Raspberry Pi with Java: Programming the IoT (Book Review)
Raspberry Pi with Java: Programming the IoT (Book Review)
A book review on several different ways to use a new Raspberry Pi, including a drone, a game console, and for brewing tea.
Join the DZone community and get the full member experience.Join For Free
Before beginning this book review, it was brought to my attention that I had to disclose lawyer speak in order to comply with FTC rules relating to bloggers.
Disclosure of Material Connection: I received this book free from Oracle Press / McGraw-Hill Education (Publisher) In exchange for a book review. I was not required to write a positive review. The opinions I have expressed are my own. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: “Guides Concerning the Use of Endorsements and Testimonials in Advertising.”
It is the year 2016, and by now we should be at more than a billion connected devices related to the Internet of Things (IoT) which numerous firms have predicted. If you’re like me a person who loves to tinker and discover things you have probably heard about the Raspberry Pi. On my journey to learn all things Pi I’ve come across many books related to the Raspberry Pi that utilized various programming languages, however when it came down to the Java language the books were pretty scarce.
Look no further, a new book has finally arrived that focuses on Java technologies to drive your Raspberry Pi projects. In this blog entry I will be reviewing the book Raspberry Pi with Java: Programming the Internet of Things (IoT) by Stephen Chin with James L. Weaver (Oracle Press). Technical editing by Mark Heckler.
The two book authors are some of the most respected in the IoT, Java, and JavaFX communities. Both Stephen Chin (Oracle) and James Weaver (Pivotal) are Java champions who are renowned speakers at many major developer conferences worldwide. The technical editor Mark Heckler (Pivotal) is also a well known Java geek who also speaks at many prominant conferences around the world.
For starters the authors begin with a very good introductory and summary of the chapters. After the summary of the chapters the book points out two links to download the source code for the book. Other programming books with source code usually point to their publishing company’s website. Fortunately, this book provides two places to obtain the source code. One at the publishing company (www.mhprofessional.com) and the other is hosted at the Github (https://github.com/RaspberryPiWithJava).
Chapter 1: Baking Pie
The authors gets you started by listing all the component parts and software necessary to develop on the Raspberry Pi. The instructions on how to setup and configure the Raspbian OS are thoroughly explained. I like how the authors discuss how to connect all the different Raspberry Pi models to your network. Keep in mind that the book was written prior to the announcement of the Raspberry Pi Zero model, so the book has no mention of it.
In chapter 1 they show you how to connect your Raspberry Pi using an Ethernet or Wireless connection. After you're successfully connected, the authors show you how to ssh into your Raspberry Pi remotely from the three major OS platforms (MacOS, Linux and Windows) through your terminal (command-line console). Once you're able to ssh into your Raspberry Pi you will be able to code/compile and run a Hello World Java console application.
Chapter 2: Your First Java Project
In Chapter 2, the authors begin by walking you through setting up the NetBeans IDE to remotely debug live running code on a Raspberry Pi. Once you get comfortable with the development workflow, the authors start out with a cool (hot) project on brewing the perfect cup of coffee! When beginning a project the authors always start off with a Bill of Materials detailing what and where to buy parts for a project.
In this chapter it delves into APIs (JSR 80) that allows your Java code to communicate with USB ports (usb4j). The authors show you how to read information from a USB port on an electronic scale device. The scale is used to measure the weight of things such as ground coffee beans. This chapter ends with the discussion of the topic of Commercial Licensing and FOSS. Learning about licensing options can help you navigate through legal matters if you decide to go commercial with your Java/Raspberry Pi product.
Chapter 3: Binary Timer
The authors goal in this chapter focuses on how to use GPIO (general purpose input output) pins. The GPIO pins are how the Raspberry Pi talks to analog and digital components such as LEDs, DC motors and light sensors. In this section you will learn the fundamentals of electronics such as power, Ohms law and what resistors you will need to purchase, etc. I love one of the tip blocks on "What is the Worst You Can Do to Your Raspberry Pi". This tip allows you to not feel intimidated when approaching a Raspberry Pi by explaining how rugged the Raspberry Pi computer actually is, and how to prevent mishaps or damaging the Pi.
The authors mention two Java libraries commonly used for accessing GPIO pins on the Raspberry Pi. One being the Device I/O library and the other Pi4J. In this section the benefits of using each library are fully detailed. This chapter is very hands-on by creating a basic project using LEDs on a breadboard that can count down in binary. Many Fritzing diagrams are presented for step-by-step instruction on how to wire-up components properly. In this chapter the authors mention helpful troubleshooting tips such as Java code to solve the button debouncing issues when dealing with physical buttons or switches in your circuits. Lastly, this chapter provides bonus content that teaches you how to measure and compare performance metrics when using the two Java libraries Device I/O library and Pi4J by turning LEDs on and off very rapidly. Here, both memory-mapped access (Low-level) vs Sysfs access (Higher-level) were compared. This will help you decide which strategy is best depending on your use-case.
Chapter 4: IoT Hat
Now with the fundamentals of the Raspberry Pi, Java and basic electronics out of the way, you can now tackle a magical project that will astonish friends and family. This project involves creating a magicians top hat with the ability to know what playing card was chosen without seeing the face of the card. The authors teach you about how to configure your Raspberry Pi to enable I2C, SPI, and UART protocols. This chapter focuses on learning about NFC/RFID devices such as smart card readers. Beware: This section involves soldering so get your flux on. Here, you will learn how to communicate with an RFID reader’s breakout board.
