A Great Resource For The Would-Be Pinball Machine Builder

Those of us beyond a certain age will very likely have some fond memories of many an hour spent and pocket money devoured feeding the local arcade pinball machine. At one time they seemed to be pretty much everywhere, but sadly, these days they seem to have largely fallen out of favour and are becoming more of speciality to be specifically sought out. Apart from a few random ones turning up — there’s a fun Frankenstein-themed machine in the Mary Shelley Museum in Bath, England — a trip to a local amusement arcade is often pretty disappointing, with modern arcade machines just not quite scratching that itch anymore, if you ask us. So what’s an old-school hacker to do, but learn how to build a machine from scratch, just the way we want it? A great resource for this is the excellent Pinball Makers site, which shows quite a few different platforms to build upon and a whole ton of resources and guides to help you along the way.

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Learning Electronics By Just Doing It

Learning anything new, especially so broad and far reaching as electronics, can be hard. [IMSAI Guy] knows this because he gets asked regularly “how do I learn electronics?” Many of you reading this will have a few ideas to pass along (and we encourage you to share your take on it in the comments below) but there is an even greater number of people who are asking the same question, and [IMSAI Guy]’s take on it is one that this particular Hackaday writer can relate to.

The ARRL Handbook can be found at hamfests, radio clubs, libraries, or at arrl.org

According to [IMSAI Guy], an excellent place to start is the ARRL Handbook. The ARRL Handbook is an electronics and RF engineering guide published by the Amateur Radio Relay League in the US. It’s a wonderful reference, and past editions can be had very inexpensively and are every bit as handy. Many hams will have a copy they could be talked out of, and you can likely find one at your local library. Where to start in the Handbook, then?

[IMSAI Guy] recommend starting with whatever catches your fancy. As an example, he starts with Op Amps, and rather than diving straight into the math of how they work or even worrying to much about what they are- he just builds a circuit and then plays with it to intrinsically understand how it works, a “learn by doing” approach that he has found extremely helpful just as many of us have. We also appreciated is very straightforward approach to the math: Don’t bother with it unless you need to for some reason, and definitely don’t start by learning it first.

In fact, that same reasoning is applied to any subject: Learn it as you need it, and don’t start by learning but rather by doing. The learning will come on its own! Be sure to check out the entire video and let us know what you think, and how you approached learning electronics. Thanks to [cliff] for the great Tip!

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Bass Guitar Gets Shapeshifting Pickups

Electric guitars were the hip new thing back in the mid-century. The electrification of the common and portable guitar opened up a lot of avenues in terms of sound and technique. Specifically, the use of the pickup, an electromagnetic device which converts the vibrations of the guitar strings into electrical signals, increased the number of ways that a musician can alter the guitar’s sound on-the-fly. Some guitars have several rows of pickups which can be used in any number of ways, but this custom guitar has a single pickup which can be moved around the guitar’s body instead.

[Breno] was gifted this Dolphin bass guitar to start learning after years of playing a regular guitar, and while they aren’t known for high-quality instruments this guitar seemed to play and sound well enough to attempt this modification. First, a hole had to be cut all the way through the guitar’s body in order to accommodate the build. The pickup for this guitar is then mounted on two rods which allow it to move in various positions along the strings, and a second set of adjustments can be made to bring the pickups closer or further away from the strings. Some additional custom circuitry was added to control it and also to handle the volume and tone knobs, and while this was being added [Breno] and his friend [Arthur] decided this would be a great time to build some effects into the guitar’s now-custom electronics as well.

While this was largely a project for [Breno] to understand in greater depth the effect of moving the pickups around an electric guitar, the finished product looks ready to play some live shows. The addition of some extras like the effects really adds some punch to this guitar and it looks to be completely original. The nearest thing we could find is this guitar which uses hot-swappable pickups but even those are mounted in fixed locations.

Designing Electronics That Work

[Hunter Scott] who has graced these pages a fair few times, has been working on electronics startups for the past ten years or so, and has picked up a fair bit of experience with designing and building hardware. Those of us in this business seem to learn the same lessons, quite often the hard way; we call it experience. Wouldn’t it be nice to get up that learning curve a little quicker, get our hardware out there working sooner with less pain, due to not falling into the same old traps those before us already know about? The problem with the less experienced engineer is not their lack of talent, how quickly they can learn, nor how much work they can get done in a day, but simply that they don’t know what they don’t know. There’s no shame in that, it’s just a fact of life. [Hunter] presents for us, the Guide to Designing Electronics that Work.

