Raspberry Pi on foojay.io - Friends of OpenJDK

Using the Raspberry Pi Sense HAT with Pi4J Drivers

Wed, 01 Jul 2026 08:38:00 +0000

One of the biggest advantages of the Pi4J Drivers project is the ability to interact with complex hardware through simple and intuitive Java APIs. A great example of this is the Raspberry Pi Sense HAT, one of the most popular Raspberry Pi add-on boards and the hardware platform used in the Astro Pi program aboard the International Space Station.

Instead of manually implementing communication with multiple sensors and devices, Pi4J Drivers provides a ready-to-use driver that makes accessing the Sense HAT straightforward and enjoyable.

Pi4J Drivers: Simplifying Sensor and Hardware Integration in Java

Thu, 25 Jun 2026 07:07:08 +0000

When developing Java applications for Raspberry Pi, Pi4J is one of the most popular libraries for accessing GPIO, I2C, SPI, PWM, and other hardware interfaces. However, interacting directly with these protocols often requires a significant amount of code and a deep understanding of the underlying hardware.

This is where the Pi4J Drivers library become extremely valuable.

What is Pi4J Drivers?

Pi4J Drivers is a companion project to Pi4J that provides ready-to-use drivers for a wide range of electronic components, including sensors, displays, I/O expanders, and actuators. Instead of implementing low-level communication from scratch, developers can leverage tested and reusable APIs to interact with hardware devices.

Bringing Raspberry Pi Development to Quarkus with the Quarkus Pi4J Extension

Tue, 23 Jun 2026 07:30:00 +0000

Java developers building applications for Raspberry Pi often face a common challenge: combining hardware access with modern application frameworks.

Pi4J has become the standard way to access GPIO, I2C, SPI, UART, and other Raspberry Pi interfaces from Java applications. On the other hand, Quarkus has established itself as one of the most innovative Java frameworks, offering fast startup times, low memory consumption, and a developer-friendly experience.

The Quarkus Pi4J Extension brings these two worlds together, making it easier than ever to build hardware-enabled applications using the Quarkus ecosystem.

I Benchmarked Java on Single-Board Computers: Orange Pi 5 Ultra and Raspberry Pi 5 Lead the Pack

Wed, 04 Mar 2026 06:52:00 +0000

In my “Java on Single Board Computers” series, I already published several posts and videos in which I unpack the board, connect it for the first time, and try to install and run some simple Java code. In this post, I want to share some benchmarks of Java on these boards to get a better idea of the performance we can expect from Java on these platforms.

Already published in this series:

From “Crypto AI” to general AI: Do AI agents dream of electric langoustines?

Mon, 23 Feb 2026 18:11:54 +0000

A Blade Runner riff for a world where the lobster ships paid endpoints while humans still argue about the roadmap.

The shift that matters for agent commerce - From “Crypto AI” to general AI

Today, you can search the web all day and never see an invoice.

That happens because you are not the paying client.

The commerce runs through ads, affiliate deals, and platform incentives, so results often optimize for who pays, not for what you asked for.

First Test of Java on the Orange Pi (ARM and RISC-V)

Wed, 28 Jan 2026 06:52:00 +0000

As part of my 2026 learning goals around Java on Single Board Computers and RISC-V (see this post about x86 versus ARM versus RISC-V ), I’ve been asking various suppliers to send me evaluation boards. After testing the LattePanda IOTA , I received two boards from OrangePi to evaluate: the OrangePi 5 Ultra (ARM) and the OrangePi RV2 (RISC-V).

I got both boards for free, but what I write here and show in the video is not controlled by OrangePi or any other supplier.

Java on Single Board Computers: x86 vs ARM vs RISC-V

Fri, 23 Jan 2026 06:17:00 +0000

Ever since I started my #JavaOnRaspberryPi journey in 2019, which resulted in my book “Getting Started with Java on the Raspberry Pi ”, I’ve been fascinated with these tiny, inexpensive computers. For 2026, I’ve set one of my goals to experiment with Java on various Single-Board Computers (SBC), going beyond my “Raspberry Pi comfort zone.” The market is flooded with SBCs ranging from budget boards (tens of euros) to powerhouses (hundreds of euros). One of the reasons of this price range is the difference between the processors they use. Raspberry Pi uses an ARM processor, but RISC-V is gaining momentum, while Intel maintains its presence. So before I start experimenting, now is the perfect time to compare these three processor families and understand their differences.

