Finding The Right Hack Is Half The Battle

Sometimes you just get lucky. I had a project on my list for a long time, and it was one that I had been putting off for a few months now because I loathed one part of what it entailed — sensitive, high-accuracy analog measurement. And then, out of the blue I stumbled on exactly the right trick, and my problems vanished in thin air. Thanks, Internet of Hackers!

The project in question is a low-vacuum regulator for “bagging” fiberglass layups. What I needed was some way to read a pressure sensor and turn on and off a vacuum pump accordingly. The industry-standard vacuum gauges are neat devices, essentially a tiny little strain gauge on a membrane between the vacuum side and the atmosphere side, in a package the size of a dime. (That it’s a strain gauge is foreshadowing, but I didn’t know that at the time.) I bought one for $15 ages ago, and it sat on my desk, awaiting its analog circuitry.

See, the MPX2100 runs on 12 V and puts out a signal around 40 mV on top of a 6 V offset. That voltage level is inconvenient for modern 3.3 V microcontroller ADCs, and the resolution would get clobbered by the 6 V signal if I just put a voltage divider on it. This meant whipping together some kind of instrument amplifier circuit to null out the 6 V and amplify the 40 mV for the ADC. The circuits I found online all called for 1% resistors in values I didn’t have, and mildly special op-amps. No fun, for me at least. So there it sat.

Picture of sketchy-looking vacuum apparatus.
Cut the blue wire or the red wire? HX711 module and pressure sensor on the left.

Until I ran into this project that machetes through the analog jungle with one part, and it happened to be one I had on hand. A vacuum pressure sensor is a strain gauge, set up like a Wheatstone bridge, just like you would use for weighing something with a load cell. The solution? A load-cell ADC chip, the HX711, found in every cheap scale or online for under a buck. The only other trick was finding a low-voltage pressure sensor to work with it, but that turns out to be easy as well, and I had one delivered in two days.

In all, this project took months of foot-dragging, but only a few clicks and five minutes of soldering once I got the right idea. The industrial applications and manufacturers’ app notes all make sense if you are making hundreds or millions of these devices, where the one-time cost of prototyping up the hard bits gets amortized, but the hacker solution of using a weight-scale chip was just the ticket for a one-off. That just goes to show how useful sharing our tips and tricks can be — you won’t get this from the industry. So send us your success stories, and your useful failures too, and Read More Hackaday!

Pick Up The Ball And Run With It

Once in a while we get to glimpse how people build on each other’s work in unexpected and interesting ways. So it is with the GateBoy project, a gate-level emulator built from die shots of the original Game Boy processor. The thing is, [Austin Appleby] didn’t have to start by decapping and taking photos of the chip. He didn’t even have to make his own schematics by reverse engineering those structures. Someone else had already done that and made it available for others to use. A couple of years back, [Furrtek] started manually tracing out the DMG chip and posted schematics to the DMG-CPU-Inside repo, kindly licensing it as CC-BY-SA 4.0 to let people know how they can use the info.

But playing Game Boy games isn’t actually the end game of [Austin’s] meticulous gate-level recreation. He’s using it to build “a set of programming tools that can bridge between the C/C++ universe used by software and the Verilog/VHDL universe used by hardware.” A new tool has been born, not for gaming, but for converting a meta language that assigns four-letter codes to gate structures (somewhat reminiscent of DNA sequences) and will eventually convert them to your choice of C++ or a Hardware Description Language for use with FPGAs.

The open source community is playing four-dimensional football. Each project moves the ball downfield, but some of them add an additional goal in an alternate hardware universe — advancing the aims of both (like finding and fixing some errors in [Furrtek’s] original schematics).

Of course the real challenge is getting the word out that these projects exist and can be useful for something you’re working on. For instance, [Neumi’s] depth sounding rowboat allows an individual to make detailed depth maps of lakes, rivers, and the like. It was in the comments that the OpenSeaMap project was brought up — a site working to create crowd sourced waterway charts. It’s the perfect place for [Neumi] to get inspiration, and help move that ball toward a set of goals.

How do we get the word out so more of these connections happen? We’ll do our part here at Hackaday. But it’s the well-document and thoughtfully-licensed projects that set the up playing field in the first place.

