Frank Delporte, Author of Getting started with Java on the Raspberry Pi

Len: Hi I’m Len Epp from Leanpub, and in this episode of the Frontmatter podcast I’ll be interviewing Frank Delporte.

Based in Passendale, Belgium, Frank is a software developer with over two decades of experience in a number of different areas, including video and multimedia, technical project management, and web programming.

You can follow him on Twitter @FrankDelporte and check out his website at webtechie.be.

Frank is the author of the Leanpub book Getting started with Java on the Raspberry Pi.

In the book, Frank teaches you the power and fun of combining programming and electronics using the popular Raspberry Pi technology. Along the way, he takes the reader through the history of the Java programming language, a set of really interesting interviews with experts, and he also aims to help to make you a better programmer generally.

In this interview, we’re going to talk about Frank’s background and career, professional interests, his book, and at the end we’ll talk about his experience as a self-published author.

So, thank you Frank for being on the Leanpub Frontmatter Podcast.

Frank: Yeah, thank you for inviting me. It’s really great to be here.

Len: Thanks. I always like to start these interviews by asking people for their origin story. So, I was wondering if you could talk a little bit about how you first got interested in technology and computers, and electronics?

Frank: Electronics, yeah. Way back when I was ten, eleven years old, I think we were one of the first schools in Belgium with computers, Commodore 64s. I’m old, yes. That’s almost 40 years ago.

And the fun thing with that Commodore 64 - if you found the right books somewhere in the library or a little shop, you could get some PCBs to attach to your Commodore, and control all the stuff with that. I didn’t know anything about electronics, it’s really true - it’s from books that I learned to do that.

And when I was, I think, fourteen, fifteen years old, I controlled my Lego train with my Commodore 64. That was really the first time I was able to program something, and see the physical effect of it. Not just a program running on computer, it did actually doing something. If a train with a small magnetic sensor was at a certain point, I could stop it. You had this interaction between very basic electronic components and a program, and how will these interact with each other?

As you said, I took the direction of visual editing and multimedia development. It was a time that YouTube didn’t exist yet, but there were CD ROMS. Then we had the challenge to go from analogue video recording to CD ROM. We had this whole conversion flow. Later came websites, and that’s the moment I went back to programming. Creating something, yeah - CD ROM, that was Macromedia at the time. Flash Director, or Bolt by Adobe. You had this whole evolution from static, simple websites. YouTube started, databases came into the picture, catalogues and stuff like that. I went more and more back to this programming.

At a certain point, I joined the Belgian company, Televic, where we created passenger information systems. Screens in a train to show the next station. That’s actually where everything was combined. We had video, we had communication with the website, to bring information to the trains. That’s where I also started working with Java. These services on these trains and on the website were both using Java to control different things, announcements in the trains.

Then I went to another company, Toadi. I made robots, the robot mower. Again, with Java in the back end. Java is since the last ten, fifteen years, my main programming language. Aside from that, ten years ago, I got involved with CoderDojo. I don’t know if you know it? It’s a computer club for kids between six and eighteen. As soon as they can read a bit, they can start programming with Scratch, a really great free tool online. Again - you program something, and you have a cat that starts moving. For children, it’s very attractive. These school dojo clubs are organized by people who do this just as a hobby. They bring their own interest into these clubs.

The clubs I was setting up in Belgium, we had some guys bringing Arduino and Raspberry Pis. Because they had that as a hobby. If you compare that Commodore 64 from many years ago, and Raspberry Pi, it’s the same magic that happens. You can connect things to it. You can have a LED that blinks. If you spend twenty Euros, you have an Arduino and a bunch of LEDs and buttons and resistors and have a lesson - you can make things that start moving or blinking or making sounds. That’s something really fascinating, that - these are very small devices, very inexpensive.

You have a full blown Raspberry Pi, that is 1,000 times - I don’t even know - more performant than my Commodore 64. The most expensive one is 95 Euros. The cheapest one is 15. That’s a full computer, and it’s six centimeters by something. It’s so small and so powerful.

As a Java developer, I wanted to experiment with these boards. The idea was to build some kind of touch screen device for the drum booth for my son. You could have lights going on and off, and LED strips. But I didn’t know anything about it, and that’s the wonders of the internet these days. You can find everything. But still I got blocked. Java, Raspberry PI - not a lot of people are doing that. Some say it’s even a bad idea, and I’m not going to argue with them. Java is just my programming language. I wanted to do it. I used Java. Used Java and things to build a user interface.

Eventually, instead of creating the project, I wrote a book. At first I wrote one article for The MagPi magazine. Then the publisher said, “Can this become a book?” Then we had a long discussion about writing a physical book, a paper book. The discussion was so long that I already started on something called “Leanpub.”

