Week 11 – Exercises on Arduino + p5.js – Introduction to Interactive Media

Task 1:
Light sensor controls ellipse on p5.js
https://drive.google.com/file/d/1LG16uZcffBsWkmddW0rGVTF8lVujMUjo/view?usp=sharing

int lightPin = A0;
void setup() {
Serial.begin(9600);
pinMode(lightPin, INPUT);
}
void loop() {
int sensorValue = analogRead(A0);
Serial.println(sensorValue);
delay(5);
}

let address = 0;

function setup() {
  createCanvas(600, 600);
  noFill();
}

function draw() {
  background("purple");
  stroke("white");

  // Convert the incoming sensor reading (0–1023) into a horizontal screen position
  ellipse(map(address, 0, 1023, 0, width), height / 2, 100, 100);

  if (!serialActive) {
    // Show a connection screen while serial communication hasn’t started yet
    background("rgb(70,9,70)");
    stroke("white");
    textSize(50);
    text("Press Space Bar to select Serial Port", 20, 30, width - 30, 200);
  }
}

function keyPressed() {
  // When the space bar is pressed, begin the setup process for the serial port
  if (key == " ") setUpSerial();
}

function readSerial(data) {
  // If valid data arrives from the Arduino, save it for use in draw()
  if (data != null) {
    address = int(data);
  }
}

Task 2:
Controlling brightness of LED on p5.js using mouseX position
https://drive.google.com/file/d/1F5u96LDEvKJTtBuD6cbVIIlCcqiFUnyZ/view?usp=sharing

// Holds the brightness value we will send to the Arduino
let brightness = 0;

// Stores any data received back from Arduino (not used, but required)
let latestData = "";

function setup() {
  // Create the canvas where visual feedback will appear
  createCanvas(600, 400);
  noStroke();
}

function draw() {
  // Clear the screen each frame with a black background
  background(0);

  // Convert trackpad/mouse X position (0 → width) into brightness (0 → 255)
  brightness = int(map(mouseX, 0, width, 0, 255));

  // Draw a rectangle whose fill intensity matches the brightness value
  fill(brightness);
  rect(0, 0, width, height);

  // If a serial port is active, send the brightness value to the Arduino
  if (serialActive) {
    writeSerial(brightness + "\n"); // "\n" ensures Arduino reads full numbers
  }

  // If serial is NOT open, show instructions to the user
  if (!serialActive) {
    background("purple");
    fill("white");
    textSize(28);
    text("Press SPACE to choose Serial Port", 20, 40);
  }
}

function keyPressed() {
  // Press SPACE to open the Web Serial port selection dialog
  if (key === " ") {
    setUpSerial();
  }
}

// This function is REQUIRED by p5.webserial
// It receives data sent from Arduino (even if unused)
function readSerial(data) {
  if (data) latestData = data;
}

// Sends data to Arduino IF the writer is available
function writeSerial(value) {
  if (writer) {
    writer.write(value);
  }
}

int ledPin = 9;
int brightness = 0;

void setup() {
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);
}

void loop() {
  if (Serial.available() > 0) {
    brightness = Serial.parseInt();
    brightness = constrain(brightness, 0, 255);
  }

  analogWrite(ledPin, brightness);
}

Task 3:
Potentiometer to control the direction of the wind and LED light when when ball bounces
https://drive.google.com/file/d/1x8fewdACiGBJ0Qv7vc6tiyZ5ukW19EtK/view?usp=sharing

int LED = 9;
int POT = A0;


void setup() {
Serial.begin(9600);
pinMode(LED, OUTPUT);


// Test the LED
digitalWrite(LED, HIGH);
delay(500);
digitalWrite(LED, LOW);
}


void loop() {
int p_value = analogRead(POT); // read from the potentiometer
int move = map(p_value, 0, 1023, -1, 2); // map the value to -1, 0, and 1
Serial.println(move);


if (Serial.available() > 0) {
// read from p5.js
int touch = Serial.parseInt();
// set the LED command
if (touch == 1) {
digitalWrite(LED, HIGH);
} else {
digitalWrite(LED, LOW);
}
}
}

let velocity;
let gravity;
let position;
let acceleration;
let wind;
let drag = 0.99;
let mass = 50;
let on = 0;

function setup() {
  createCanvas(640, 360);
  //noFill();
  position = createVector(width/2, 0);
  velocity = createVector(0,0);
  acceleration = createVector(0,0);
  gravity = createVector(0, 0.5*mass);
  wind = createVector(0,0);
}

function draw() {
  background(255);
  
  if (!serialActive) {
    text("Click on the Screen to select Serial Port", 20, 30);
  } else {
    text("Connected", 20, 30);
  }
  
  applyForce(wind);
  applyForce(gravity);
  velocity.add(acceleration);
  velocity.mult(drag);
  position.add(velocity);
  acceleration.mult(0);
  ellipse(position.x,position.y,mass,mass);
  if (position.y > height-mass/2) {
      velocity.y *= -0.9;  // A little dampening when hitting the bottom
      position.y = height-mass/2;
  }
  // turn on the LED only when it's on the ground or hits the ground
  if(position.y == height-mass/2){ 
    on = 0;
  }else{
    on = 1;
  }
}
function applyForce(force){
  // Newton's 2nd law: F = M * A
  // or A = F / M
  let f = p5.Vector.div(force, mass);
  acceleration.add(f);
}
function keyPressed(){
  if (key==' '){
    mass=random(15, 80);
    position.y=-mass;
    velocity.mult(0);
  }
}
function mousePressed() {
    setUpSerial();
}
function readSerial(data) {
  if (data != null) {
    // make sure there is actually a message
    // split the message
    wind.x = data;
    //////////////////////////////////
    //SEND TO ARDUINO HERE (handshake)
    //////////////////////////////////
    let sendToArduino = on + "\n";
    writeSerial(sendToArduino);
  }
}

Reflection
I generally liked on working and understanding underlying concepts behind how to the Arduino and p5.js sketches work together. I already see my progress being able to understand how pins work and how to connect each sensor properly. I wanted to avoid using distance sensor because I used it for the last project. We worked together with Aizhan, and used AI a bit for the third task to helps us understand how gravity and velocity worked, and it helped us come up with a code to connect potentiometer as a wind.

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