If you made something blink, and now it’s time for you to make something move, something like a point-to-a-satellite tracker is a great idea. [Farid] made this moving arrow that always points at the ISS, and documented it nicely to boot.

And there’s a little bit of everything here, from orbital mechanics and fetching the two-line elements (TLE) from the web, to writing the code to translate that into the tabletop machine’s coordinate system. It looks like [Farid] hadn’t done much 3D CAD before, so he got a chance to stretch those muscles too. Finally, it served as an introduction to resource-constrained programming: “This was the first time I’ve had to think about the size of a compiled binary – the most frustrating part was figuring out that using a C++ stringstream was adding too much code to my binary.”

[Farid] is learning a lot here, and you might too. For instance, using pencil lead (graphite) as a lubricant on sliding 3D-printed parts is new to us, but makes sense. We’ll have to try that out.

And while this is a simple desktop tracker, with a lot more mechanical design, the same basics could be put to real use for pointing a receiver dish. Of course, who says you need fancy motors and computers to point a satellite dish anyway? If you work on your arm muscles a bit, you could become the satellite pointer.

[Ben Eater]’s breadboard 6502 computer is no stranger to these parts, so it was a bit of a surprise that when [Mark] wrote in asking us if we’d covered [Ben]’s getting MS BASIC running on the breadboard, that our answer was “no”. Well, that changes today!

This is a three-part video series, documenting how [Ben Eater] ports a 1977 version of MS BASIC to his 6502-based computer. The first video is all about just getting the BASIC up and working. It’s full of detail about how MS BASIC adapts to different architectures on the inside, and [Ben] essentially defines his own along the way.

Once he has BASIC working, the next two videos are about making it work not just with the serial terminal that he has attached, but also with the LCD display peripheral he has plugged into the breadboard. BASIC fans will not be surprised to see that it’s all about using POKE. But that ends up being to slow, so he extends it out with his own LCDPRINT command written in assembly.

Now that he can write a character to the LCD, he wants to be able to pass it a string: LCDPRINT “Hello world”. But that requires his command to be able to parse a string, and this has him diving down the rabbit hole into how MS BASIC parses strings, handles evals, and so on. If you want to know how MS BASIC works on the inside, this is the video for you. This video makes a lot of use of wozmon, which seems an almost ideal tool for this kind of low-level poking around.

All of this is done in [Ben]’s very well rehearsed, accessible, but pulling-no-punches style. Get ready to nerd out. All three of the videos are embedded just below the break.

While it’s not the Altair BASIC that Bill himself was writing about last week, it’s probably a direct descendent, and reading about the Altair version was what spurred [Mark Stevens] to send us the tip. Thanks!

If you’re living your life right, you probably know what as MOSFET is. But do you know the MESFET? They are like the faster, uninsulated, Schottky version of a MOSFET, and they used to rule the roost in radio-frequency (RF) silicon. But if you’re like us, and you have never heard of a MESFET, then give this phenomenal video by [Asianometry] a watch. In it, among other things, he explains how the shrinking feature size in CMOS made RF chips cheap, which brought you the modern cellphone as we know it.

The basic overview is that in the 1960s, most high-frequency stuff had to be done with discrete parts because the bipolar-junction semiconductors of the time were just too slow. At this time, MOSFETs were just becoming manufacturable, but were even slower still. The MESFET, without its insulating oxide layer between the metal and the silicon, had less capacitance, and switched faster. When silicon feature sizes got small enough that you could do gigahertz work with them, the MESFET was the tech of choice.

As late as the 1980s, you’d find MESFETs in radio devices. At this time, the feature size of the gates and the thickness of the oxide layer in MOSFETs kept them out of the game. But as CPU manufacturers pushed CMOS theses features smaller, not only did we get chips like the 8086 and 80386, two of Intel’s earliest CMOS designs, but the tech started getting fast enough for RF. And the world never looked back.

If you’re interested in the history of the modern monolithic RF ICs, definitely give the 18-minute video a watch. (You can skip the first three or so if you’re already a radio head.) If you just want to build some radio circuits, this fantastic talk from [Michael Ossmann] at the first-ever Supercon will make you an RF design hero. His secrets? Among them, making the most of exactly these modern everything-in-one-chip RF ICs so that you don’t have to think about that side of things too hard.