99% Inspiration, 99% Perspiration, And 99% Collaboration

I was watching an oldish TEDx talk with Rodney Mullen, probably the most innovative street skater ever, but that’s not the point, and it’s not his best talk either. Along the way, he makes a claim that ideas — in particular the idea that a particular skateboard trick is even possible — are the most important thing.

His experience, travelling around the world on skateboard tours, is that there are millions of kids who are talented enough that when they see a video demonstrating that a particular trick idea is possible, they can replicate it in short order. Not because the video showed them how, but because it expanded their mind’s-eye view of what is possible. They were primed, and so what pushed them over the edge was the inspiration.

On the other side of the street, we’ve got Thomas Edison and his “1% inspiration, 99% perspiration” routine. Edison famously tried a bazillion filament recipes before settling on tungsten, and attributes his success to “putting his time in” or “good old-fashioned hard work” or similar. So who’s right?

The inventor of Casper Slide and the phonograph are both right. Rodney is taking it for granted that these kids have put their time in; they are skaters after all, they skate. He doesn’t see the 99% perspiration because it is the natural background, while the inspiration flashes out in Eureka moments.

Similarly, Thomas E. way underestimates inspiration. He’s already fixated on this novel idea to take an arc lamp and contain it in a glass envelope — that’s what he’s spending all of his perspiration on, after all. But without that key inspiration, all he’d be is sweaty.

And they’re also both wrong! They’re both missing a third ingredient: collaboration. Certainly Mullen, who spent his life hanging out with other skaters, teaching them what he knows, and learning from them in turn, wouldn’t say the community of skaters didn’t shape him. Even in the loner’s sport of skating, nobody is alone. And Edison? His company profited greatly from broader advances in science, and the scientific literature. Menlo Park existed to take bright, well-trained minds and put them all in one place, sharing, teaching, and working together. It embodied the idea of collaborative innovation, and that’s where some of his best work was done.

So I’m with Isaac Newton, “standing on the shoulders of giants“. Success is 99% collaboration. This leaves us with one problem: the percentages don’t add up. But that’s alright by me.

Printing Yoda Heads: Re-Makers Riffing!

We had a comment recently from a nasty little troll (gasp! on the Internet!). The claim was that most makers are really just “copiers” because they’re not doing original work, whatever that would mean, but instead just re-making projects that other people have already done. People who print other peoples’ 3D models, or use other peoples’ hardware or software modules are necessarily not being creative. Debunking a cheap troll isn’t enough because, on deeper reflection, I’m guilty of the same generic sentiment; that feeling that copying other people’s work isn’t as worthy as making your own. And I think that’s wrong!

In the 3D printing world in particular, I’m guilty of dismissively classifying projects as “Yoda Heads”. About ten years ago, [chylld] uploaded a clean, high-res model of Yoda to Thingiverse, and everyone printed it out. Heck, my wife still has hers on her desk; and alone this is proof that straight-up copying has worth, because it made a sweet little gift. After a while, Yoda gave way to Baby Groots, and strangely enough we’re back to Yoda again, but it’s Baby Yoda now. Continue reading “Printing Yoda Heads: Re-Makers Riffing!”

Why You Need To Finish

Mike and I were talking about an interesting smart-glasses hack on the podcast. This was one of those projects where, even if you don’t need a pair of glasses with LEDs on them to help you navigate around, you just couldn’t help but marvel at a lot of the little design choices made throughout.

For instance, I love the way the flex PCB is made to do double duty by wrapping around the battery and forming a battery holder. This struck me as one of those quintessential hacks that only occurs to you because you need it. Necessity is the mother of invention, and all that. There was a problem, how to fit a battery holder in the tiny space, and a set of resources that included a flex PCB substrate. Cleverly mashing that all together ended up with a novel solution. This wouldn’t occur to you if you were just sitting at the beach; you’d have to be designing something electronic, space-constrained, and on a flex PCB to come up with this.

Mike made an offhand comment about how sometimes you just need to finish a project for the good ideas and clever solutions that you’ll come up with along the way, and I think this battery holder example drives that point home. I can’t count the number of my projects that may or may not have been dumb in retrospect, but along the way I came up with a little trick that I’ll end up using in many further projects, outliving the original application.

Finishing up a project on principle is a reasonable goal just on its own. But when the process of seeing something to conclusion is the generator of new and interesting challenges and solutions, it’s even more valuable. So if you’re stuck on a project, and not sure you want to take it all the way, consider if the journey itself could be the destination, and look at it as an opportunity to come up with that next long-lasting trick.

