let gravity;

let position;

let acceleration;

let wind;

let drag = 0.99;

let mass = 50;

​

let ard_wind = 1; //initializing the wind speed 

let bit;

​

function setup() {

  createCanvas(640, 360);

  position = createVector(width / 2, 0);

  velocity = createVector(0, 0);

  acceleration = createVector(0, 0);

  gravity = createVector(0, 0.5 * mass);

  wind = createVector(0, 0);

  bit = 0; //initializing the value for the LED

}

​

function draw() {

  background(255);

​

  if (!serialActive) {

    text("Press Space Bar to select Serial Port", 20, 30);

  } else {

    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; 

      bit = 1; //lighting up the LED upon collision with "the ground"

    } else {

      bit = 0; //turning off the LED when the ball is not touching "ground"

    }

  }

}

​

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 (keyCode == LEFT_ARROW) {

    wind.x = ard_wind * -1; //when left arrow is pressed, the velocity of the wind attains a negative value and the ball moves to the left 

  }

  if (keyCode == RIGHT_ARROW) {

    wind.x = ard_wind; //when the right arrow is pressed, the velocity of the wind attains a positive value and the ball moves to the right 

  }

  if (keyCode == DOWN_ARROW) {

    mass = random(15, 80);

    position.y = -mass;

    velocity.mult(0);

  }

  if (key == " ") {

    // important to have in order to start the serial connection!!

    setUpSerial();

  }

}

​

function readSerial(data) {

  if (data != null) {

    let sen = bit + "\n";

    writeSerial(sen); //sending the values to light up or turn off the LED

    ard_wind = map(data, 0, 300, 0, 10); // mapping the data received from arduino to a sensible range for the wind velocity 

    console.log(ard_wind);    

  }

}