Kid Sayanee

let's mashup
the web
and the real world

building a boat in a college semester

with PIC16 µ-controller at 433MHz, 8kb flash, 3kb ram

Creators need an immediate connection to what they create. That's my principle.

~ Bret Victor, Inventing on Principle

building a boat in a day-long workshop

with STM32 at 2.4GHz WiFi, 128kb flash, 20kb ram at

Inventor's delight =
our learning +
fast feedback

Computing layers Examples What changed?
App your ideas fast to prototype!
Framework browser api, javascript libraries now available
Programming v8 on ARM, Lua JIT, Arduino language support
Operating System Raspbian, Android embedded linux
Integrated Circuits hardware platforms more functionality
Physics physical sensors cheaper

web ≠ internet

Communication Layers Examples What's changing?
Web HTTP websockets, webrtc
Transport TCP, UDP
Internet Internet Protocol, MQTT IPv6, 6LowPan
Physical Ethernet, WiFi, 3G/4G, BLE wireless, low power

mashup with sensors

  • 1 in phones
  • 2 over http
  • 3 over ble

mashup with sensors

  • 1 in phones



Client Server Hardware
device orientation mobile
client web socket server web socket

code code


// in index.html's script tag
window.addEventListener('deviceorientation', function(event) {
  var tiltLR = event.gamma; // tilt device left to right
  var tiltFB = event.beta; // tilt device front to back
  var alpha = event.alpha; // degree twisted around the center

Web Sockets with

// in index.html's script tag
var socket = io();
if (tiltFB < 15.0) {
  socket.emit('no', username); // emit socket when it detects yes
} else if (tiltFB > 75.0) {
  socket.emit('yes', username); // emit socket when it detects no


characteristics tip
jittery use a smoothening algorithm
raw sanitize
change zero point
add a multiplier
high precision round down / up
uncalibrated calibrate it according to environment full-tilt repository parallax repository

keep in view

Device API Working Group

explore today

Sensorendipity with Android and JanOS with Firefox OS

Sensorenditpity in Android and JanOS in FirefoxOS to access sensor values in phones with

mashup with sensors

  • 2 over http

hardware platforms

Aruino Yun specs
μ controller: ATmega32u4
connect: WiFi Atheros AR9331
I/O pins: 20
analog pins: 12
firmware: Arduino

hardware platforms

Spark Core specs
μ controller: STM32
connect: WiFi TI CC3000
I/O pins: 18
digital pins: 8
analog pins: 8
PWM pins: 8
firmware: Arduino / C
Spark core hardware

wiring the rgb led

Wiring breadboard with an RGB LED and Spark core

// in JavaScript
httpPost('A7', 255); // Red: pin A7, value 255
httpPost('A5', 0); // Green: pin A5, value 0
httpPost('A6', 0); // Blue: pin A6, value 0

wiring the proximity sensor

Wiring proximity sensor with Spark Core
// in Firmware code with Spark API
int trigPin = D4;
int echoPin = D5;



Client Firmware Hardware
color thief,
one color
send a POST request to 3 pins spark's default tinker function: analogwrite RGB LED
sensor value = progress bar emit SSE every second Proximity sensor

code: browser -> ledcode

send http post request to rgb led

// in index.html's script tag
// call http post to 3 pins for RGB
var http = new XMLHttpRequest();
var url = '{DEVICE_ID}/analogwrite';
var params = 'access_token={ACCESS_TOKEN}&params={PIN},{VALUE}';'post', url, true); // and http.setRequestHeader
http.onreadystatechange = function() {
  if(http.readyState == 4 && http.status == 200) {
    // handle success and error

code: sensor -> browsercode

Firmware code

void loop() {
  if(millis() - old_time >= 1000){
    cm = rangefinder.getDistanceCM();
    Spark.publish("distance", distance); // every second publish distance
    old_time = millis();

JavaScript frontend code

var url = '{ID}/events/?access_token={TOKEN}';
var eventSource = new EventSource('https://' + url);
eventSource.addEventListener('distance', function(e) {
  // = distance
}, false);

explore today - control in JS

mashup with sensors

  • 3 over ble

wireless protocols

communication range power consumption
wifi 802.11x~ 100mmedium
ble 802.15.1~ 50mlow
zigbee 802.15.4< 10mlow
gsm> 1 kmhigh


BLE breakout specs
connectivity: BLE with NRF 8001


TI Sensor Tag specs
connect: BLE CC2541
sensors: IR temperature, humidity, pressure, accelerometer, gyroscope
battery: coin cell CR2032
Texas Instruments Sensor Tag for BLE and sensor dev board



Client Server Hardware
web audio node-sensortag TI sensor tag,
laptop with ble hardware
web sockets web sockets

code: sensortag <-> web audiocode

node sensortag

var SensorTag = require('sensortag'); {
	    function(callback) {
      function(callback) {
        setTimeout(callback, 2000);
      function(callback) {
        sensorTag.readIrTemperature(function(error, obTemp, ambTemp) {
          // emit socket to frontend with ambientTemperature

code: sensortag <-> web audiocode

Client code for Web Audio API

var context = new AudioContext();
var oscillator = context.createOscillator();

socket.on('gyroscopeChange', function (data) {
	oscillator.frequency.value = somethingCool(data.x); // process it

keep in view

explore today - JS + wireless protocols

get started today!

  • proximity
  • led
  • accelerometer
  • gyroscope
  • temperature
  • humidity
  • servo
  • ambience


  • css3 animation
  • web rtc
  • web audio
  • web sockets
  • server sent events
  • browser api
  • web gl

mashup web + real world

  • 1 sensors
  • 2 wearables
  • 3 robots
  • 4 satellites?

track our usage

learn from nature

discover the universe

Let's play with the
real   world !


slides at
slides code at