For this week’s assignment, we had to make a web dashboard for controlling a Philips Hue bulb. I was pretty stretched for time this week so I decided to keep things simple and learn the basics. Going through the tutorial was pretty self-explanatory and the code on github was pretty logical. However, I tripped up with the call-backs and it was quite confusing for me to understand. Thankfully, I read through Timothy and Atharva’s blog and their call-backs made sense to me. I created a basic UI where the Hue can be controlled by changing it’s Hue, Saturation and Brightness values through sliders and also gave the users the option to turn it on and off. I was also changing the background of the webpage to match the color of the Hue bulb.

Screenshot 2019-02-12 04.26.39.png

I was looking at changing the color of the text to a complementary color based on the currently selected value but did not find any easy way to convert HSB values to its complementary colors. Also, I had thought of an ambient mode where the digits of HH:MM:SS are converted into a RGB hex value which is then transmitted to the hue. Again, I tripped up because I could not find a reliable way to do this. Passing RGB to HSL did not match the colors. So my top questions for this week would be:

1) How do you calculate the complementary HSB value of a color through code?

2) How do you convert a rgb color to a HSB color?

Currently listening: A whiter shade of pale - Procol Harum

References used:


//IP address of Philips Hue
let IPHub = '';
let userName = 'g12MalhwYs2DUmfQhW-GYJEzwYsV3mYxiKJLXuxb'; // My user name as per the hue developer API
let url;

let gotham;

//Variables for display of controls and labels
let checkBox;
let hueSlide;
let hueText;
let satSlide;
let satText;
let brightSlide;
let brightText;

//Variables for controlling the philips bulb and its color
let lightNum = 1;
let hueVal = 32767;
let satVal = 127;
let brightVal = 127;

//Loading fonts
function preload() {
  gotham = loadFont('assets/Gotham Book.otf');

function setup() {

  //Create canvas
  canvas = createCanvas(windowWidth, windowHeight);
  canvas.background(hueVal, satVal, brightVal);

  //Declare Hue URL
  url = "http://" + IPHub + "/api" + userName;

  //Position ON/OFF checkbox
  checkBox = createCheckbox(' IS ON/OFF', false);
  checkBox.position(canvas.width / 2 - 90, 200);

  //Position Sliders for color control
  hueSlide = createSlider(0, 65535, 32767, 100);
  hueSlide.position(canvas.width / 2 - 225, 400);'rotate', 90);

  satSlide = createSlider(0, 254, 127, 1);
  satSlide.position(canvas.width / 2 - 100, 400);'rotate', 90);

  brightSlide = createSlider(1, 255, 127, 1);
  brightSlide.position(canvas.width / 2 + 25, 400);'rotate', 90);

  //Position button for 'Ambient Mode'
  button = createButton('Ambient mode');
  button.position(canvas.width / 2 - 85, 600);


function draw() {


  if (hueSlide.value() != hueVal || satSlide.value() != satVal || brightSlide.value() != brightVal) {

    //Change color

    //Capture slider value
    hueVal = hueSlide.value();
    satVal = satSlide.value();
    brightVal = brightSlide.value();

    //Change background
    colorMode(HSB, 65535, 254, 255);
    background(65535 - hueVal, 254 - satVal, 255 - brightVal);

    //Display text
    textSize(width / 15);
    textAlign(CENTER, CENTER);
    text('Huehuehue', width / 2, 100);

    hueText = textSize(width / 60);
    hueText.text('Hue', canvas.width / 2 - 160, 500);

    satText = textSize(width / 60);
    satText.text('Sat', canvas.width / 2 - 35, 500);

    brightText = textSize(width / 60);
    brightText.text('Brightness', canvas.width / 2 + 100, 500);


function toggleLight() {

  let path = url + '/lights'
  httpDo(path, 'GET', toggleGetResponse);


function toggleGetResponse(getData) {

  let lights = JSON.parse(getData);
  lightState = lights["1"].state.on

  let body = {
    'on': !lightState
  let path = url + '/lights/' + lightNum + '/state/'
  httpDo(path, 'PUT', body, togglePutData);


function togglePutData(putData) {

  var response = JSON.stringify(putData);
  if (response.includes("success")) {
    lightState = !lightState

function changeLightColour() {
  var path = url + '/lights/' + lightNum + '/state';
  var body = {
    'bri': 255 - brightSlide.value(),
    'sat': 254 - satSlide.value(),
    'hue': 65535 - hueSlide.value()
  var path = url + '/lights/' + lightNum + '/state/'
  httpDo(path, 'PUT', body, changeColourResponse);

function changeColourResponse() {
  console.log('Colors changed!');

function changeBG() {
  let hr = hour();
  let mn = minute();
  let sc = second();


Week 1: Just another basic server.

For this week’s assignment, we were asked to create a simple http server using node.js and express. Both these terms were completely new to me and I decided to keep my ambitions in check and build something that works instead of the glorious failures of ICM and P.Comp in the semester past.

For starters, I familiarized myself with node and express with Dan Shiffman’s videos. (Link)

The ‘Programming A to Z’ website also has some great explanations on working with node.js and express (Link)

For my assignment, a combination of hanging out with small bots in ‘Hacking smart toys for AI learning‘ and listening to Leonard Nimoy narrating Ray Bradbury’s ‘There will come soft rains‘, I decided to make a web server to control a bot in the following ways:

  • Make the robot move ahead. (/forward)

  • Make the robot move behind. (/back)

  • Make the robot turn left or right. (/turn/[:left or :right])

  • Make the robot dance. (/happydance)

The code was pretty uneventful except the part of constantly having to turn the server on and off. Another part which tripped me over was that home I was encountering an error when I was trying “My network IP“ :8080 instead of localhost:8080. It works like a charm inside ITP though. Maybe, it was happening because I was on a hotspot but I had no idea to rectify it. I would like to know more about how to identify and rectify such network issues.

/* References used4-line server example from Tom Igoe's class: Shiffman's videos from coding train:*/

//Include express

let express = require('express');

//Create a server

let server = express();

//Serve static files from public

server.use('/', express.static('pages'));

//GET parameters

server.get('/turn/:direction', turnBabyTurn);

server.get('/forward', moveForward);

server.get('/back', moveBack);

server.get('/happydance', happyDance);

//Start the server


//Functions to send response to GET requests

//robot turn

function turnBabyTurn(request, response) {    

let newTurnState = request.params.direction;    

if (newTurnState == 'left') {        

response.send('The robot makes a sharp turn to the ' + newTurnState);} 

else if (newTurnState == 'right') {        

response.send('The robot makes a sharp turn to the ' + newTurnState);} 

else {       

 response.send('Something went terribly wrong. Bots are stupid like that. try left or right?');}    

response.end();}//Move back

function moveBack(request, response) {    

response.send('The bot retreats back not knowing what’s lies behind it.');    


//Move forward

function moveForward(request, response) {   

response.send('The bot whirrs forward towards an indeterminate future.');    



function happyDance(request, response) {    

response.send('The bot spins on its own axis silent and alone.');    


Currently listening: Keep Talking-Pink Floyd