let ballVelocity;

let ballGravity;

let ballPosition;

let ballAcceleration;

let ballWind;

let ballDrag = 0.99;

let ballMass = 50;

​

// Arduino communication variables

let arduinoWindSensorValue = 0;

let arduinoLedOn = 0;

​

function setup() {

createCanvas(400, 400);

ballPosition = createVector(width/2, 0);

ballVelocity = createVector(0,0);

ballAcceleration = createVector(0,0);

ballGravity = createVector(0, 0.5*ballMass);

ballWind = createVector(0,0);

}

​

function draw() {

background(0);

fill(255);

if (!serialActive) {text("Press Space Bar to select Serial Port", width/4, 30); }

else {text("Connected!", 165, 30); }

​

fill("#39FF14");

applyForce(ballWind);

applyForce(ballGravity);

ballVelocity.add(ballAcceleration);

ballVelocity.mult(ballDrag);

ballPosition.add(ballVelocity);

ballAcceleration.mult(0);

ellipse(ballPosition.x,ballPosition.y,ballMass,ballMass);

​

if (ballPosition.y > height-ballMass/2) {

ballVelocity.y *= -0.9; // A little dampening when hitting the bottom

ballPosition.y = height-ballMass/2;

arduinoLedOn = 1; //If the ball makes contact with the ground, the LED will be ON

}

else {arduinoLedOn = 0;} //Else the LED will be OFF

​

//If the arduinoWindSensorValue value from the Arduino that was mapped is greater than 0, then it will move the ball to the right

if(arduinoWindSensorValue > 0) {

ballWind.x = 0.5;

}

​

//Else if the arduinoWindSensorValue value from the Arduino is less than 0, it will move the ball to the left

else if(arduinoWindSensorValue < 0) {

ballWind.x = -0.5;

}

​

//If it's 0, aka no wind, then it will just keep the ball where it is, no wind.

else {

ballWind.x = 0;

}

}

​

function applyForce(force){

// Newton's 2nd law: F = M * A

// or A = F / M

let f = p5.Vector.div(force, ballMass);

ballAcceleration.add(f);

}

​

function keyPressed(){

if (key == "m"){

ballMass=random(15,80);

ballPosition.y=-ballMass;

ballVelocity.mult(0);

}

​

if(key == " ") {

setUpSerial();

}

}

​

function readSerial(data) {

if(data != null) {

//Sends the arduinoLedOn information to the Arduino

let sendToArduino = arduinoLedOn + "\n";

writeSerial(sendToArduino);

//Reads the arduinoWindSensorValue values from the Arduino and maps its value to either -1 or 1 to correspond to wind direction.

arduinoWindSensorValue = map(data, 0, 1023, -1 , 1);

}

}