Bad News: Arecibo

If you read the newsletter last week, you heard me wondering aloud if the damage to Arecibo Observatory had crossed the threshold into where it’s no longer economically viable to keep it running, and the sad news has just come in and the battle for Arecibo has been lost. We said we’d shed a tear, and here we are. Sic transit gloria mundi. Here’s hoping something cooler replaces it!

Harnessing Your Creativity Hack Chat

Join us on Wednesday, November 18th at noon Pacific for the Harnessing Your Creativity Hack Chat with Leo Fernekes!

(Note: this Hack Chat was rescheduled from 10/14/2020.)

You’re sitting at your bench, surrounded by the tools of the trade — meters and scopes, power supplies and hand tools, and a well-stocked parts bin. Your breadboard is ready, your fingers are itching to build, and you’ve got everything you need to get started, but — nothing happens. Something is missing, and if you’re like many of us, it’s the one thing you can’t get from eBay or Amazon: the creative spark that makes innovation happen.

Creativity is one of those things that’s difficult to describe, and is often noticed most when it’s absent. Hardware hacking requires great buckets of creativity, and it’s not always possible to count on it being there exactly when it’s called for. It would be great if you could somehow reduce creativity to practice and making it something as easy to source for every project as any other commodity.

While Leo Fernekes hasn’t exactly commoditized creativity, judging from the breadth of projects on his YouTube channel, he’s got a pretty good system for turning ideas into creations. We’ve featured a few of his builds on our pages, like a discrete transistor digital clock, the last continuity tester you’ll ever need, and his somewhat unconventional breadboarding techniques. Leo’s not afraid to fail and share the lessons learned, either.

His projects, though, aren’t the whole story here: it’s his process that we’re going to discuss. Leo joins us for this Hack Chat to poke at the creative process and see what can be done to remain rigorous and systematic in your approach but still make the process creative and flexible. Join us with your questions about finding the inspiration you need to turn parts and skills into finished projects that really innovate.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, November 18 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Continue reading “Harnessing Your Creativity Hack Chat”

Get Over Your Fears

Some projects are just too complex, that’s for sure. But I’d be willing to bet that some things you think are too difficult actually aren’t, and it may be that all you need to get over your personal hurdle is a good demonstration. Here come three cases in point.

I was looking at the new Raspberry Pi Compute Module last weekend. They have a whole bunch of high-speed traces: things like Gigabit Ethernet, HDMI, and those crazy-fast SDI serial camera interfaces. I have no experience in high-speed design and layout at all, and frankly it gives me the willies. But the Raspberries also shipped me an IO demo board, and concomitant KiCAD design files, with the review board. Looking at it, they were just wires — maybe pairwise length-matched and impedance controlled — but also just wires. Opening up the KiCAD board file and clicking on the traces just like I do with my own designs, I’m a lot less scared. That was a revelation for me.

In a great writeup of his experience building ten different Linux single-board-computers from scratch, Jay Carlson had a similar effect on me. I would never have considered breaking out the hotplate for some CPU-and-DRAM action, and I’ve never had to lay out a PCB with a high density BGA chip before either. I’m not quite into Dunning-Kruger territory yet; I still have a healthy respect for the layout intricacies in fanning out a tight BGA CPU into a DRAM. But Jay’s frank assessments of what is easy and what is hard make it all seem within the realm of the doable.

As Mike and I were talking on the podcast about Jay’s work, Mike came clean about his fear of BGAs. I’ve done enough reflow-plate soldering, with parts that have a lead pitch that’s a factor of two finer than the 0.8 mm pitch BGAs in question, so it doesn’t seem implausible to me. And I’m 100% sure Mike could pull it off too, but he is in need of a BGA guru. Any good hobbyist videos out there?

Being a nerdy type, I’m much more focused on the knowledge and the inspiration, but maybe the courage is equally important — at least I think I undervalue it. I don’t need to lay out HDMI lines, or build a from-scratch Linux box, but I am no longer afraid that I couldn’t, and that’s because I’ve seen detailed examples of fellow hackers who’ve done the same. I might not get it right on the first shot, but I’m not afraid to try, and I wouldn’t have said the same before looking over other folks’ shoulders. Forza e corragio!