Programming the Internet of Things

Part III. Connecting to Other Things

Introduction

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In Part I, I stressed that the IoT is all about integration. You set up your development environment and built your first two applications. At the end of Part I, you had your applications up and running and generating some very basic performance data, but little more.

Part II advanced the integration concept further and helped you build out a basis for connecting with the physical world. You also established more advanced data collection, transformation, and storage capabilities for your two applications, enabling your CDA and GDA to finally do something a bit more useful, although they aren’t yet talking directly to each other.

Cue Part III. This is where you’ll take the next step forward in your integration journey and enable your applications to talk reliably with each other.

What You’ll Learn in This Section

There are purpose-built protocols for communicating between IoT devices and even many IoT-friendly cloud services, and they’re in active use as of this writing. These protocols tend to fall into one of two categories: publish/subscribe (pub/sub) or request/response. These categories simply refer to the style of messaging that devices agree on in order to send or receive data over the network.

Pub/sub protocols are generally best suited for those messaging situations in which one device wants to send data to one or more unknown recipients, based on a topic ...