Foojay Podcast #85: Code, Community, and Opportunity: Making Tech Accessible for Everyone

Mon, 08 Dec 2025 06:07:00 +0000

What if the future of Java depends on who we invite to learn it today?

In this Foojay Podcast, we’re diving into something that affects all of us in the Java community: How can we inspire the next generation of developers, and how do we make the developer world more inclusive?

In this episode, you’ll hear four incredible guests who are actively working to make tech more accessible and inclusive. First, Daniel De Luca talks about Devoxx for Kids and how they support underprivileged students in IT education. Then Kenny Schwegler shares his insights on how we can actively promote diversity and inclusion in tech. Cassandra Chin, the youngest Java Champion and author, talks about inspiring young coders through hands-on projects and making technology fun. And finally, Igor De Souza discusses his mission to bring Java into Raspberry Pi education and bring more Java into coding clubs worldwide.

foojay – a place for friends of OpenJDKJava 21+ on Raspberry Pi Zero 2 is Back In Business

Thu, 04 Dec 2025 08:46:00 +0000

As described before on Java 21+ Not Working on Raspberry Pi Zero 2 , a problem appeared to execute Java code on the Raspberry Pi Zero 2 with OpenJDK 21 or higher. Reason: in OpenJDK 21 the Just-In-Time (JIT) compiler has been improved, but this change doesn’t work correctly on the ARM Cortex-A53 processor as used in the Zero 2. It’s another type of processor compared to, for instance, the Raspberry Pi 4 (Cortex-A72) and 5 (Cortex-A76).

Java 21+ Not Working on the Raspberry Pi Zero 2

Wed, 02 Jul 2025 07:46:09 +0000

This story is about how “Write Once, Run Anywhere” got broken in a specific use case. It reveals the complexity of maintaining this “Run Anywhere” principle. At the same time, it shows how the OpenJDK community already detected this issue and has a fix available for the next update.

Problem on Raspberry Pi Zero 2

Dieter Holz was experimenting with Pi4J V3 on a Raspberry Pi Zero 2. Because this version requires Java 21 or newer, he upgraded his OS to a newer Java version and found out that no Java code could be executed. He tried with Java 21 and 24, and neither worked correctly, although Java 17 runs without problems.

Demo Application with CRaC and Loading Data in Memory

Thu, 13 Mar 2025 08:11:19 +0000

Coordinated Restore at Checkpoint (CRaC) is a JDK project initiated by Azul. With CRaC, you can start Java programs with a shorter time to the first transaction and less time and resources to achieve full code speed. This is achieved by taking a snapshot (checkpoint) of a fully warmed-up Java process and launching one or more new JVMs from that snapshot.

I have been experimenting with CRaC on a Raspberry Pi in 2023 and blogged about it, first when it didn’t work yet , and a second time when it did work perfectly .

Pi4J Welcomes Java 21 on the Raspberry Pi

Thu, 20 Feb 2025 10:49:07 +0000

Pi4J provides 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.

The project “hides” the complexity to interact with electronic components through different ways of communication (SPI, I2C, PWM,…) by providing Java interfaces on top of native libraries that can interact with the GPIO (General Purpose Input/Output) pins on the Raspberry Pi.

Recently, the development of the Pi4J library faced a decision point: “Should we stick to Java 11 for existing projects and old Raspberry Pi’s (with ARMv6 ), versus moving on and making use of better and more performant Java code with the latest Long Term Support (LTS) version?”

Crafting Your Own Railway Display with Java!

Mon, 18 Nov 2024 08:46:31 +0000

Have you fancied to have your own railway display at home? If you love traveling by public transport and always jump on the train just before the door closes like us, it’s really cool and highly efficient to have your own personalized display.

Background

Without live data, this project could not work. Luckily, all the data we needed was publicly and freely available with Nederlandse Spoorwegen (NS) APIs. To access them, you only need to create an account in the NS API Portal and subscribe to the APIs you want to use.

A Fresh Look at Embedded Java

Wed, 11 Sep 2024 07:37:10 +0000

Since its inception, Java has promised to “Write Once, Run Anywhere.” In its early days, the main focus of Java was embedded devices, such as set-top boxes and televisions.

But soon, it became one of the leading programming languages powering high-scale business applications that can handle massive amounts of transactions with high throughput.

Because those use cases are very visible and there are a lot of job opportunities within that area, we tend to forget that Java on embedded is also still very much alive and kicking!