The book starts at the beginning. The beginning of the engineering process that is; requirements capturing, specifications, test planning and schedule prediction. This part is hard to do right, and this is where the real experience shows. The next section moves onto component selection and prototyping advice, with some great practical advice to sidestep some annoying production issues. Next there’s the obvious section on schematic and layout with plenty of handy tips to help you to that all important final layout. Do not underestimate how hard this latter part is, there is plenty of difficulty in getting a good performing, minimal sized layout, especially if RF applications are involved.

The last few sections cover costing, fabrication and testing. These are difficult topics to learn, if up till now all you’ve done is build prototypes and one-offs. These are the areas where many a kickstarter engineer has fallen flat.

Designing Electronics That Work doesn’t profess to be totally complete, nor have the answer to everything, but as the basis for deeper learning and getting the young engineer on their way to a manufacturable product, it is a very good starting point in our opinion.

The book has been around a little while, and the latest version is available for download right now, on a pay what-you-want basis, so give it a read and you might learn a thing or two, we’re pretty confident it won’t be time wasted!

Treasure Hunting With A Handful Of Common Components

Sometimes simpler is better — when you don’t need the the computational power of an onboard microcontroller, it’s often best to rely on a simple circuit to get the job done. With cheap Raspberry Pis and ESP32s all over the place, it can be easy to forget that many simpler projects can be completed without a single line of code (and with the ongoing chip shortage, it may be more important now than ever to remember that).

[mircemk] had the right idea when he built his simple induction-balance metal detector. It uses a couple of 555 timers, transistors, and passives to sense the presence of metallic objects via a coil of wire. He was able to detect a coin up to 15 cm away, and larger objects at 60cm — not bad for a pile of components you probably have in your bench’s spare parts drawer right now! The detector selectivity can be tuned by a couple of potentiometers, and in true metal detector fashion, it has a buzzer to loudly blare at you once it’s found something (along with a LED, in case the buzzer gets too annoying).

All in all, this metal detector looks like a terribly fun project — one perfectly suited to beginners and more seasoned hackers alike. It serves as a great reminder that not every project needs WiFi or an OLED display to be useful, but don’t let that stop you from overdoing things! If touchscreens are more your speed, [mircemk] has got you covered with a smartphone-integrated version as well.

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Building Blocks: Relating Mechanical Elements To Electronic Components

Ask any electronics hobbyist or professional what the simplest building blocks of electronic circuits are, and they’ll undoubtedly say resistors, capacitors, and inductors. Ask a mechanically-inclined person the same question about their field and the answer will probably be less straightforward. Springs would make the list for sure, but then… hmm. Maybe gears? 80/20 aluminum extrusions?

As it turns out, there are a handful of fundamental building blocks in the mechanisms world, and they’re functionally very similar, and mathematically identical, to the Big Three found in electrical engineering.

Mechanical Equivalents

Before we look at the components themselves, let’s step back a moment and think about voltage and current. Voltage is a potential difference between two points in a circuit, sometimes called electromotive force (EMF). It turns out that EMF is an apt term for it, because it is roughly analogous to, well, force. Voltage describes how “hard” electrons are being “pushed” in a circuit. In much the same vein, current describes the rate of electric charge flow. Continue reading “Building Blocks: Relating Mechanical Elements To Electronic Components”

Portrait Of A Digital Weapon

Over the years, artists have been creating art depicting weapons of mass destruction, war and human conflict. But the weapons of war, and the theatres of operation are changing in the 21st century. The outcome of many future conflicts will surely depend on digital warriors, huddled over their computer screens, punching on their keyboards and maneuvering joysticks, or using devious methods to infect computers to disable or destroy infrastructure. How does an artist give physical form to an unseen, virtual digital weapon? That is the question which inspired [Mac Pierce] to create his latest Portrait of a Digital Weapon.

[Mac]’s art piece is a physical depiction of a virtual digital weapon, a nation-state cyber attack. When activated, this piece displays the full code of the Stuxnet virus, a worm that partially disabled Iran’s nuclear fuel production facility at Natanz around 2008. Continue reading “Portrait Of A Digital Weapon”