Thanks [Stephen] for the tip!

If you flew or drove anything remote controlled until the last few years, chances are very good that you’d be using some faceless corporation’s equipment and radio protocols. But recently, open-source options have taken over the market, at least among the enthusiast core who are into squeezing every last bit of performance out of their gear. So why not take it one step further and roll your own complete system?

Apparently, that’s what [Malcolm Messiter] was thinking when, during the COVID lockdowns, he started his own RC project that he’s calling LockDownRadioControl. The result covers the entire stack, from the protocol to the transmitter and receiver hardware, even to the software that runs it all. The 3D-printed remote sports a Teensy 4.1 and off-the-shelf radio modules on the inside, and premium FrSky hardware on the outside. He’s even got an extensive folder of sound effects that the controller can play to alert you. It’s very complete. Heck, the transmitter even has a game of Pong implemented so that you can keep yourself amused when it’s too rainy to go flying.

Of course, as we alluded to in the beginning, there is a healthy commercial infrastructure and community around other open-source RC projects, namely ExpressLRS and OpenTX, and you can buy gear that runs those software straight out of the box, but it never hurts to have alternatives. And nothing is easier to customize and start hacking on than something you built yourself, so maybe [Malcolm]’s full-stack RC solution is right for you? Either way, it’s certainly impressive for a lockdown project, and evidence of time well spent.

Thanks [Malcolm] for sending that one in!

[Morten] works very fast. He has already designed, fabbed, populated, and tested a breakout board for the new tiniest microcontroller on the market, and he’s even made a video about it, embedded below.

You might have heard about this new TI ARM Cortex MO micro on these very pages, where we asked you what you’d do with this grain-of-rice-sized chunk of thinking sand. (The number one answer was “sneeze and lose it in the carpet”.)

From the video, it looks like [Morten] would design a breakout board using Kicad 8, populate it, get it blinking, and then use its I2C lines to make a simple digital thermometer demo. In the video, he shows how he worked with the part, from making a custom footprint to spending quite a while nudging it into place before soldering it carefully down.

But he nailed it on the first try, and honestly it doesn’t look nearly as intimidating as we’d feared, mostly because of the two-row layout of the balls. It actually looks easy enough to fan out. Because you can’t inspect the soldering work underneath the chip, he broke out all of the lines to a header to make it quick to check for shorts between those tiny little balls. Smart.

We love to see people trying out the newest hotness. Let us know down in the comments what new parts you’re trying out.

Thanks [Clint] for the tip!

If you’re on the US East Coast, you should head on over to Wall, NJ and check out the Vintage Computer Festival East. After all, [Brian Kernighan] is going to be there. Yes, that [Brian Kernighan].

Events are actually well underway, and you’ve already missed the first few TRS-80 Color Computer programming workshops, but rest assured that they’re going on all weekend. If you’re from the other side of the retrocomputing fence, namely the C64 side, you’ve also got a lot to look forward to, because the theme this year is “The Sounds of Retro” which means that your favorite chiptune chips will be getting a workout.

[Tom Nardi] went to VCF East last year, so if you’re on the fence, just have a look at his writeup and you’ll probably hop in your car, or like us, wish you could. If when you do end up going, let us know how it was in the comments!

We ran a story about a wall-mounted plotter bot this week, Mural. It’s a simple, but very well implemented, take on a theme that we’ve seen over and over again in various forms. Two lines, or in this case timing belts, hang the bot on a wall, and two motors drive it around. Maybe a servo pulls the pen in and out, but that’s about it. The rest is motor driving and code.

We were thinking about the first such bot we’ve ever seen, and couldn’t come up with anything earlier than Hektor, a spray-painting version of this idea by [Juerg Lehni]. And since then, it’s reappeared in numerous variations.

Some implementations mount the motors on the wall, some on the bot. There are various geometries and refinements to try to make the system behave more like a simple Cartesian one, but in the end, you always have to deal with a little bit of geometry, or just relish the not-quite-straight lines. (We have yet to see an implementation that maps out the nonlinearities using a webcam, for instance, but that would be cool.) If you’re feeling particularly reductionist, you can even do away with the pen-lifter entirely and simply draw everything as a connected line, Etch-a-Sketch style. Maslow CNC swaps out the pen for a router, and cuts wood.