Foojay Podcast #55: Embedded Java, Part 2

Mon, 01 Jul 2024 08:21:42 +0000

As a backend developer, you may not realize that Java was initially born on embedded devices like set-top boxes and gateways. We discussed this topic for the first time almost three years ago in Foojay Podcast #2 with James Gosling, Johan Vos, Erik Costlow, and Frank Delporte .

In this episode #55, we look into the history of the Java Micro Edition and how things evolved. Nowadays, with processors becoming increasingly powerful, we can run the exact same Java runtime on any Linux system, from the biggest cloud servers to the smallest Raspberry Pi Zero.

Evolutions in the Pi4J library by Tom Aarts and Robert von Burg

Fri, 24 May 2024 12:16:02 +0000

Multiple improvements have been implemented in the new release, V2.6.0 (2024-04-29) of Pi4J, 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 blog post will give you a quick overview and an interview with Tom Aarts and Robert von Burg, two of the main contributors.

Ongoing I2C Improvements
PWM Hardware Support on Raspberry Pi 5
New Class to Get Board Info
Interview with Robert von Burg
Interview with Tom Aarts
Conclusion

Ongoing I2C Improvements

Robert von Burg worked on improvements to the I2C implementation in Pi4J. The changes are in pull request #351 and allow atomically executing multiple I2C calls in a thread safely, plus other improvements. See this blog post for more details .

Building a Simple Home Assistant using Langchain4j and Raspberry Pi

Sun, 12 May 2024 05:31:16 +0000

Many believe that the future of IoT is AI. Building a Smart Home Assistant is less complex today than ever before. AI has become so accessible that you only need an internet connection and a computer to connect to an API.

While training specialized deep learning models or using commercial APIs to harness machine learning for specific deterministic use cases is still an option, it is now more common and accessible to use LLMs. Today, you can effortlessly utilize numerous LLMs from various providers through an LLM orchestration framework like Langchain4j . This framework not only allows the use of LLMs but also provides components that simplify the creation of AI applications such as chatbots and question-answering systems. With these tools, anyone can assemble a Generative AI-powered app in minutes.

Using my new Raspberry Pi to run an existing GitHub Action

Tue, 23 Apr 2024 18:45:04 +0000

Recently, I mentioned how I refactored the script that kept my GitHub profile up-to-date. Since Geecon Prague, I’m also a happy owner of a Raspberry Pi:

[

](https://twitter.com/nicolas_frankel/status/1715313240568197233 )

Though the current setup works flawlessly - and is free, I wanted to experiment with self-hosted runners. Here are my findings.

Context

GitHub offers a large free usage of GitHub Actions:

GitHub Actions usage is free for standard GitHub-hosted runners in public repositories, and for self-hosted runners. For private repositories, each GitHub account receives a certain amount of free minutes and storage for use with GitHub-hosted runners, depending on the account’s plan. Any usage beyond the included amounts is controlled by spending limits.

Java on Raspberry Pi 5 with Pi4J

Sat, 06 Apr 2024 11:08:20 +0000

In October 2023, Raspberry Pi announced version 5 of its affordable single-board computer with 4GB (60$) or 8GB (80$) of memory.

Soon after the first boards were delivered, it turned out the Pi4J library wasn’t compatible with this new board. Pi4J is a library to create Java applications for the Raspberry Pi that can interact with electronic components through the GPIO pins.

But because the Raspberry Pi 5 uses a new approach, with the new RP1 chip , to connect the SoC with these pins. Thanks to the RP1, it was possible to seperate GPIO, SPI, I2C, USB, ethernet,… from the SoC to make it easier to develop newer boards. However, this new approach wasn’t supported by the PiGpio library used in Pi4J V2.

Controlling LED Strips with Java and JBang

Mon, 22 Jan 2024 18:08:51 +0000

One of the most “fancy” electronic components is definitely… a LED strip. It’s really cool to control a long strip of lights with only a few lines of code.

But, there is a problem. The timing of the signals is crucial to reliably control these strips. Both Python and Java on a Raspberry Pi can struggle with these timings as they are running on Linux, a non-real-time operating system.

So, for instance, pauses in the garbage collection of the Java virtual machine, or any glitch in the operating system can cause unexpected effects on the LED strips. That’s why in most projects, a microcontroller (Arduino, Raspberry Pi Pico, ESP32,…) is used to drive the LED strip.

