabric and LED instructions to the kneecap. Attacking your competitor on the particular area will cause your competitor to lose his points. The player who loses all the points first is the loser, and the other one is the winner.

LED CONTROL VIA BUTTON

Thanks to Dario for the soft switch. It works perfectly fine. I like how squishy of the switch. The circuit is pretty simple. I use “INPUT_PULLUP” for the switch. It’s a quick tip for all buttons 😀

LED CONTROL VIA BUTTON CODE

/*
Button

The circuit:
– LED attached from pin 13 to ground
– pushbutton attached to pin 2 from +5V
– 10K resistor attached to pin 2 from ground

– Note: on most Arduinos there is already an LED on the board
attached to pin 13.

created 2005
by DojoDave <http://www.0j0.org>
modified 30 Aug 2011
by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/Button
*/

// constants won’t change. They’re used here to set pin numbers:
const int buttonPin = 8; // the number of the pushbutton pin
const int ledPin = 7; // the number of the LED pin

// variables will change:
int buttonState = 0; // variable for reading the pushbutton status

void setup() {
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);

// check if the pushbutton is pressed. If it is, the buttonState is HIGH:
if (buttonState == HIGH) {
// turn LED on:
digitalWrite(ledPin, LOW);
} else {
// turn LED off:
digitalWrite(ledPin, HIGH);
}
}

MARCH OF LEDs

It is tricky to make each of them light up when I press my switch. I have to make the specific states for them to light up in order. It’s pretty fun and cute with 3 LEDs with Red, Yellow and Green.

MARCH OF LEDs CODE

/*
Button

Turns on and off a light emitting diode(LED) connected to digital pin 13,
when pressing a pushbutton attached to pin 2.

The circuit:
– LED attached from pin 13 to ground
– pushbutton attached to pin 2 from +5V
– 10K resistor attached to pin 2 from ground

– Note: on most Arduinos there is already an LED on the board
attached to pin 13.

created 2005
by DojoDave <http://www.0j0.org>
modified 30 Aug 2011
by Tom Igoe

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/Button
*/

// constants won’t change. They’re used here to set pin numbers:
const int buttonPin = 8; // the number of the pushbutton pin
const int ledPin = 7; // the number of the LED pin

bool startCapture;
float Timer = 0;
float Duration = 10000;
int State = 0;

bool Pressed;
bool Added;

// variables will change:
int buttonState = 0; // variable for reading the pushbutton status

void setup() {
Serial.begin(9600);
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
pinMode(6, OUTPUT);
pinMode(5, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);

Serial.println(State);

if (!Pressed && buttonState == 0)
{
Pressed = true;
}

if (Pressed && buttonState == 1)
{
Pressed = false;
Added = false;
}

if (Pressed && !Added)
{
State++;
Added = true;
}

if (State == 1)
{
digitalWrite(7, HIGH);
digitalWrite(6, LOW);
digitalWrite(5, LOW);
}

if (State == 2)
{
digitalWrite(7, HIGH);
digitalWrite(6, HIGH);
}

if (State == 3)
{
digitalWrite(7, HIGH);
digitalWrite(6, HIGH);
digitalWrite(5, HIGH);
}

if (State > 3)
{
digitalWrite(7, LOW);
digitalWrite(6, LOW);
digitalWrite(5, LOW);
State = 0;
}

}

MIDTERM IDEA

I want to make one big squishy doll that can emit some lights through its eyes by dragging the tail. It could be really cute! The technique I use is going to be wool felting.