So, I write. Since July, June, just before December, I joined Azul, which is a company providing Java runtimes and services around Java, and optimizing Java for your environment. I am now a technical writer for Azul, improving documentation. So, you could say that the circle is round. I am a programmer. I was interested in writing, now I’m writer interested in programming. I have those two loves that come together at my job, and what I do on my blog.

Len: Thanks very much for sharing that story. There’s actually a lot to unpack there. One of the things I did preparing for this interview, was I listened to a podcast interview you did with airhacks, where you go into - the host of that podcast is much more qualified to talk to you about the sort of technical details of what you did…

Frank: He’s a Java guy, yeah.

Len: … and all stuff you’ve done. I will put a link to that episode in the transcription of this. Because actually you go into detail about the Commodore 64 story. In particular, one of the things I love to talk to people about on the podcast is their experience of technology evolving through time. Talking to people who started back in the day - when you went to the store, and like, “Oh, there’s a book on something, I’ll try that.” It wasn’t often that you had an idea for something, and then you could just Google it and do it. Often you were subject to what was available to you.

You mentioned even now getting blocked. But in those days, when you were fourteen, fifteen, using books or magazines to try and figure things out, if you got blocked, it was hard to get out of that block. There was no Stack Overflow, or anything like that.

I was wondering if you could talk a little bit about what that, about what that experience was like back when you were a teenager trying to confront those kinds of issues.

Frank: That was really my problem. I think at that time you had Elektor, which has published the paper version of my book, already existed. They had this magazine about electronics. I think I had one of those magazines with an advertisement for a book about programming with the Commodore 64, and interacting with electronic components. It was a book in a bundle with that board - a PCB board with eight roulettes [?], so that you could control eight things, like my Lego train.

I live in Belgium. The publisher is from the Netherlands, and that’s just over the border. But at that time, that was a challenge for my father, to buy that book, and send money to the Netherlands. That was really a challenge.

Then the book arrived many weeks later, with a letter that said, “Bere is the book and here is the PCB - but only the PCB. Sorry we don’t have one with all the components and which is assembled.” I never soldered anything. I didn’t know what the resistor was, what the roulette [?] was. I just had a PCB and a list of components.

At the time, you had these electronic shops. We had one where I lived, five kilometers away - so with my bike, I had to go to the shop with my shopping list, and ask this person in the shop, “This is the first time I’m going to do this. Can you explain what I need?” I was sent back home with a full bag of components, a soldering iron - and then it started.

After many days, when my PCB was soldered with all these components, and I plugged it for the first time in my Commodore 64, and I powered it on - I heard this electronic firework-like sound inside my Commodore 64. I was really terrified I had fried my computer. Then I checked again, everything - plugged it in again, and it worked. I was very lucky that I didn’t ruin my computer.

But imagine how this evolved in all these years. Paying something to another country, or the other side of the world is one click away. Finding components, local - I mean, in my case, duckduckgo. You have your components at unbelievable prices. When you started to go to dojo clubs, we wanted to have roulettes [?]. We bought 100 outlets for one Euro and a half, and they were sent for free from China. What world is it that we live in, that you can buy anything with a few clicks? It’s amazing, but it’s terrifying at the same time.

But it opens so many possibilities. The experiments I wanted to do at that time, would now take you half an hour - and a day later, you have all the components in your mailbox. It’s a big evolution.

On the other hand, it was a big adventure to get something done at that time. I don’t know what is best.

Len: It’s really interesting, because one natural thing to think is, “Well, actually, you can get all the clicks, you can get all the searches, you can buy things from anywhere for cheap.” One thing you probably can’t do nowadays like you could back then, was just show up at a store, and have someone talk to you for half an hour, who’s an expert on the things in the store, on how they’re used. That’s pretty rare. But of course, the alternative is - a million YouTube videos, by someone who takes maybe hours to go through a whole project, put a production together and show you how to -

Frank: How to solder, yeah.

Len: Yeah.

Frank: Go to YouTube -

Len: Yeah.

Frank: You’ll find dozens of movies about how to solder something.

Len: Yeah, exactly.

Frank: But it needs that little shop, that electronics shop - it has existed at that same location until that person that had the shop retired.

When I was the same age, you had the Tandy shops. I don’t know if it that still exists in the market. All these shops where I knew, they sold two types of computers. Things evolved. They have much more powerful -

Len: Speaking of -

Frank: Devices, but yeah.

Len: Yeah. Speaking of evolving, your next step - I think a lot of people would probably expect you went into university and did a computer programming degree, or something like a Computer Science degree. But actually you went to film school.

Frank: Yeah.

Len: I was wondering if you could talk a little bit about why you were interested in film school, and what things you learned at film school at that time?