Pi4J Operating System for Java development on Raspberry Pi

Fri, 11 Aug 2023 10:19:50 +0000

Yes, the Raspberry Pi Operating System is awesome! But the Pi4J project made it even more awesome by adding “goodies” for Java developers! Pi4J OS is not yet another OS, but the official Raspberry Pi OS, with additional tools and preconfigurations to make it the ideal OS for any Java and JavaFX developer who wants to use a Raspberry Pi.

The project is shared on GitHub and documented on the Pi4J website . The zip-compressed archives of released versions can be downloaded from pi4j-download.com .

Temperature, humidity, and pressure in BME280 Sensors with Java

Thu, 03 Aug 2023 07:16:36 +0000

To make it as easy as possible to get started with Java on the Raspberry Pi to interact with electronic components, I started a new section on the Pi4J website with JBang examples .

In this tutorial, I want to show you how you can read the temperature, humidity, and pressure from a BME280 Sensor.

What Is Used?

As explained on the websites of each project:

Pi4J

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.

Running a CRaC Java application on Raspberry Pi

Wed, 05 Jul 2023 12:23:19 +0000

With the April release of the Zulu Build of OpenJDK, Azul announced the integration of CRaC in its version 17 of Java for Linux . Coordinated Restore at Checkpoint (CRaC) is a feature introduced in OpenJDK to improve Java’s application startup and warmup times to milliseconds from seconds or even minutes, by allowing a running application to pause, snapshot its state, and restart later, even on a different machine.

CRaC is the final step after previous projects by Azul in multiple client projects in the automotive and IoT industry. Infotainment systems for car, gateways in electronic systems, and other use-cases require high-speed startup of their applications running on embedded ARM32 and ARM64 systems.

Foojay Podcast #22: When Profession and Fun Overlap

Mon, 15 May 2023 07:47:29 +0000

Let’s talk about programming for fun. Grab your Lego and robots, and let’s talk about STEM and STEAM!

As a developer, we all get frustrated occasionally when a bug messes up our schedule, and we have to dive deep into the code to find a solution.

But still, many of us keep coding in our free time as we love to do it and want to create amazing stuff.

In this episode of the Foojay Podcast, we talk to volunteers from different organizations where coding is used to inspire children to become engineers or at least learn to make good use of computers and the tools around them.

FEPCOS-J (1) – Description, Impression of Usage, Current State

Wed, 26 Apr 2023 06:09:41 +0000

Abstract: FEPCOS-J has arisen in the context of my work in the field of robot sensor networks. It implements a Java-language extension that frees a Java developer from network programming and supports cross-system concurrency. This article gives you an impression of using FEPCOS-J based on a simple example.

So far, FEPCOS-J is a prototype with 1629 lines of Java-code. I develop and test it on my own within a toy robot-based amd64 / x64 Linux OpenJDK 17 environment, which communicates via a private and secured IPv4-network.

Coroutines on the RaspberryPi (Pi4J-Kotlin)

Sat, 01 Apr 2023 09:05:29 +0000

If you didn’t know already, Pi4J has had a Kotlin DSL for quite some time now.

And I’m here to announce the latest release v2.4.0 with a sack of additions and to tell you about all the good stuff that’s been added since the first release .

Coroutines {#h2-0-1-coroutines}

If the pi4j { ... } wasn’t good enough for ya, and you want to use coroutines instead of weaving fat threads on your precious precious Pi, you can now use the new pi4jAsync { ... } block—It can do everything pi4j { ... } does + you can run suspended functions within.

Control your Arduino with Spring

Sat, 25 Mar 2023 07:21:04 +0000

Have you ever wanted to control your Arduino board from a Raspberry Pi, or your computer, using only Java and not the Arduino language?

In this article, I show how I created a web app to control my Arduino with a Raspberry PI using Spring. And so this is another article about Java on Raspberry PI or perhaps this time I can say Java and Arduino.

Idea

A simple Spring app where I can create a REST interface to control one of the Arduino GPIOs. I can plug a LED and build a simple blink LED example.

Controlling a LED Strip with Pi4J and JBang

Mon, 28 Nov 2022 13:07:06 +0000

In an earlier post here on Foojay.io, JBang and Pi4J were used to control a LED and button connected to a Raspberry Pi .

This week Robert von Burg, one of the main contributors of the Pi4J project, shared on Mastodon another project where a LED strip is controlled via I2C.

This is the result, notice the Foojay.io startup artwork 😉

Wiring

The Raspberry Pi in the video is attached to a custom PCB used by Robert in medical cabinets .