What I love about this family of wall-plotter bots is that none of them are identical, but they all clearly share the same fundamental idea. You certainly wouldn’t call any one of them a “copy” of another, but they’re all related, like riffing off of the same piece of music, or painting the same haystack in different lighting conditions: robot jazz, or a study in various mechanical implementations of the same core concept. The collection of all wall bots is more than the sum of its parts, and you can learn something from each one. Have you made yours yet?

(Fantastic plotter-bot art by [Sarah Petkus] from her write-up ten years ago!)

Suppose that you want to get rid of a whole lot of mosquitoes with a quadcopter drone by chopping them up in the rotor blades. If you had really good eyesight and pretty amazing piloting skills, you could maybe fly the drone yourself, but honestly this looks like it should be automated. [Alex Toussaint] took us on a tour of how far he has gotten toward that goal in his amazingly broad-ranging 2024 Superconference talk. (Embedded below.)

The end result is an amazing 380-element phased sonar array that allows him to detect the location of mosquitoes in mid-air, identifying them by their particular micro-doppler return signature. It’s an amazing gadget called LeSonar2, that he has open-sourced, and that doubtless has many other applications at the tweak of an algorithm.

Rolling back in time a little bit, the talk starts off with [Alex]’s thoughts about self-guiding drones in general. For obstacle avoidance, you might think of using a camera, but they can be heavy and require a lot of expensive computation. [Alex] favored ultrasonic range finding. But then an array of ultrasonic range finders could locate smaller objects and more precisely than the single ranger that you probably have in mind. This got [Alex] into beamforming and he built an early prototype, which we’ve actually covered in the past. If you’re into this sort of thing, the talk contains a very nice description of the necessary DSP.

[Alex]’s big breakthrough, though, came with shrinking down the ultrasonic receivers. The angular resolution that you can resolve with a beam-forming array is limited by the distance between the microphone elements, and traditional ultrasonic devices like we use in cars are kinda bulky. So here comes a hack: the TDK T3902 MEMS microphones work just fine up into the ultrasound range, even though they’re designed for human hearing. Combining 380 of these in a very tightly packed array, and pushing all of their parallel data into an FPGA for computation, lead to the LeSonar2. Bigger transducers put out ultrasound pulses, the FPGA does some very intense filtering and combining of the output of each microphone, and the resulting 3D range data is sent out over USB.

After a marvelous demo of the device, we get to the end-game application: finding and identifying mosquitoes in mid-air. If you don’t want to kill flies, wasps, bees, or other useful pollinators while eradicating the tiny little bloodsuckers that are the drone’s target, you need to be able to not only locate bugs, but discriminate mosquitoes from the others.

For this, he uses the micro-doppler signatures that the different wing beats of the various insects put out. Wasps have a very wide-band doppler echo – their relatively long and thin wings are moving slower at the roots than at the tips. Flies, on the other hand, have stubbier wings, and emit a tighter echo signal. The mosquito signal is even tighter.

If you told us that you could use sonar to detect mosquitoes at a distance of a few meters, much less locate them and differentiate them from their other insect brethren, we would have thought that it was impossible. But [Alex] and his team are building these devices, and you can even build one yourself if you want. So watch the talk, learn about phased arrays, and start daydreaming about what you would use something like this for.

It all started with a gift idea: a star-field lamp in the form of a concrete sphere with lightpipes poking out where the stars are, lit up from the inside by LEDs. When you’re making one of these, maybe-just-maybe you’d be willing to drill a thousand holes and fit a thousand little plastic rods, but by the time you’re making a second, it’s time to build a machine to do the work for you.

So maybe we quibble with the channel name “Unnecessary Automation,” but we won’t quibble with the results. It’s a machine that orients a sphere, drills the hole, inserts the plastic wire, glues it together with a UV-curing glue, and then trims the end off. And if you like crazy machines, it’s a beauty.

The video goes through all of the design thoughts in detail, but it’s when it comes time to build the machine that the extra-clever bits emerge. For instance, [UA] used a custom 3D-printed peristaltic pump to push the glue out. Taking the disadvantage of peristaltic pumps – that they pulse – as an advantage, a custom housing was designed that dispensed the right amount between the rollers. The rolling glue dispenser mechanism tips up and back to prevent drips.