Frank: I’ve always been interested in technical stuff. How do things work? I was the kid that opened every device which was broken. I know how a coffee machine works, because I took some apart when I was a kid.

When I had to choose what to study, then you go to a few schools. I went to [?], they have a very beautiful school with engineering. But I also joined a classmate of me to Brussels, to film school.

When we arrived there, that was in the middle of a park. A little castle. At that time we didn’t notice, but it was falling apart. But it looked special, very special. Inside that castle you had a television studio. What we didn’t know was, it was outdated by twenty years. But it was a very fun environment.

You had three types of film school - two types, sorry. You had the artistic film school, where you become a director. Then you had the other school, where we went - and that wasn’t technical, it was an engineering school. The people who left that school were a cameraman, sound engineer, light engineer, editor. We were really focusing on the technical part of making movies and television.

That’s how I decided to just go to that school. Because it was special, and combined a lot of challenging technologies. How do you make television? How do you make a movie?

To be honest, if I now look back - I would advise myself to go to that engineering degree for electronics or software engineer. But it’s always easy to look back.

When I left school, that was about the time when video editing for television moved from tapes to computer editing. I was one of the first in Belgium to use a computer to edit video. I had to travel around to different studios to demonstrate how this worked. At that time - it was a very big Apple, with a very big case next to it and hard drives. You could predict - if I now click on this and this button for the fourth time, it will crash. So, it was really new times.

But that’s how I went from video editing to making this a small file, so it fits on a CD-ROM - and then even a bigger file, that it fits on the website.

Then you had - DVDs were then also the thing that - making a menu on a DVD that you could select a different part of a business presentation. Not a movie, but a business presentation.

Going to a film school was indeed a challenging option. Also because, there are a lot of candidates to become a television cameraman or video editor. But there’s not a lot of people who eventually get hired. I was lucky to get into this position.

Len: Eventually you made your way into web development as well. I was wondering if you could talk a little bit about what led to that happening?

Frank: Yeah, just out of curiosity and opportunities and luck, and - how do you call it? At that time I was technical chief, or whatever you call it - for a television channel where we did, in the weekends, broadcasting of sport matches. My responsibility was to keep this system alive, and have all these live feeds coming in. But that actually meant that I had one hour of work to start and put everything in place, and at the end, disconnect a few cables, clean up. I had eleven hours in between that I had to be there, but didn’t have a lot of work. I bought my very first laptop, and a book about how you create an HTML page.

Dreamweaver was on there, I think? It was even frontpage at that time, Microsoft FrontPage. A hell of a program, it created a lot of boilerplate that you didn’t need, but you had to find out why it was there. That’s how I created my first websites.

Then I found some customers for that, friends who wanted a website. That became my main job, to develop websites. Very basic at the time. It was the time of the annoying “Skip Intros.” You remember? The Flash animations where you had to sit through if they forgot to put a “Skip Intro” button. You had these whole animations with music - nice in the beginning, annoying after a few times. So, yeah - even those Flash animations, that was many years ago.

Len: Yeah, it was - that was actually a really interesting moment to think about. I mean, like people were figuring out, “What’s the web?” “What should the experience of sitting in front of a screen and watching stuff be?”

A lot of people - I mean, the initial stuff was reading, right? Then came looking at pictures. But when the big media companies started getting websites and stuff like that, they wanted to make - basically, movies - or what have you. You’d go to the website. I’m going to see a little movie. Because that’s what they did. In their view, you were like - it was like a version of watching television, to some extent. They wanted to sort of give you a experience. As you said, if you didn’t have “Skip Intro” buttons, then you were just stuck watching it, when that might not be what you want to do at all. But the idea of having a captive audience that doesn’t have a choice about what you show it, was the idea, in many cases.

Frank: You had this intro movie, before you could enter a website - yes.

Len: Yeah. It’s, actually - it was really interesting that you mentioned Dreamweaver, and stuff like that. That brings back memories of sort of how hard web development seemed, sometimes at the time. It was like these big - I mean, we can talk about technical writing and documentation and stuff like that. But things came with big, huge manuals. The idea of intuitive UI wasn’t really a thing. People almost expected things to be really hard and complex. Otherwise they’d be disappointed that they paid so much for it.

Frank: Well actually, at that time, Adobe really pushed some evolutions in there. Dreamweaver was a really a good tool from the very first time I used it - and coming from FrontPage, I think, that was really, “Oh.” Then, I was also experimenting with databases. I had some customers who wanted to show natural stone tiles, a whole collection of those.

Another one was a light fixture company. They wanted a database behind it. Dreamweaver really made that very easy to understand, how you would need to interact with the database. “Skip Intro” that were Flash animations.