Kotlin on the RaspberryPi (Pi4J-Kotlin)

Thu, 17 Nov 2022 13:37:18 +0000

Pi4J is considered the project that brought the JVM to the RaspberryPi.

It has been up for more than a decade allowing developers to write sophisticated, high-level, yet simple software on the RaspberryPi.

And we’re glad to make it even more simpler and powerful!

For quite some years now Kotlin has been a most welcome language in the JVM ecosystem and the modern development toolchain.

Many factors led to this great reality, most notable to me is Kotlin’s non-disruptive integration and seamless developer experience.

Pi4J V2.2.0 Released

Wed, 31 Aug 2022 17:09:19 +0000

One year after the first release of V.2 of Pi4J , a new release was published. Pi4J providesfriendly object-oriented I/O API and implementation libraries for Java Programmers to access the full I/O capabilities of the Raspberry Pi platform.

And what an amazing achievement with this new release! No major issues were found in the previous release, but several small fixes were added by more people than ever before in the Pi4J-history. This is a real confirmation of the openness of this project and how a community can work together to further improve a project.

Blink a LED on Raspberry Pi with Vaadin

Fri, 25 Mar 2022 14:44:02 +0000

As I’m becoming a senior developer, at least in terms of age, I’ve transitioned from one language to another.

One of my main interests has always been clean, easy-to-understand UIs (User Interfaces). That journey started for me with Director (to create multimedia CD-ROMs), Flash website animation, and Flex Rich Internet Applications (= “Flash on steroids”).

When I started developing with Java over 10 years ago, we had some projects with the early versions of Vaadin and JavaFX.

Controlling Electronics with JBang on the Raspberry Pi

Mon, 21 Feb 2022 10:08:06 +0000

Want to get started with Java programming on the Raspberry Pi?

JBang is a great way to create your first program to control electronic components connected to the GPIO pins.

What is JBang?

As described on their website :

JBang lets Students, Educators and Professional Developers create, edit and run self-contained source-only Java programs with unprecedented ease.

Want to learn, explore or use Java instantly without setup?
Do you like Java but use python, groovy, kotlin or similar languages for scripts, experimentation and exploration?
Ever wanted to just be able to run Java from anywhere without any or very minimal setup?
Ever tried out Java 11+ support for running .java files directly in your shell but felt it was a bit too cumbersome?

JBang lets you do all this!

Installing Java with SDKMAN on Raspberry Pi

Mon, 07 Feb 2022 12:23:15 +0000

If you create a new SD card for a Raspberry Pi with the operating system, you can choose the “Raspberry Pi OS Full (32-bit)” edition, which includes Java 11. But a lot of the other available OS-versions don’t have Java included.

There are many ways to install Java but, personally, I find SDKMAN the easiest one to use.

It allows you to easily install a JDK, but also to switch between different versions.

Template to Get Started with Pi4J and JavaFX on Raspberry Pi

Thu, 13 Jan 2022 12:07:26 +0000

The Pi4J project wants to be the starting point for everyone who wants to use Java on the Raspberry Pi, being it a headless, JavaFX-user interface and/or GPIO-controller project.

Pi4J 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.

Sending sensor data from Raspberry Pi Pico to HiveMQ Cloud

Wed, 05 Jan 2022 11:42:42 +0000

In the previous two posts in this series, we used Java on the Raspberry Pi mini-computer to send sensor data to HiveMQ Cloud, and visualize it on a dashboard.

Now we are going to add some more data to our messaging system with another member of the Raspberry Pi family: the Pico, and add this new data to the JavaFX dashboard from part 2.

Java Modules in the Pi4J Project?

Thu, 23 Dec 2021 15:28:39 +0000

Java modules have been a big discussion point before in many places.

And this is now also causing some headaches in the Pi4J project…

About Pi4J V2

The Pi4J project (started in 2012) aims to unite Java programming with electronics. By using the Pi4J dependency in a project, electronic components connected to the GPIO-pins (General Purpose Input/Output) of the Raspberry Pi can be controlled as objects in the Java code. Pi4J uses native libraries to control the GPIOs so you - as a programmer - donʼt need to be fully aware of all the “magic” that relates to hardware communication.

MQTT on Raspberry Pi (Part 2)

Wed, 22 Dec 2021 14:58:21 +0000

In the previous post we started our discovery of HiveMQ Cloud with Java on the Raspberry Pi. We created an application to send measurements of various sensors to the HiveMQ Cloud MQTT broker. Using an online websocket client we verified the transition of the messages, and could see the data being published to this online message queue.

