let drag = 0.99, mass = 50, hasBounced = false;

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);

    textAlign(CENTER);

    textSize(18);

}

function draw() {

    background(255);

    applyForce(wind);

    applyForce(gravity);

    velocity.add(acceleration);

    velocity.mult(drag);

    position.add(velocity);

    acceleration.mult(0);

    fill(hasBounced ? 'green' : 'white')

    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;

        if (!hasBounced && abs(velocity.y) > 1) {

            hasBounced = true;

            setTimeout(() => hasBounced = false, 100); // Set hasBounced to false after 0.1 s

        }

    }  

    if (!serialActive) {

        background(8);

        fill('white');

        text("Press c to connect to the Arduino", width/2, height/2)

    }

}

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.set(width/2, -mass);

        velocity.mult(0);

        gravity.y = 0.5*mass;

        wind.mult(0);

    } else if (key == 'c') {

        setUpSerial(); // Start the serial connection

    }

}

function readSerial(data) {

    if (data != null) { // Ensure there's actually data

        wind.x = map(int(data), 0, 1023, -2, 2);

        writeSerial((hasBounced ? 1 : 0) + '\n');

    }

}

​