June 2015 Summaries

Utilizing a Raspberry Pi, this guide details the creation of a custom security camera capable of motion detection, facial recognition, and real-time alerts, catering to the necessity for timely information in security situations. The project requires a Raspberry Pi B+, a camera module, a PIR sensor for motion detection, and software like OpenCV for image analysis and PubNub for real-time communication. The system captures images when motion is detected, uses OpenCV to analyze these images for human faces, and stores them in a Parse database if a person is detected. Alerts are then sent in real time using PubNub, with the option to display these alerts on a web console. The guide also suggests potential enhancements, such as sending push notifications to mobile devices, and provides resources for further customization of the project.

This tutorial guides users through the process of creating a Raspberry Pi-controlled RGB LED light that can be remotely managed using an Android device, leveraging the capabilities of the PubNub platform for data streaming. It details the necessary hardware, such as a Raspberry Pi, RGB LED, resistors, and wires, and explains the differences between common cathode and anode LEDs. The guide provides step-by-step instructions for setting up the GPIO pins, configuring the breadboard, and coding in Python to use Pulse Width Modulation for controlling the LED. Additionally, it outlines how to build an Android interface using Android Studio, detailing the setup of UI components and integrating PubNub for real-time control of the LED's color through JSON messages. The tutorial emphasizes modular coding practices and suggests potential extensions, such as monitoring device presence on the PubNub channel, to further enhance the functionality of the project.

The text discusses the integration of Google Cloud Messaging (GCM) and PubNub for developing real-time mobile applications on Android, particularly focusing on facilitating push notifications. It highlights the benefits of using GCM, such as eliminating the need for developers to manage the complexities of creating a push notification system, as Google handles queuing and message delivery even when devices are offline. The integration with PubNub further simplifies the process by replacing third-party servers, allowing developers to leverage PubNub's real-time data streams alongside GCM's notification capabilities. The article provides a step-by-step guide on setting up a project using GCM and PubNub, detailing the registration process in Google's Developer Console and obtaining the necessary keys from PubNub's Admin Dashboard. It emphasizes the simplicity and efficiency of combining Google's native Android Notification API with PubNub's network, enabling seamless push notification delivery to Android devices.

The blog post explores how to transform a smartphone into a motion controller for real-time gaming using PubNub and Polymer, akin to devices like the Wii or Xbox Kinect. It provides a step-by-step guide on creating a customizable Material Design gamepad called PubMote, which can interface with HTML5 games through a web browser. The PubMote can feature various elements such as arrow keys, accelerometer bars, and action buttons, and is built using Polymer's Core and Paper elements following the Material Design standards. The process involves installing and importing necessary Polymer components and PubNub elements, setting up data binding and event handling, and incorporating accelerometer functionality to detect device tilts and shakes. The guide concludes by demonstrating how to integrate the PubMote with JavaScript-based browser games, exemplified through a modification of a Pac-Man game to use the PubMote for input.

The tutorial outlines a step-by-step guide for building a simple IoT proximity alarm using a Raspberry Pi and PubNub, highlighting the Raspberry Pi's suitability for IoT projects due to its open design and ease of use. It details the construction of a hardware setup involving a Raspberry Pi and an HC-SR04 ultrasonic rangefinder, utilizing a voltage divider to safely connect the sensor to the Pi's GPIO pins. Subsequently, it guides users through coding using Python, incorporating libraries such as GPIO and PubNub, to enable real-time, bidirectional communication with other devices via PubNub's data streams. The project culminates in creating a proximity alarm that not only measures distances but also sends alerts to a web interface and can be upgraded to communicate with a motion detector, demonstrating the potential for scalable, interactive IoT solutions.

This blog post explores the concept of remote configuration in the Internet of Things (IoT) by demonstrating a simple application to remotely control a device using a web browser. The example uses a Raspberry Pi Model B+, an LED, and a 490 Ohm resistor to create a basic IoT simulation that toggles the LED's state through a web interface. The project employs the RPi GPIO Python library and the PubNub Python and JavaScript SDKs to facilitate communication between the web application and the Raspberry Pi via the 'gpio-raspberry-control' channel. The demonstration showcases the fundamental design pattern that can be scaled to control multiple devices simultaneously and emphasizes the role of PubNub’s APIs as middleware in managing IoT communication. Additionally, the text highlights the potential for deploying similar applications to monitor, control, and analyze data from connected devices, indicating broader implications for IoT systems.

Backbone.js, a popular JavaScript framework, is used to create data-driven web applications that respond dynamically to real-time changes, as demonstrated by integrating it with PubNub’s JavaScript SDK. Inspired by the Programmer Competency Matrix, the post describes the creation of a miniature application that allows users to self-assess their programming skills, view aggregate scores, and receive real-time updates as others submit their scores. The application uses Backbone models, including Stat for aggregate score storage and Key for capturing user selections, and features a tabular UI where users can select their grades and submit scores, which are then synchronized across all browsers via PubNub. The dynamic update capability ensures that the Stat model is continually refreshed with the latest aggregate data, enhancing user experience in collaborative and multi-user interfaces, and the application can benefit from further improvements like centralized score data persistence to manage concurrent submissions effectively.