I was really a lover of Flash. Not only for the “Skip Intro” stuff, but also for business presentations. You could build really amazing, beautiful stuff with it. It evolved into complex ActionScripts. If I compared ActionScript and the ease of development with ActionScript, that same experience you have with Java.

They were really from the - yeah, current things. What nowadays Java is, but things you can do for graphical designs - actually already existed with Flash. You could build amazing things. It was - the same application could be executed on different platforms, and on the web.

Until Steve Jobs one day said, “I will never put Flash on an iPad.” That was the beginning of the end for that technology. But, yeah - Adobe evolved into more current directions, and the licenses became a lot more expensive. But if you now look into our software development, and tools evolved into - we have built very great tools you can buy.

But on the other hand, this open source community - now what you can find free - I was just messing around with a picture. I want extra solar panels on my roof, because they say that electricity’s too expensive now. I want to draw on my roof some extra solar panels. There is a Photoshop - someone made a clone of Photoshop which works in the browser. It’s free. It works exactly the same as Photoshop. How well can you make something, it’s incredible. There is an amazing community doing open source there.

That’s also one of the things that I find so amazing about Java. When I started writing my book - you mentioned in the intro I have some interviews. These interviews, they’re Java experts, these are my heroes. I send them a tweet, and they reply. They say, “Oh yeah, of course - no problem. What do you want to know?” Yeah, it keeps amazing me.

Len: You’re touching on something really interesting there, I think, which is that creativity and community go hand-in-hand with technology, in very interesting ways. Coding clubs, like you mentioned, of course, like electronics clubs and stuff like that, can often be very popular. Then when the web came around, people could interact with each other in chatrooms, or whatever.

But then eventually, more sophisticated ways, they could actually introduce - in addition to producing content, like videos and “how to’s” and stuff like that, and just sharing advice - they could build programs together. Which is just amazing. Then when you add open source to that, this self-reproducing feedback loop of productivity and creativity emerges.

That leads me to ask - when did you get into blogging and creating things for other people?

Frank: I always loved to write. In an early, early job, when I was doing website developments, we created a website targeting a pregnant woman, or pregnant couples, to give them tips. We were also pregnant at the time. I started writing about that story. It was a problem pregnancy, so we were a in hospital a lot.

I started writing for my clients. I started blogging. That became my first experience of writing my diary, but then in public.

A few years later, we went to Kazakhstan, because our son is adopted. So, again, that became a story that colleagues and family was interested in. I started writing about that.

Since then, blogging has been a constant, but with a long set of pauses in-between. Whenever something was in my mind, whenever I learnt something that I thought, “Maybe this could be interesting for someone?” That was when I created my own blog. I put it online. I have no clue where it is, this article on my blog, actually. I have to look it up for you now. It goes back to 2007, wow.

Len: Wow.

Frank: It’s two articles about ActionScript and Flex. Apparently, I had an issue. I didn’t find the solution. When I found my solution, I wrote it into these blogs. Those were my first technical blogs.

Then in-between, when I started CoderDojo, I started club seven and eight, I think, in Belgium - now we have over 100. Again, I described, “What do you need to do to start a CoderDojo club?” You have to find a sponsor, a location. Then some documentation about starting to program with Scratch and STEM. And, yeah - and so slowly it became a bit of my playground.

When I do an experiment with the electronics of programming something new, I also keep a text file open. Every link which leads me to a solution, or part of the solution, I keep it.

Most of the time, the first ten links I have to remove again, because they’re wrong, the directions. But at the end I have very short notes, and a few links of what I used to create this thing. Whenever I have some time left, I really like to make that a story again. That’s also the same thing which happened, and eventually led to the book.

I wanted to create the screen control for my son. The first problem was, “How do I run Java with a graphical user interface library? How do I run that on Raspberry Pi?” I didn’t find a lot of tutorials around that. It was a long time that I was using LEDs, and then resistors, and all this stuff. How do you control that with Java from Raspberry Pi? What even is this Raspberry Pi, and what is this pin - and why is there 3.3 volt coming out of it? All these things I had to find out. I just kept a big list of notes.

Len: That’s great. You’ve done a lot of my own podcast host work for me there, by segueing into the next part of the interview, where we talk about your book.

But it’s a very important point though, that the origin stories of projects are like, you had a problem yourself, or you were learning something yourself. Then when you’re done, you’re like, you write the thing that you wished you’d had when you’d started.

Frank: Actually that is the tip for everyone who thinks, “Should I blog?” Yes. Everyone who is a programmer, or any other hobby or project or whatever that you’re doing, and you’re finding a solution that you didn’t read somewhere else, it means that you’ve found something new that someone else also can use, maybe two persons, maybe more? You never know, but -

Len: Yeah, it’s interesting. It goes all the way from the cheesy life hack, to the, like, “best practice at big corporations.” It’s a boring word, but, “documentation” is an incredibly powerful thing.

