Book Image

Raspberry Pi 3 Projects for Java Programmers

By : Rajdeep Chandra, John Sirach, Pradeeka Seneviratne
Book Image

Raspberry Pi 3 Projects for Java Programmers

By: Rajdeep Chandra, John Sirach, Pradeeka Seneviratne

Overview of this book

Raspberry Pi is a small, low cost and yet very powerful development platform. It is used to interact with attached electronics by the use of it's GPIO pins for multiple use cases, mainly Home Automation and Robotics. Our book is a project-based guide that will show you how to utilize the Raspberry Pi's GPIO with Java and how you can leverage this utilization with your knowledge of Java. You will start with installing and setting up the necessary hardware to create a seamless development platform. You will then straightaway start by building a project that will utilize light for presence detection. Next, you will program the application, capable of handling real time data using MQTT and utilize RPC to publish data to Further, you will build a wireless robot on top of the zuma chassis with the Raspberry Pi as the main controller. Lastly, you will end the book with advanced projects that will help you to create a multi-purpose IoT controller along with building a security camera that will perform image capture and recognize faces with the help of notifications. By the end of the book, you will be able to build your own real world usable projects not limited to Home Automation, IoT and/or Robotics utilizing logic, user and web interfaces.
Table of Contents (8 chapters)
Integrating a Real-Time IoT Dashboard

Adding the HD44780-compatible 16x2 character display

Let's start our project by connecting the 16x2 character display to the Raspberry Pi and show some text on it using Java. When looking around on the Internet for a 16x2 character display, this will often be a HD44780-compatible one. These displays are quite affordable and are used in a lot of projects. Before we attach this display to the Raspberry Pi, we need to check what kind of backlight is being used as there are both LED and EL types. In our schematic and connections, we will be connecting a LCD with an LED backlight.

The character display has a parallel interface, which means we will need a lot of pins to connect the display. We will be communicating in 4-bit mode with the display so we do not need to use all the pins that are available. The pin setup of this kind of display is mostly as follows, ordered by pin number:

  • Ground
  • 5V VCC, (not 3.3V)
  • Contrast...