Now we will take the next step and subscribe to these topics to receive the data in a dashboard, created with JavaFX.

MQTT on Raspberry Pi: Sensor Data to HiveMQ Cloud with Java and Pi4J

Wed, 15 Dec 2021 09:54:37 +0000

A few years ago I did my first experiments with an MQTT server (Mosquitto) running on a Raspberry Pi to connect an Arduino and Raspberry Pi for the drumbooth of my son . The full process is described in my book “Getting Started with Java on the Raspberry Pi” .

In this series of articles we are going to take a different approach with an online MQTT-compatible service: HiveMQ Cloud . The biggest advantage: no need for an always-on server we must manage ourselves. Yes, Mosquitto runs on a inexpensive Raspberry Pi, but still we require to keep it up-and-running if we use it as the “central hub” to distribute data.

Getting Started with Java 17 on the Raspberry Pi

Sat, 25 Sep 2021 13:56:53 +0000

As part of the Foojay Virtual OpenJDK 17+ JUG Tour , I was asked to present the state of Java and JavaFX 17 on the Raspberry Pi.

So, a perfect opportunity to freshen up my #JavaOnRaspberryPi presentation with some hot-off-the-press versions.

UPDATE 2021-08-30: the recording of the presentation has been published on YouTube.

In the past, I have been experimenting with Java 16 on the Raspberry Pi (see “Building OpenJDK from GitHub Sources on 64-bit Raspberry Pi ”) but now that version 17 is waiting around the corner, it’s time to prepare our Raspberry Pi for the upcoming new “long-term-supported” (LTS) version.

Announcement: Pi4J V.2 Released!

Mon, 30 Aug 2021 12:13:54 +0000

After long rework, the Pi4J library (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) has taken a big step with the first release of the V.2.

The Pi4J Project was started in 2012 by Robert Savage , the same year the Raspberry Pi was introduced as a tool to provide Java developers a simple and familiar object-oriented interface library to access the low-level I/O capabilities of the Raspberry Pi including GPIO , I2C , SPI , PWM , and Serial communications. Pi4j program structure

Java in Education: Combining Java with Raspberry Pi and the Pi4J Library

Tue, 29 Jun 2021 07:40:55 +0000

The interviews in this post are part of an article published (in German) in Java Magazine . You can get a 25% discount for a new kiosk subscription with the following code: delporte_kiosk25

Although a lot of universities and high schools focus on Python and C# in their program, there are luckily a lot of others who go “full Java”. Don’t get me wrong, I definitely don’t want to start a “programming-languages-war”, but Java is the language I used myself more than any other for the last 10 years. Setting up a new project or building a proof-of-concept for a new idea, is a matter of hours. And there is always a solution for the problem I need to solve. This is probably true for each developer who has enough experience in the language used the most. But having used and experimented with many other languages, I still keep returning to my “one true love”, being Java, as it always delivers the result I’m aiming for, with the right amount of code to be readable, understandable, and testable!

Gluon Update, Dual Screen Raspberry Pi , IntelliJ JavaFX Project Wizard

Fri, 04 Jun 2021 07:27:41 +0000

Last week, Johan Vos of Gluon, released a video with a status update of JavaFX. In this post we are going to take a deeper look into one of the announcements: dual screen support on Raspberry Pi.

Announcements by Gluon

Since Java switched to a 6-month release cycle, JavaFX has done the same, so next version will be number 17. Keep in mind, although Java and JavaFX are on the same version-number, you can still use Java 11 and combine it with the JavaFX 17 runtime if you want to benefit from its improvements. Up till now, there were no breaking changes in either of the frameworks which force you to use a Java-version higher than 11.

Interviews with Robert Savage & Johan Vos on Java on the Raspberry Pi

Fri, 28 May 2021 07:14:26 +0000

This post is part of an article published (in German) in Java Magazine . You can get a 25% discount for a new kiosk subscription with the following code: delporte_kiosk25

Here on Foojay.io, you can find already a long list of articles about Java on the Raspberry Pi . As you may know, already I’m a big fan of this combination. The Raspberry Pi on one side is a very cheap computer that allows you to experiment with electronic components thanks to the Pi4J library. And on the other hand, JavaFX is the ideal framework to build user interfaces that can directly control these components, all in one application!