That thing that you mentioned about having a text file open. I mean, there’s a few things that I wish I could go back and tell my younger self, “Do this.” One of them would be like, “When you figure something out, or do some process for the first time, write it down.” Whatever it is.

In the old days, this used to be harder. But like let’s say I want to change my address when I move? Well, what are all the places that I have to get in touch with? Nowadays what you do is - I use spreadsheets for this stuff often too. It’s like, “When I move,” list all the things, links to all the “change address” things. Links to all the phone numbers if you need to call, stuff like that.

Scale that up to, let’s say you’re working at a company; people come and go from companies. If you come up with a new process or you do something for the first time, write it down, have a corporate wiki or whatever.

It sounds small, but these kinds of things can have huge consequences for productivity, maintaining products. Explaining them to people, and things like that, are the ways that lots of books got started.

On that note specifically, with respect to your book, I was wondering if you could start with answering the question you just asked a moment ago: What is Raspberry Pi?

Frank: Raspberry P is a very small computer. That’s the basic idea.

Raspberry Pi is a company, a foundation in England. Their origin is, “Can we build a computer for everyone, so that everyone is able to get a computer in their house, even if you don’t have any money or just a little bit, can we provide you a computer?”

The very first Raspberry Pi, the idea was, the connector was not a computer screen connector, it was really an analogue signal that you can connect to a TV, the old CRT TV’s.

If you could only afford this little board, you could get started. Because you could connect it to your TV. You don’t need the computer monitor. I think that the starting price then was 25, 35 Euros. It’s about ten centimeters by six, something like that, I think? That was the very first one.

We are now on Raspberry Pi four. The most expensive one is now 95 Euros. But it is a full Linux computer. If you can get the Raspberry Pi operating system, it looks like Windows Mac, open to the desktop, it looks very similar. You can work with any other computer. You have a text editor, you have a web browser.

Of course, it’s not as fast as your $700 laptop. We still need a keyboard, a mouse, a screen, it’s only this little PCB. One of the funny parts of this Raspberry PI, is, in the beginning, they had this processor that they selected. This chip had some extra pins that you could connect electronic components to. They were not going to do anything with it. But then, yeah, during the design, they found out, “Yeah, we have some place on the port, let’s put some pins.” I think there were only 20 something of these pins. “We’ll see what happens with it, what people can do.”

Eventually, I think this has been one of the critical things, the most important things, why this Raspberry Pi became so popular, is you can connect whatever device you want. I have here a CrowPi. It looks like a laptop. You can take out the keyboards, and under the keyboard you have a distance sensor, a motion sensor, an LED screen, an LCD display, twenty-something buttons, a temperature sensor. All these components are all connected to this Raspberry Pi, without the need to wire anything, you can read the temperature in your room, you can detect that someone is moving with his hands above it. It’s not just a computer, it’s an interface. You can connect stuff to it.

Then Raspberry Pi evolved, they also have Raspberry Pi 400, which is this Raspberry Pi four, inside the keyboard. You have a keyboard, there’s a Raspberry Pi inside. It looks like a Commodore 64 which has been on a diet. It’s a bit thinner. But, again, you connect a mouse, you connect a screen, and that’s your computer. Also, it costs 100 Euros, something like that.

Now they have, for people who know Arduino, Raspberry Pi also created a Raspberry Pi Pico, which is also micro-controlled, and costs four dollars, yeah? It’s an amazing device. It’s so powerful. It can connect LED strips to it. You can connect wifi. You have now the Pico, which has wifi on board, six dollars.

These prices are so low, if you want to start experimenting with electronics, with programming on these devices, just leave your PC on the side, don’t blow it up, don’t connect these devices. Do it, to use one of these cheaper things. The idea is, bring affordable computing to anyone in the world.

It’s a bit like what the BBC has done in England with the micro:bit. That was one of the very first, very affordable micro controllers and computers that they brought to schools. Everyone at a certain age got one for free. Raspberry Pi’s a bit related to that. It’s also founded in England.

One problem we have at this moment is a chip shortage around the world. That also affects Raspberry Pi. If you now want a Raspberry Pi, good luck. There are sites who monitor all the other sites who are selling Raspberry Pis, and you are alerted that they are in stock. If you’re lucky, you can buy one.

Len: Wow, that’s fascinating. I hadn’t heard it had affected Raspberry Pi’s. I mean, I’d heard about cars and laundry machines and everything else. But there you go.

One thing I didn’t want to pass over, without actually getting into a true detail, is, you mentioned pins. For people listening who might not be, like they’ve maybe never seen, I think it’s called a “breadboard,” or something like that? For people who are completely unaware of electronics, basically you’ve got a little connection, a physical connection that you make. You can control whether or not there’s basically electricity going through that specific connection.