There are tons of other project-specific hacks here, from the form on the inside of the sphere that simplifies optic bundling and routing to the clever use of a razor blade as a spring. Give it a watch if you find yourself designing your own wacky machines. We think Rube Goldberg would approve. Check out this video for a more software-orientated take on fiber-optic displays.

[Niklas Roy] obviously had a great time building this generative art cabinet that puts you in the role of the curator – ever-changing images show on the screen, but it’s only when you put your money in that it prints yours out, stamps it for authenticity, and cuts it off the paper roll with a mechanical box cutter.

If you like fun machines, you should absolutely go check out the video (embedded below without resorting to YouTube!). The LCD screen has been stripped of its backlight, allowing you to verify that the plot exactly matches the screen by staring through it. The screen flashes red for a sec, and your art is then dispensed. It’s lovely mechatronic theater. We also dig the “progress bar” that is represented by how much of your one Euro’s worth of art it has plotted so far. And it seems to track perfectly; Bill Gates could learn something from watching this. Be sure to check out the build log to see how it all came together.

You’d be forgiven if you expected some AI to be behind the scenes these days, but the algorithm is custom designed by [Niklas] himself, ironically adding to the sense of humanity behind it all. It takes the Unix epoch timestamp as the seed to generate a whole bunch of points, then it connects them together. Each piece is unique, but of course it’s also reproducible, given the timestamp. We’re not sure where this all lies in the current debates about authenticity and ownership of art, but that’s for the comment section.

If you want to see more of [Niklas]’s work, well this isn’t the first time his contraptions have graced our pages. But just last weekend at Hackaday Europe was the first time that he’s ever given us a talk, and it’s entertaining and beautiful. Go check that out next.

We just got back from Hackaday Europe last weekend, and we’re still coming down off the high. It was great to be surrounded by so many crazy, bright, and crazy-bright folks all sharing what they are pouring their creative energy into. The talks were great, and the discussions and impromptu collaborations have added dramatically to our stack of to-do projects. (Thanks?) Badges were hacked, stories were shared, and a good time was had by all.

At the event, we were approached by someone who wanted to know if we could replicate something like Hackaday Europe in a different location, one where there just isn’t as vibrant a hacking scene. And the answer, of course, was maybe, but probably not.

It’s not that we don’t try to put on a good show, bring along fun schwag, and schedule up a nice location. But it’s the crowd of people who attend who make a Hackaday event a Hackaday event. Without you all, it just wouldn’t work.

So in that spirit, thanks to everyone who attended, and who brought along their passions and projects! It was great to see you all, and we’ll do it again soon.

Coming straight to the point: [Ron Hinton] is significantly braver than we are. Or maybe he was just in a worse situation. His historic Acer K385s laptop suffered what we learned is called vinegar syndrome, which is a breakdown in the polarizers that make the LCD work. So he bit the bullet and decided to open up the LCD stack and replace what he could.

Nothing says “no user serviceable parts inside” quite like those foil-and-glue sealed packages, but that didn’t stop [Ron]. Razor blades, patience, and an eye ever watchful for the connectors that are seemingly everywhere, and absolutely critical, got the screen disassembled. Installation of the new polarizers was similarly fiddly.

In the end, it looks like the showstopper to getting a perfect result is that technology has moved on, and these older screens apparently used a phase correction layer between the polarizers, which might be difficult to source these days. (Anyone have more detail on that? We looked around and came up empty.)

This laptop may not be in the pantheon of holy-grail retrocomputers, but that’s exactly what makes it a good candidate for practicing such tricky repair work, and the result is a readable LCD screen on an otherwise broken old laptop, so that counts as a win in our book.

If you want to see an even more adventurous repair effort that ended in glorious failure, check out [Jan Mrázek]’s hack where he tries to convert a color LCD screen to monochrome, inclusive of scraping off the liquid crystals! You learn a lot by taking things apart, of course, but you learn even more by building it up from first principles. If you haven’t seen [Ben Krasnow]’s series on a completely DIY LCD screen, ITO-sputtering and all, then you’ve got some quality video time ahead of you.