Controlling an LCD Display with Spring and Thymeleaf on the Raspberry Pi

Wed, 19 May 2021 07:10:12 +0000

Igor De Souza shares on his blog a lot fun and inspirational experiments with Java on Raspberry Pi. Some of those were already shared here on Foojay.io:

This time we want to highlight his work which combines a web app made with Spring and Thymeleaf, to control an LCD display connected to a Raspberry PI.

JavaFX Running in Kiosk Mode on the Raspberry Pi

Tue, 27 Apr 2021 14:39:50 +0000

Combined with an inexpensive touch screen, the Raspberry Pi makes for a perfect controller for a machine or game console. Let’s see how we can use Java and JavaFX to build a test application that also communicates with the pins of the Raspberry Pi to control a LED.

We have done something before already in the post “Light Up your Christmas Tree with Java and Raspberry Pi” , so what’s new here?

Java Development with VS Code on the Raspberry Pi

Tue, 16 Feb 2021 11:09:39 +0000

In the post “Welcome to VS Code for Java” you can find a full description and a list of tips and plugins for Java development with Visual Studio Code.

But… did you know you can also use it on the ARM-processor-powered Raspberry Pi? Until recently this was not available in an official version for the Raspberry Pi, but luckily Microsoft decided to release new versions with installers for both 32-bit and 64-bit Raspberry Pis .

Vert.x Example on the Raspberry Pi with a Virtual Potentiometer

Wed, 20 Jan 2021 08:35:52 +0000

The Raspberry Pi allows us to do a lot of electronic projects without having to wait for ordered components… or to even buy them at all… by using virtual components: “Invest your time before you invest your money and build something before you buy the component.” For example, If you don’t have a 7 segment display you can follow this and if you don’t have an 8×8 Led Matrix you can follow this and so on.

How to Do Device Monitoring with JavaFX and FXGL

Mon, 11 Jan 2021 10:09:21 +0000

In a previous post “Getting Started with FXGL Game Development” we already have taken a look at the FXGL game development framework developed by Almas Baimagambetov .

But, this game engine can also be used for other use cases. In this post, we will be building a system monitoring dashboard, which can run on a Raspberry Pi. The dashboard can be used to keep an eye on any device that can report its state to a queue. And, for me personally, it finally solves the problem of finding the IP addresses of all my Raspberry Pi’s when my router decided to shuffle them… 😉

Light Up your Christmas Tree with Java and Raspberry Pi

Wed, 23 Dec 2020 09:38:17 +0000

Are you a serious Java-developer looking for a fun project?

Or want to learn something completely new and use your Java-knowledge to control electronic components?

Here we go with this small project to get you introduced to the world of electronics programming!

This post was originally published on “JVM Advent - The JVM Programming Advent Calendar ”, a month-long reading list of diverse Java-related articles. A nice addition to your daily read of Foojay!

JavaFX 3D: A Look Back Through History & Some Experiments

Tue, 27 Oct 2020 09:11:30 +0000

After my virtual conference talk “Java and JavaFX on the Raspberry Pi” at the “Oracle Groundbreakers APAC Virtual Tour 2020” , I got in touch with some people who were working on JavaFX 3D in the past, and were curious how that would behave on the Raspberry Pi.

Only one way to find out! Let’s experiment!

History of JavaFX 3D

JavaFX is an open-source, next-generation Java library for rich client applications. JavaFX started with a focus on 2D UI elements.

Building OpenJDK from GitHub Sources on 64-bit Raspberry Pi

Wed, 21 Oct 2020 06:35:26 +0000

The OpenJDK sources are now fully available and developed on GitHub as a result of Project Skara . Thanks to a lot of work done by the community, the full Java development flow has been migrated to GitHub while keeping the repository history. This process has been described on the GitHub blog .

This also means we are now able to build OpenJDK ourselves from the latest sources, very easily, on any device where we want to use the latest not-yet-released-version.

64-bit Raspbian OS on Raspberry Pi 4 with USB Boot

Mon, 12 Oct 2020 11:14:26 +0000

In a future post, we will be building OpenJDK on a Raspberry Pi.

This post is not really Java-related but a preparation for things to come…

A micro SD card is the default way to add an operating system to the Raspberry Pi. But there is an alternative approach that you need to consider if you want to make your system more reliable. SD cards are not super fast and can get quickly corrupted when you are writing a lot to disc.

Electronics & Micronaut Velocity with Raspberry Pi

Tue, 06 Oct 2020 08:35:45 +0000

In a previous post, we looked at the project “Electronics & Quarkus Qute on Raspberry Pi ” by Igor De Souza .

