Firefox OS Tricorder

The following slides are available in this presentation:

Firefox OS Tricorder

Reading Device Sensor Data in JavaScript

Robert Kaiser, "KaiRo" <kairo@kairo.at>
Program Manager, Mozilla QA

Slides: http://slides.kairo.at/fosdem2015/

Created for Mozilla Developer Room at FOSDEM 2015 in Brussels.
Written in HTML 5 with CSS 3 and JavaScript.
Navigation via links on all slides, via access keys (e.g. "n"/Alt+Shift+N for "next") or back/forward arrow keys
Contents
01/2015 Robert Kaiser - "Mozilla", "Firefox" and their logos are trademarks of the Mozilla Foundation; Star Trek and related items are trademarks of Paramount Pictures.

What is a Tricorder?

Sensor device as seen on "Star Trek"

Displays whatever data is needed at plot speeds and resolutions.

Module

HTML (switch, display)
JS Object
- 2 Methods: activate(), deactivate()

Position Module

GPS, WiFi/Cell Location

API: Geolocation

Permission: geolocation

Position: Code

  this.watchID = navigator.geolocation.watchPosition(
    function(position) { ... },
    function(error) { ... },
    {enableHighAccuracy: true, maximumAge: 10000, timeout: 60000}
  );

  navigator.geolocation.clearWatch(this.watchID);

Gravity Module

Accelerometer, Magnetic Compass

APIs: deviceorientation, devicemotion events

Permissions: ---

Gravity: Code

  window.addEventListener("deviceorientation", this.orientEvent, true);
  window.addEventListener("devicemotion", this.motionEvent, true);

  orientEvent: function(orientData) {
    orientData.alpha / .beta / .gamma (in °)
  },
  motionEvent: function(event) {
    event.accelerationIncludingGravity.x / .y / .z (in m/s²)
  },

  window.removeEventListener("deviceorientation", this.orientEvent, true);
  window.removeEventListener("devicemotion", this.motionEvent, true);

Sound Module

Microphone

APIs: WebRTC(getUserMedia), WebAudio

Permissions: audio-capture

Environment Module

Light, Proximity; Flashlight

APIs: devicelight, deviceproximity events; Camera API

Permissions: ---; camera (for Flash)

Device Module

Battery

APIs: Battery

Permissions: ---

Table of Contents