FLOSS-809

Jonathan: Hey folks, this week, David Ruggles joins me and we talk with Frank Delport about Py4j, a Java library for exposing GPIO and SPI, all kinds of stuff on the Raspberry Pi in Java. You don't want to miss it, so stay tuned. This is Floss Weekly, episode 809, recorded Tuesday, November the 12th. Pi4j, stable and boring on the Raspberry Pi.

It's time for Floss Weekly. That's the show about free, libre, and open source software. I'm your host, Jonathan Bennett, and today we've got something a little different, out of the box. Maybe outside of my comfort zone. But first we have a co host. We have Mr. David Ruggles, the David Factor. Welcome, sir.

Good to be here. I appreciate you kind of popping in at the last moment here saying, Oh, you don't have a co host yet. I can, I can do that. I could be that guy. I very much appreciate it. You're very welcome. Because I think, I, I, it's on me. It was my fault. It was a scheduling snafu that I made. But I think I was going to do the show solo if you hadn't popped in.

So, very much appreciate that.

David: It's going to be interesting. I don't remember which one it was. It was one of the recent ones I was on. It was about Mac and I ended up, oh, Brew! Brew I said I'm not a big Mac guy so many times it became a joke and, you know, now it's, and we ended up calling it the Whopper episode.

So, for this one, I'm not a big Java guy, but I don't know of any funny saying about that, so.

Jonathan: I am here to learn. The question may be, are you a Raspberry Pi guy?

David: Not, I own a couple. And I've run some code on one, but I just, It doesn't fit into my day job, and I don't have enough time for that hobby.

But I love the idea of the Raspberry Pis and that whole ecosystem, and I've done a little bit of Arduino stuff, it's kind of that same you know, software meets hardware. Bye

Jonathan: bye. Yeah, that's, that's the thing about the Raspberry Pi, and so, like, before the Raspberry Pi, there was the, the Beagleboard and Beaglebone, and before that even, there was the Arduino, of course.

If you go even further back, you have things like the BASIC stamp, so this idea has been around for a long time. But the idea of, well, let's take our, our computers that we're used to, that we interact with, and let's give them more ways to reach out and interact with the real world. And that's just the, that's the addictive part for me.

Like that you can, you can hang real hardware. You can, you could, you could do things. And so a lot of times that's turning lights on and off. That's actually where I really got started with some of this was, you know, okay, let's put a relay inside a lamp and then switch the relay. With the way that I first started doing it was the the relay was connected to the arduino The arduino could switch the light back and forth and then the arduino just had a super simple script on it That talked to the local computer That you know so that it could tell the arduino to tell the light to go off and on and then of course You know you you make a web page with a button on it so that you can you know Pull it up from anywhere and turn your light on and off and that's just you know That's geek nirvana.

Like that's that you made it when you could do that So today's guest is Frank Delport, and we're talking about Java on the Raspberry Pi, which, you know, is kind of an interesting thing. So I could, I could see this. With Java, you could do very, very quick sort of prototyping of programs. And there's so many libraries out there.

And then, you know, you bring it to the Raspberry Pi, and it, it is kind of this, like, really easy to get started, really quick prototyping platform, perhaps. So I guess I can see the point of it. Are you familiar with this project at all?

David: I looked at it a little bit enough to have a question about the change in versions.

Okay. That's about as far as I got, so I'll wait for our guests to ask that question.

Jonathan: We will definitely get to that. Let's go ahead and bring bring Frank on. Welcome to the show, sir.

Frank: Hello good evening from Belgium.

Jonathan: Huh. Well, good morning from Oklahoma.

Frank: And thanks for inviting me. You Java lovers.

Jonathan: I've, I've explained it before. My experience with Java happened. Well, one with a much earlier version of Java and two, a much earlier place in my programming career. So I am sure that some of the frustrations that I have would That I had would no longer be things because hopefully I know a little bit better what I'm doing now.

And from what I understand, the Java ecosystem has sort of come along and things are a bit nicer to work with as well.

