Book Image

Android Things Quick Start Guide

By : Raul Portales
5 (1)
Book Image

Android Things Quick Start Guide

5 (1)
By: Raul Portales

Overview of this book

Android Things is the IoT platform made by Google, based on Android. It allows us to build smart devices in a simple and convenient way, leveraging on the Android ecosystem tools and libraries, while letting Google take care of security updates. This book takes you through the basics of IoT and smart devices. It will help you to interact with common IoT device components and learn the underlying protocols. For a simple setup, we will be using Rainbow HAT so that we don't need to do any wiring. In the first chapter, you will learn about the Android Things platform, the design concepts behind it, and how it relates to other IoT frameworks. We will look at the Developer Kits and learn how to install Android Things on them by creating a simple project. Later, we will explore the real power of Android Things, learning how to make a UI, designing and communicating with companion apps in different ways, showcasing a few libraries. We will demonstrate libraries and you will see how powerful the Android Things operating system is.
Table of Contents (10 chapters)

PWM as analog output

In the introduction we talked about the average value of a PWM signal. That average can be considered an analog value for the signal as long as the frequency is high enough that the circuits do not notice it. Many circuits will have voltage regulators to compensate for the variations on the input and in that case it will be in fact an analog output. This analog value is directly proportional to the duty cycle.

Since we only have one PWM available we will use a single color LED to visually understand how analog outputs work. In the case of the LED, the intensity of the brightness will be proportional to the value of the duty cycle.

We will use a red LED for this example, connected as shown in the following diagram. We connect the LED to the PWM pin, add a 330 Ω resistor to take care of the extra voltage, and then we connect again to ground. A mini breadboard...