This project also teaches you about compactness and portability (cordless) because you will be hiding stuff in a top hat. To make things portable, the Pi will use a WiFi adapter and USB cell phone charging battery. The authors will also take you through native libraries required for Java to communicate with the NFC device so don’t be alarmed if you encounter Make files and permissions (typical in the Linux world).
Chapter 5: Line Runner
After learning skills for compactness and portability from chapter 4 the authors show you how to reuse your skills to build an autonomous robot! This should be the very reason to get this book. In the Bill of Materials all the parts (Makeblocks) you will need are detailed thoroughly. The robot will be able to anticipate obstacle while capable of following a lined path on a floor surface (Delivering mail comes to my mind). This chapter is focused on sensors, motors, and mechanical construction. With sensors the authors take you through how to use infrared and ultrasonic capabilities. When using motors this chapter explains pulse width modulation (PWM) to control the speed of the robot. The Java code examples are quite straight forward and concise.
Chapter 6: Tea Station
Not a coffee drinker, but still a Java fanboy? Well, this project is for all the tea lovers (including you) out there! This project is building a tea station to steep the perfect cup of tea. In this chapter the author discusses electronic scales (again) except ones having better precision due to tea leaves being extremely light in weight. The author goes on to discuss about temperature sensors that can determine how hot the tea should be when below the temperature of boiling water with very good accuracy. The author delves into serial (RS232 to TTL) communications with various vendors selling electronic scales (In chapter 2, USB was used). Learning this skill is invaluable because many older devices still use serial communications, so you can adapt your ideas with just about anything.
In this chapter the author really takes things to the next level compared to chapter 2 (brewing coffee), because he teaches you how to implement a snazzy JavaFX UI on a touchscreen device! Just like the chapter on brewing coffee the authors have an incredible depth of knowledge on teas and types of teas.
Chapter 7: Autonomous Drone
I’m sure you’ve heard a lot about the drone craze, well this chapter will knock your socks off! The authors will be employing a quadcopter and a Raspberry Pi capable of flying autonomously. Don’t be afraid, the drone in this project will not hurt you. Interestingly enough this chapter will use two WiFi adapters to be attached to the Raspberry Pi (Model B). One adapter is to talk to the drone itself and the other is used as a wireless access point (WAP) to remotely talk to the Raspberry Pi. In this chapter the author highlights an API called Autonomous4j by Mark Heckler. Mr. Heckler is also the technical reviewer of this book. I’ve actually seen the drone in action at a JavaOne conference where Mr. Heckler and Mr. Weaver conducted a live demonstration. The APIs discussed in this chapter are very easy to use, for example the following are some of the Java methods:
- takeoff() – Causes drone to start and take off.
- goLeft/goRight(int speed) – Given the percent of speed to fly left/right (its left or right).
- forward/backward(int speed) – Cause drone to go forward/backward given a percent of speed.
- goHome() – Drone flies back to where it lifted off from.
- land() – Land and stop.
Chapter 8: Retro Video Game Emulator
Whoa!? If you are an 80s or 90s kid who enjoyed arcades and game consoles (I know I did) then this chapter is about creating an Nintendo Entertainment System (NES) game console! Most of the parts from the bill of materials can be obtained from the popular electronics company Adafruit. The author teaches you how to build a game controller, attach a speaker, and attach a LCD touch display. This project will involve learning how to connecting GPIO pins to the Kippah board to control a touchscreen display. The author walks you through using a NES emulation Java library halfNES by Andrew Hoffman. As most of you know when dealing with emulators it isn’t legal to play game ROMs of popular games back in the day, unless you actually own the old game cartridge, so the author suggest heading over to a site having free games you can play. I’m sure if you own Mario Brothers you can get the game ROM and try it out. The author ends the chapter with more hacking tips such as overclocking your chip to increase the performance of your Pi. It’s a game so you need it to run fast!
Chapter 9: NightHacking RetroPi
After you’ve learned from chapter 8 on how to build a game console, this chapter will show you how to make a portable hand-held game device just like a Nintendo Game boy! The author is thoughtful in discussing about the pros and cons on various 3D printers and existing DIY communities at large. This chapter points out all the necessary software to print parts for your hand-held game device. The author provides great illustrations to step you through creating a polished product.
This book has opened my eyes to innovative ideas using Java with the Raspberry Pi. The content is well organized and easy to follow. Often other DIY books have difficulty explaining the integration between hardware and software, but this book blends the two together elegantly. This book is very definitive in terms of the numerous topics, vendors, components, comparisons and implementation strategies. The authors hit on practically every topic relating to how to command and control (many types of) devices.
A good number of projects are very hands-on with an emphasis on the engineering side of things as opposed to the software side (solely a software developer). If you like to build cool gadgets and comfortable with the Java programming language I urge you to get this book.
My only issue (tiny) is the paperback book’s illustrations are in black and white (gray-scale) which can make it difficult to see things such as colored resistors in the Fritzing diagrams or JavaFX UIs (User Interfaces). I believe the PDF version might be in color, but I’ve not seen it yet (just a hunch). But, overall I give this book a two thumbs up. By far, this book is the most comprehensive book combining two great technologies with a plethora of amazing DIY projects to date.
Published at DZone with permission of Carl Dea , DZone MVB. See the original article here.
Opinions expressed by DZone contributors are their own.