let alpha = 255;

let left = 0;

let right = 0;

let velocity;

let gravity;

let position;

let acceleration;

let wind;

let drag = 0.99;

let mass = 80;

let state = 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(250, 200, 152);

​

  if (!serialActive) {

    print("Press Space Bar to select Serial Port");

  } else {

    if (state == 1) {

      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;

      }

​

      if (position.y >= height - mass / 2 - 5) {

        left = 1;

      } else {

        left = 0;

      }

​

      wind.x = map(rVal, 0, 1023, -1, 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 == " ") {

    setUpSerial();

  }

​

  if (keyCode == UP_ARROW) {

    mass = random(15, 80);

    position.y = -mass;

    velocity.mult(0);

  }

​

  if (keyCode == DOWN_ARROW) {

    if (state == 0) {

      state = 1;

    } else {

      state = 0;

    }

  }

}

​

// This function will be called by the web-serial library

// with each new *line* of data. The serial library reads

// the data until the newline and then gives it to us through

// this callback function

function readSerial(data) {

  ////////////////////////////////////

  //READ FROM ARDUINO HERE

  ////////////////////////////////////

​

  if (data != null) {

    // make sure there is actually a message

    // split the message

    let fromArduino = split(trim(data), ",");

    // if the right length, then proceed

    if (fromArduino.length == 2) {

      // only store values here

      // do everything with those values in the main draw loop

​

      // We take the string we get from Arduino and explicitly

      // convert it to a number by using int()

      // e.g. "103" becomes 103

      rVal = int(fromArduino[0]);

      alpha = int(fromArduino[1]);

    }

​

    //////////////////////////////////

    //SEND TO ARDUINO HERE (handshake)

    //////////////////////////////////

    let sendToArduino = left + "," + right + "\n";

    writeSerial(sendToArduino);

  }

}

​