Frank: Yeah, so people who are listening to this podcast and have a bad feeling about Java, if you're feeling dates from Java 8 or around that time, Please ignore those feelings and, and take a look at, at nowadays Java.

The fun thing is the Java from then still runs on the new run times, but the language has evolved a lot. The run times has evolved a lot of you can write much cleaner codes than you could do. A long time ago and yeah, debugging and the frustrations you have possibly are all gone now with better tooling and, but yeah, everything has evolved as we have so much better IDEs for all languages.

We have a visual studio code for people who want to start coding for free with a very good IDE. What's that? Plugins for all languages. So yeah Java has evolved a lot and, and I hope I can inspire some people who are, who have some frustrations to retry some of these and see what, what has changed.

David: In all fairness, my experience actually is even further back.

It was Java 6, I think the last Java that I touched. Yeah. As soon as I get copious amounts of free time, I will revisit Java. I've committed to that.

Frank: Okay. If you, if you're looking for a starting point, I also write blog posts for fuji. io, which is the website for the friends of OpenJDK, which is a community platform.

And on that Side, I have a small tutorial getting started with Java 30 minutes of video with all the basic functionality of Java which could be a good starting point if, if it's really new to you or you just want to see what the current state is.

Jonathan: Yeah, so let's, let's start with this question that I, I threatened that I was going to ask, and that is, why, why, who, who thought it was a good idea to put Java on the Raspberry Pi?

And of course I asked this very tongue in cheek but I'm sure you, I'm sure you get it a lot. Like, why Java on the Pi?

Frank: Well we go back, I think, about five years, In history, and I was doing Java development at that time for a company in Belgium, Televic Rail, who builds display systems for, for trains and communication systems for trains.

And we were also using Javavix. So those are, Javavix is a graphical user tool for Java. So those were my two tools that I was used to use to, to work with, and I wanted to create a touch based touch screen based application for my son for his drum boot. So it was then nine years old. So a little application on a touch screen where he could start some lights in his drum boot and, and some flushing let strips.

And I wanted to create that with Java and Javavix because those are the tools I know. I wanted to use Raspberry Pis because I had a few of them because I was I'm also doing a Coder Dojo, the coding club for kids. So we have some, some of the stuff laying around and, and, and they say, if you want to learn something new, you should focus on one thing.

And for me, it was the electronics, communicating with. electronics hardware from software. So I needed to use the tools I already knew, Java, Java, Vix, and, and, and Raspberry Pis. I've used that a bit. I used Linux before. So the new thing for me was communicating with, with those devices. And that's how I started with some basic experiments, blinking a LED.

The hello world in, in electronics and I found at that time that there was not that much documentation about running Java on a small PC like the Raspberry Pi. We go five years back. So there were not the Raspberry Pi five we have now, which is a full power device. So we had the Raspberry Pi three, I think at that time.

So I, I needed to find out a lot of stuff and experiment, and that's when I started writing blog posts and, and people who are watching this podcast as a video, they can see my book behind me here on the side. So I ended up writing a book which landed me a new job. So it's, for me, it was a personal journey of, of combining software and hardware.

And Java is my language, the language I use the most and love the most. So that's why I thought that Java on Raspberry Pi is actually a good, good idea. And during that journey, I, I bumped on Pi4j, which is a project which is already I think it started in 2012 a Java library to make it easy for Java developers to communicate with the GPIOs of the Raspberry Pi.

So interact with electronic devices and, and, and, and in those, those last years, I got involved in the, into the Py4j project itself. Thank you. And that's why I'm here to share this message and this love for electronics on the Raspberry Pi.

Jonathan: Yeah. And, and so, you know, with the, with the Pi it's kind of been interesting because the, the, the Linux kernel in general, the Raspberry Pi, it seems has sort of dragged some of these things into the kernel, like not necessarily GPIO access from the kernel, but exposing that to user space.

Like from, from what I can tell, that, that subsystem Was created because of the Raspberry Pi and other devices like it. So how much, how much of this worked when you got involved with Py4j a few years ago? How much of this was...

Episode 809 transcript