Java tutorials, experiments, and real-world projects by Frank Delporte,
Java Champion, Technical Writer at Azul, and lead maintainer of Pi4J.
Whether you're running Java on a Raspberry Pi, building desktop UIs with JavaFX,
exploring RISC-V single-board computers, or diving into JVM internals — you're
in the right place.
Topics: Java, JavaFX, Lottie4J, Pi4J, Java on Single-Board Computers, and much more...
📘 Book: Getting Started with Java on the Raspberry Pi
🎙️ Foojay and other Podcasts
📺 Videos
🗣️ Presentations
The mystery of the negative byte value in Java
A story of bits, bytes, signed and unsigned Some time ago there was a question on the Pi4J-forum caused by some confusion about a numeric value handled as a byte which was logged as a negative number -86 instead of the expected value 170. So this is my attempt to try to solve this mystery… ;-)
LED number display JavaFX library published on Maven
My very first open source JavaFX library is now available in the Maven repository! A small step for mankind, one giant leap for myself ;-)
DIY Arduino MIDI instrument
And another summer project got finished… ;-) My sons drum corps teacher triggered me to build an Arduino Midi controller so he could practice his rhythm skills.
Mission accomplished! The finished drum booth.
As a summer project requires, this project required a summer to get completed ;-) I still need to think about a big (double) door and how to make that one with or without glass. But the booth itself is ready and the drum moved for a first test and audio measurement.
Selecting sound isolation
To work out my box-in-a-box I needed two types of materials: something “fluffy” for the walls, and something “strong” to carry the floor.
Making a DIY drum booth
What do you get if you combine a drum-playing son and a father who doesn’t like to spend thousands of euros? A DIY drum booth! ;-)
Quick start Java development with Visual Studio Code
Great move of Microsoft! They provide an all-in-one installer for Java dependencies and Visual Studio Code. Take a look at https://devblogs.microsoft.com/visualstudio/announcing-visual-studio-code-java-installer/
Clean Raspberry Pi GPIO testing with the Breadboard Pi Bridge
Some time ago I ordered a “Breadboard Pi Bridge - Pi Ports to Breadboard in Numerical Order” and reworked my Pi test setup from the previous blogs. And it looks really good!
Pi4J to easily work with the hardware of a Raspberry Pi with Java
What is Pi4J See https://www.pi4j.com/1.2/index.html This project is intended to provide a friendly object-oriented I/O API and implementation libraries for Java Programmers to access the full I/O capabilities of the Raspberry Pi platform. This project abstracts the low-level native integration and interrupt monitoring to enable Java programmers to focus on implementing their application business logic.
Pi4J - Adding a REST interface with Spring Boot
As I was learning Spring Boot myself, I thought the easiest way to learn was trying to build an example and write about it. So here we go… :-)