February 2015 Summaries

C3.js is a graphing library that facilitates the creation of real-time, live-updating data visualizations with smooth transitions and a variety of chart types, making it easier to implement than traditional methods that often required complex workarounds. The introduction of the PubNub C3.js library enhances this capability by providing an easy way to update graphs in real-time through a function that wraps around C3, enabling seamless integration with PubNub channels for data streaming and publishing. Users can get started by including specific JavaScript files and initializing the eon-chart, which can be configured to display various types of charts such as spline, gauge, donut, and bar charts, and can auto-populate using the PubNub history feature. This integration encourages creativity in data presentation and supports all C3-supported graph types, allowing for unique and dynamic visualizations, with additional resources like demos and tutorials available for further exploration of real-time data streaming.

This tutorial expands on a previous guide by demonstrating how to create a collaborative, real-time camera app using the Tessel Camera and AngularJS, enabling users to view live photo feeds akin to a DIY IoT version of Instagram without manual updates. The process relies on the pubnub-tessel package for real-time messaging and uses a structured data format for seamless image posting. It involves setting up a simple HTML interface with AngularJS for data binding and Bootstrap for styling, while the JavaScript part incorporates the pubnub-angular service to manage real-time updates. The app utilizes Angular's ng-repeat to track and display data from multiple devices, ensuring the DOM updates with each new photo captured by the Tessel Camera, and leverages PubNub's capabilities to store and retrieve up to 500 messages.

The Tessel board is a versatile microcontroller that can be programmed with JavaScript and is equipped with various modules, including a camera module that allows users to capture and publish photos to a real-time picture feed. This blog post provides a guide on setting up and programming the Tessel camera with JavaScript to enable photo-taking capabilities. The setup involves cloning the necessary directory, connecting the Tessel board to WiFi, and installing the camera package using npm. Users are instructed to connect the camera module to the board, power it on, and verify the connection to WiFi. The process includes running specific code located in the /projects/streaming-camera directory to enable the camera's functionality, with options to modify the code for testing purposes. The instructions also cover using separate terminal commands to confirm server and client-side operations, with the potential to establish a real-time camera feed, as detailed in a subsequent series installment.

The text provides a comprehensive guide on building a mobile chat application using PhoneGap/Cordova, which allows developers to create apps for multiple mobile platforms using a single codebase written in JavaScript, specifically AngularJS. By leveraging HTML and AngularJS, developers can construct a web-structured app that adapts to various screen sizes without the need for learning native languages like Swift or Objective-C. The tutorial details the installation process for Cordova on iOS, including necessary tools like Xcode and ios-sim, and outlines the steps to create a PhoneGap/Cordova project. It explains the structure of a Cordova project, highlighting key directories such as "platforms" and "www," and emphasizes the use of AngularJS attributes for dynamic user and message listing. The guide also covers the integration of PubNub for real-time communication, enabling message subscription and user presence tracking, and provides instructions for testing the app on emulators and devices by building the Cordova code into a full Xcode project.

A team of high school students developed an iOS application called Paer in just 30 hours during the HackGenY hackathon, aiming to revolutionize the traditional business card. Utilizing Bluetooth Low Energy Technology (BluetoothLE), Paer allows users to exchange contact information and connect on social platforms by simply touching phones, offering a faster and cheaper alternative to NFC. The app eliminates the need for physical business cards by streamlining networking through real-time data sharing between devices, facilitated by PubNub Pub/Sub Messaging that enables communication in under a tenth of a second. The article also highlights additional resources and SDKs for mobile app and beacon development, showcasing the potential for rapid, interactive communication between devices using similar technologies.

In a continuation of their series on real-time data visualization, the blog post delves deeper into creating real-time charts by monitoring Node.js memory usage using Rickshaw, d3.js, and a specific npm module. This module seamlessly integrates with the Rickshaw-PubNub library, facilitating the logging of memory usage and the spawning of an express static server. The real-time memory usage is captured through `process.memoryUsage()` and published at regular intervals to a specified PubNub network channel. The post provides a step-by-step guide to setting up the module, which includes installing it via npm and configuring it to run on a local express server, ultimately allowing users to visualize and modify a real-time Node.js memory profile chart.

Beacon technology, leveraging Bluetooth Low Energy (BLE), is rapidly evolving, with increased interest from startups due to its potential for low-energy, one-way communication. While Apple has integrated beacon tech since the iPhone 4s, Android's support began with its Lollipop update, allowing devices like the Nexus 6 and 9 to act as beacons. Beacons emit small amounts of information over a 230-feet radius without establishing a connection, similar to a lighthouse, using minimal power—often a coin battery lasting over two years. Key protocols such as iBeacon, Estimote, and AltBeacon standardize how data is structured and transmitted, with signal strength helping estimate proximity despite environmental influences. A novel approach combines PubNub's data streaming capability with beacons, enabling bidirectional communication that maintains low energy use, exemplified by a retail scenario where a store beacon interacts with a customer's phone via PubNub channels to deliver personalized notifications. This integration showcases an enhanced beacon capability across platforms, with ongoing tutorials supporting developers in implementing these technologies.