Frank: Yeah. You have the small PCB. On one side you have two rows of 20 metal pins, one centimeter high, something like that. You don’t even need a breadboard, you could have a small cable, you could plug it in. On the other side you have a LED. Then from the LED, you go back to your ground. There has to be a resistor in-between but -

Len: What’s a LED?

Frank: A “Light Emitting Diode.” that’s a small component,

Len: Oh, an LED, okay.

Frank: LED. A very small component. If you send electricity through it in the right direction, it sends out light. Now these pins, more than 20 of these 40 pins, you can control from software. Either there is zero volt coming out of them, and if you put it on “one,” then becomes 3.3 volts. It’s a digital pin. It’s zero or one. That means if you control it from software and you put 3 volt 3/zero 3 on it, then your LED will go on. Or the other way around, if you put 3 volt 3/zero 3 [?] on it, to a button, for instance, you can read it. Is there voltage on this pin or not? Very simple, with a LED and a button, it’s on or it’s off, right?

Now if you do this very, very fast, then it becomes a communication in a way. You can talk to another chip or another device, like, for instance, a distance sensor. We don’t like to use a distance sensor in electronics to do as a first example. These distance sensors have a few pins. On one pin you have to put for a short time, a voltage, to say, “I want you to measure the distance between the sensor and something above it.” Then it will send back how long. It’s like a bat, a flying bat. They measured the distance with an ultrasound. It reflects. They know how far they are from a wall. It’s the same thing. The sensor will send back for the same time that it’s doing this measurement out for an object.

You have to read, “How long is this 3 volt 3/zero 3 enabled or not?” Then you can calculate for these distances from the sensor. This is a very low value. You have to be very fast with your program. That’s why it’s a nice challenge. You have to do a very strict timing of how you measure values, otherwise you get ones which our out of range, or cannot be right.

These pins, it’s playing with voltages. For people who have been using Arduino or other microcontrollers, you have analogue pins and digital pins in that world, a digital pin is a one or a zero. An analogue pin is between zero and 255. It can be, you can have a range of values. Raspberry Pi is simple, just digital, one or zero, yeah?

It’s not ideal for some electronic components, while Arduino is better. But it’s always a tradeoff, “What do I want to achieve with my project? What do I want to do?” Of course, the solution, you can do the same thing with Raspberry Pi, with another chip in-between. But, yeah, you have to start experimenting.

Len: Exactly. It was exactly that ability to control things, that surprised the people who developed the first Raspberry Pi, as I understand the story? Because, you actually mentioned this at the beginning, I think I read something you wrote about it? Maybe, I forget, on Twitter, or something? But this isn’t back when they first came out. Your son plays the drums. I used to play the drums myself, so I could identify with the story, because drums are really loud. So you built a box or something for your son to play drums in?

Frank: Yeah, yeah.

Len: But what you wanted to do was set up a light, so that he knows when dinner’s ready, or something like that, right? People just started doing really fun things like that.

Frank: There was no sound effect.

Len: But people started doing really fun things like that. They realized, Oh, and I think probably what attracted people too, was that you, by having that on/off, like one or zero control, you get a really direct understanding of the beginnings of information theory and things like that, right? Like, “What can I communicate with on and off states between two things, when I transmit it or receive it?” It just gets you to the heart of computing, in a very tactile way.

Frank: And, yeah, reading a button is very simple. A button is pushed, or it’s not pushed. But then going further. “How can I read something,?” Hlfway, if you want to dim the lights. And, “How do I read this value?” In the drum booth for my son, it’s very simple, I have a Raspberry Pi. On top there are two ports plugged onto the Raspberry Pi, onto these pins. Then I have eight roulettes.

Each roulette, a roulette is - Raspberry Pi only can supply 3 volt 3. But my lights one is 220 volts, the other one is 15. I have different, a strobal scope and LED light, and all these are connected to this roulette, which is, a button, you could say, for doubling this higher power. But my Raspberry Pi can control it, yeah.

Then we have a few LED strips. Those are better controlled with Arduino. The Raspberry Pi is sending a signal to the Arduino, “Now you have to send this pattern to the LED strip.” It’s a bit of a combination of all the different components.

As you said, because I used Java on this Raspberry Pi, Java has a million libraries available for every purpose that you can think of, and one of them is a webserver.

With a few lines of code, you add the webserver to this application, and now from anywhere in the house, I can tell this application, “Put all the lights on red. Let them blink, so my son knows he has to stop playing the drums and come down, and dinner’s on the table.” Because, as you say, drumming can be pretty loud. He drums upstairs, so we don’t have to go up the stairs all the time to tell him to stop drumming.