In this article, we present you another great example of Java on Raspberry Pi created by Igor. It shows how to create a Micronaut Velocity demo using an 8x8 LED matrix display.

Micronaut

Micronaut is a JVM-based framework for building lightweight, modular applications. Developed by OCI , the same company that created Grails , Micronaut is the latest framework designed to make creating microservices quick and easy.

Electronics & Quarkus Qute on Raspberry Pi

Wed, 30 Sep 2020 08:07:13 +0000

The “Hello World” version of electronics programming is a blinking LED. But, in this post, we will go a few steps further and control 8 LEDs inside a number display.

We will do this by taking a closer look at one of the projects in the list “Spectacular Java Projects on the Raspberry Pi ”.

Igor De Souza , Dublin based Principal Big Data Consultant at Oracle, set up an interesting experiment in which he combines a LED number display with the Raspberry Pi and Quarkus.

Spectacular Java Projects on the Raspberry Pi

Wed, 23 Sep 2020 10:38:17 +0000

Thanks to Twitter and LinkedIn, I’ve been in touch with several developers who are doing cool Java stuff on the Raspberry Pi.

Here I want to share a number of projects with you, as they can be an inspiration for all of us to get started with Java development on the Raspberry Pi!

Igor Souza - Kafka on the Raspberry Pi

Igor shared this nice video where he set up a Kafka cluster on Raspberry Pi . He also has a nice example where this is combined with an e-ink display to show real-time bus information . Some of his work is available on GitHub where you can find Kafka and other example code .

Azul Zulu OpenJDK 15 on the Raspberry Pi

Mon, 21 Sep 2020 07:54:30 +0000

For this post I did some experiments with Java 15, reusing the Ubuntu 64bit SD card which was also used for my earlier post " Startup Speed of Spring and Quarkus JARs on the Raspberry Pi ".

That version of Ubuntu comes with OpenJDK 11 pre-installed.

$ java -version
openjdk version "11.0.8" 2020-07-14
OpenJDK Runtime Environment (build 11.0.8+10-post-Ubuntu-0ubuntu120.04)
OpenJDK 64-Bit Server VM (build 11.0.8+10-post-Ubuntu-0ubuntu120.04, mixed mode)

Installing Azul Zulu OpenJDK 15

OpenJDK Java 15 was released on 2020-09-15, check out the Java Version Almanac for more details.

Startup Speed of Spring and Quarkus JARs on the Raspberry Pi

Fri, 18 Sep 2020 09:16:03 +0000

For my book “Getting Started with Java on Raspberry Pi ”, an example was described to store sensors and measurements in an H2-database through REST APIs with a Spring application on the Raspberry Pi.

The application takes some time to start on a Raspberry Pi, and Adam Bien who does the airhacks.fm podcast asked me if I could compare this to a similar Quarkus application, which resulted in some nice results.

Interview: Frank Delporte, Foojay Raspberry Pi Community Manager

Mon, 07 Sep 2020 13:20:38 +0000

Today we’d like to introduce a new community manager for all things Raspberry Pi on foojay: Frank Delporte!

Welcome, Frank! Tell us about yourself. 🙂

Hi, I’m Frank Delporte, living in Belgium. I started programming when I was 10 on my Commodore 64.

I started my professional career as a video editor for television, 25 years ago. I went through all stages from video, multimedia, websites to back-end development using different technologies.

Java 11 & JavaFX 11 on Raspberry Pi with ARMv6 Processor

Fri, 04 Sep 2020 08:00:39 +0000

In a previous post “Installing Java and JavaFX on the Raspberry Pi ”, you can read how to install BellSoft LibericaJDK to be able to run JavaFX applications with a graphical user interface on a Raspberry Pi with ARMv7 or ARMv8 processor.

But this won’t work for some (older) versions of the Raspberry Pi, as these use an ARMv6 processor, which is not compatible with the default OpenJDK 11 that is part of Raspbian OS.

Installing Java and JavaFX on the Raspberry Pi

Tue, 01 Sep 2020 08:32:24 +0000

One of the most read articles on my blog is about the installation of a recent Java on Raspberry Pi (March 13, 2019) , so it was time for an update, which is here republished on foojay.

Disclaimer: this article is only valid for Raspberry Pi’s with an ARMv7 or ARMv8 processor . In the Raspberry Pi specifications table on Wikipedia , you get a clear overview of the Pi-types with this processor: