Data Visualization using Particle, Firebase and P5js: https://www.youtube.com/watch?v=puBpA1LmGCs

iot.txt

///////////////////////////////////
// PARTICLE / WIRING CODE        //
///////////////////////////////////

int photoResistor = A0;
int power = A5;
int lightValue;

void setup() {
    pinMode(photoResistor,INPUT);
    pinMode(power,OUTPUT);
    digitalWrite(power,HIGH);
}

void loop() {
    lightValue = analogRead(photoResistor);
    Particle.publish("light", String(lightValue));
    delay(2000);
}

///////////////////////////////////
// P5.js code                    //
///////////////////////////////////

// Initialize Firebase
var config = {
    apiKey: "YOURAPIKEY",
    authDomain: "YOURAUTHDOMAIN",
    databaseURL: "YOURDATABASEURL",
    storageBucket: "YOURSTORAGEBUCKET",
    messagingSenderId: "YOURMESSAGINGSENDERID"
};
firebase.initializeApp(config);
var database = firebase.database();

var counter = 0;

function setup() {
    createCanvas(1440, 900);
    background(255);
}

function draw() {
    // do nothing
}

database.ref('light').limitToLast(80).on('child_added', function(snapshot)
{
    var data = snapshot.val();
    var normalizedLight = map(data.light, 0, 800, 0, 255);
    print(normalizedLight);
    
    // draw a graph
    noStroke();
    fill(normalizedLight);
    rect(counter * 5, 0, 5, height);
    
    fill(255);
    ellipse(width/2, height/2, 200, 200);
    
    fill(normalizedLight);
    textSize(72);
    textAlign(CENTER);
    text(data.light, width/2, height/2);
    
    if(counter < 160)
    {    
        counter++;
    } else {
        background(255);
        counter = 0;
    }
    
})