That was one of my main choices for Java. All the libraries. As I said before, most of them are open source. You can extend your application with a ton of possibilities, and you actually only need a few lines of code.

Len: That’s actually really interesting. That’s something that you go into in a chapter in the book, as well as the history of Java, the programming language, and why you chose it as the language you wanted to use for some of your experimentations, and how useful it can be in so many ways. Of course, it’s your day job as well.

Just in the interests of time, moving onto the last part of the interview. Normally what we would do is, we would talk about your book and your writing process and stuff, but you told that story already at the beginning. It is really interesting, I think, just to make that connection, that the company that you bought that very first book from, is the company that published the paper version of your book. I just wanted to make sure -

Frank: They are the trigger, yes, yes.

Len: People got that. Elektor. It’s E-L-E-K-T-O-R. That’s just a really great closing of the loop.

But since we’ve already talked about that, the last thing I actually wanted to talk to you about, is one fun thing you did in your book, is you had these interviews with experts, but you occasionally have just some thoughts of your own on something. Which is a really great device for giving people a bit of a refresh between chapters.

In one thing, you talk about social media. So, this is a big right turn in the interview. But just before we go, I was wondering if you could talk a little bit about that. Because it’s an interesting story that you tell about your experience and the decision that you made, and why.

Frank: As I said, I’m a big fan of technology, and how tech evolves, and what is new. At a certain point, whatever news service I saw passing, I registered. Everyone who wanted my details, you get them. I went to a conference in Belgium where Aral Balkan was a speaker, and Aral Balkan is one of those programmers who was a hero in Flash. He made amazing Flash animation games, stuff like that. I went to this conference, he was a speaker.

He spoke the dangers of social media, instead of Flash. He is now a social media critic. He even founded a company to build something which is, you own your own data, that’s the main story, yeah. That was really an eye-opener. Because if something is for free, then you are the product being sold. Facebook is free, because they sell your data. Google is free, because they know everything about you, and can target you with advertisements. I wasn’t aware of that before. I didn’t think about that.

At that time, it clicked, and I just started - I haven’t used Gmail and Google since then. I mentioned DuckDuckGo before, that’s my search engine. I still have my Gmail address, but it forwards to my own address. I don’t think I get any email anymore on that one.

On the other hand, I’m addicted to Twitter. Everything I learn, a lot of what I learn is from Twitter. But I am well aware that I am also a product being sold there. My son is twelve, is the age of TikTok, Snapchat, whatever. We should be more aware of what is happening behind the curtains of these companies, I think.

But it’s difficult. It’s a balance. We have Mastodon, which is a great alternative to Twitter, which is, again, open source, managed by the community. But there are not that many people on there, and I don’t find the content that I get from Twitter, so I’m still on, more on Twitter than on Mastodon.

It’s a difficult discussion. I find it hard to tell this story to people; most people just don’t care. They like Facebook. They like getting free stuff. And, yeah, I understand that also.

Len: I’ve had this discussion with a few people on the podcast in the past; it is interesting how - it’s a banal observation, but what seems really great, can turn bad. For example, one guest we had a while ago, he achieved a Twitter fame that became addictive. He would watch how many likes, retweets did he get on every tweet, and go back to it and back to it and back to it, and think about the next one and the next one and the next one. That was the form of toxicity that he encountered.

Of course, for other people it’s getting attacked. But adding onto that, that you’re a product being managed all the time, it is something that, unfortunately, when we say, “Some people just don’t want to think about it,” it’s partly because there really is so much to think about, that you’re just like, “Whatever, I use it for fun, and that’s all I’m going to think about.”

For me, for Twitter specifically, I actually, I learn a lot from Twitter as well. The people I follow are - there’s an old joke, that I think I’ve mentioned here probably too many times, that “Facebook is who you went to high school with, and Twitter is who you wish you went to high school with.”

So on Twitter, I mostly follow journalists and like rock stars, and stuff like that. The guy from Twisted Sister is great on Twitter. And actually watching journalists go back and forth on Twitter, I really like that too. There’s historian Twitter, and there’s journalist Twitter. There’s literary Twitter. There’s all kinds of things like that. You can carve out good niches for yourself, but you can never really get away from the fact that they are using you. You are a product. I mean, it’s particularly hard to not think about how your attention is being managed when you use Facebook, I find.

But anyway, thanks very much for sharing that, that was really great. The whole story, that was really awesome too.

The last question I always like to ask of people on the podcast, if they’re a Leanpub author, is, if there was one magic feature we could build for you, or one terribly awful thing about Leanpub that had you shaking your fist at the screen all the time, that we could fix for you, is there anything that you can think of that you would ask us to do?

Frank: Let me first thank you for how Leanpub works. Being a programmer and being able to write a book in a Markdown file, commit it to GitHub, and get a PDF with the finished book a few minutes later, it’s, wow. I became a paying customer at the time that I was really writing, the six months. Because I just loved to check the changes, to see how this book really grew, where an image was of a page, and it was on the second page, where it shouldn’t be. So I had the line pointing to somewhere else. An amazing thing that you built.

Len: Oh, well, thank you.

Frank: I can remember when I was writing that, I was struggling with the formatting a few times. But then you had this free book, where you had all these explanations of the specific Markdown, of the language that you’re using. I don’t have the page break, is that something new that you added? I just really discovered it just recently that you can actually put like a [page break](https://leanpub.com/markua/read#leanpub-auto-page-breaks. That was something I was missing, I think when I was writing the book, that’s two years ago.

Now I started a few months ago with updating the ebook to a 2022 version. So I discovered that I can now add a page break. That was something I was going to complain about, but that’s all, and I now have the ebook at Leanpub, and I have the paper book with Elektor. It’s not the book that they sell thousands, so they made one print, that’s probably the only one they will create. But that means that print from two years ago, is from two years ago. While the Leanpub book, you can just update it, and there’s a new version, everyone has learned it, being able to have - I’m still also a lover of paper books. I can imagine that people would love to buy the ebook, and maybe also paper version, and maybe something else now?

I bought this book of Bruno Lowagie, Entreprenerd, on Leanpub. I only paid the minimum amount. I was afterwards thinking, “Maybe I should have paid more.”

Going back to my, the thing that I bought, and pay something extra. I don’t know if that’s something which could be added, or which is a good idea? I have no clue.

Len: Thanks very much for sharing all that. That is interesting. When it comes to the feature of page break, I mean, in my head, it’s new. But that could mean it’s been around for a couple of years. It’s one of those things that, I don’t remember the date, it does feel new, but we’ve been doing this for a long time. That was definitely a popular thing to add, so people can manage, particularly where images show up on the PDF version, and stuff like that.

When it comes to print, we do have our Print-Ready PDF output, which people use to publish on print-on-demand services. It’s easy to update the Leanpub produced print ready PDF. You click a button, and you get your PDF.

But when it comes to actually uploading it onto a print-on-demand service, whether it’s Amazon, like KDP, or Ingram, or something like that, how easy it is to update and have that propagate through their system, it depends on the third-party system that you’re using. Updates are doable when you’re using systems or services like that.

When it comes to the last thing you asked, actually, that’s something that’s been a long-standing request that we get from people. Which is basically a tip jar, or something like that.

“Is there any way I can just tip an author?” What we always say is, “Buy the book again.” Then you can archive the second copy in your Leanpub library, or what have you.

But that is something that we’ve been asked for, and we do, I’m not going to say, “plan.” We do intend to do something along those lines at some point. But that’s definitely something people ask for.

It’s actually something, that like, that’s deep Leanpub there, and lessons that we learned, right? Is, people wanting to pay, feeling bad that they didn’t pay more for something. You don’t learn that in MBA school.

Frank: Yes.

Len: That’s not something you’ll hear in Economics 101. But it’s very true, and it’s particularly true in the self-publishing world, in a self-publishing world, where people make 80% royalties - just to boost Leanpub a little bit - we show how much the author earns when you make a purchase. That really helps establish a connection between the reader and the author.

Frank: Also a big thank you for the pricing model. As you say, the 80% - I had published my ebook also on Amazon KDP. I stopped it for two reasons. The low part that you get yourself as a publisher, and that they send you money from all over the world, and my accountant really hates it. You, as Leanpub, pay from one account, one address, that’s clear. Amazon paying from all over the world, from all different monitors, is that called correctly in English?

Len: Sorry, what was,? What was the word?

Frank: You get Yen and you get Euros, and you get dollars,

Len: Oh different currencies, yeah.

Frank: Currencies, yeah, that’s the word. Yes, you get all these different currencies. Then how much they calculated, and accountants hate it. Unluckily, in Belgium, you have to be in order, so it has to go to my accountant. I just stopped Amazon.

I was sick of it, I had enough. I don’t know how much I really made on Amazon, but please go to Leanpub, buy there.

Len: On that note, that’s a great place to end. Thanks again, very much, for being on the podcast and for being a Leanpub author. For anybody interested in this very interesting book, it’s called Getting started with Java on the Raspberry Pi

Frank: Thanks a lot.

Len: Thanks.

As always, thanks to all of you for listening to this episode of the Frontmatter podcast. If you like what you heard, please rate and review it wherever you found it, and if you’d like to be a Leanpub author, please visit our website at leanpub.com.