3D Printed Pi Laptop Honors The Iconic GRiD Compass

January 11, 2021 by Tom Nardi 28 Comments

If you’re familiar with vintage portable computers, you know about the GRiD Compass. Even if you’re not into computers of yesteryear, there’s a good chance you’ve seen a Compass or two without realizing it. From battling xenomorphs in Aliens to making the trip to orbit aboard the Space Shuttle, the trendsetting clamshell computer seemed to be everywhere in the 1980s. While far too expensive for the average consumer to afford back then, its no-compromise design and sleek looks helped lay the groundwork for today’s ubiquitous laptops.

Getting your hands on a working GRiD Compass in 2021 isn’t a whole lot easier than it was in 1982, so [Mike] decided to do the next best thing and build his own. His GRIZ Sextant certainly isn’t a replica, but the family resemblance is strong enough to get the point across. The Raspberry Pi powered machine has a greatly reduced “trunk” section in the back as you might expect, but the overall layout is very similar. The Commodore 64 inspired color scheme is probably the biggest departure from the source material, but it’s hard to argue with the results.

It’s clear at a glance that a lot of thought was put into the external aesthetics of the Sextant, but a peek under the hood shows the internal details are equally impressive. [Mike] tells us he has a background in product design, and it shows. Rather than approaching this project as a one-off creation, he’s clearly taken great pains to ensure the design is as reproducible as possible.

All of the individual components of the 3D printed frame and enclosure have been carefully designed so they’ll fit within the build volume of the average desktop machine. Electronic components are screwed, not glued, to the internal framework; making future repairs and maintenance much easier. When combined with the ample internal volume available, this modular approach should make adding custom hardware a relatively painless process as well.

So when will you be able to build a GRIZ Sextant of your own? Hopefully, very soon. [Mike] says he still needs to work some kinks out of the power supply and finalize how the speakers will get mounted into the case. Once those last tweaks are locked in, he plans to release all the STL files and a complete Bill of Materials. For those who want to get a sneak peek before they start warming up the extruder, he’s also started documenting the assembly of the Sextant on his YouTube channel. Continue reading “3D Printed Pi Laptop Honors The Iconic GRiD Compass” →

Growing Opals In The Lab

January 11, 2021 by Lewin Day 7 Comments

Opals are unique amongst gemstones, being formed from tiny silica nanospheres arranged in precise structures that give them their characteristic shifting color when seen from different angles. [The Thought Emporium] loves a challenge, so set about growing some himself.

It’s not the hardest gemstone synthesis ever, but it’s no cakewalk either. The process requires tetraethyl orthosilicate, or TEOS, which can be difficult to find, but the rest of the chemicals required are commonly available. The initial phase involves mixing the TEOS with reactants to form nanoscale silica spheres in the range of 200-350 nanometers wide. With the spheres in solution, the mixture must then be carefully dried in such a way as to create the right structure to produce opal’s famous color effects. At this stage, industrial producers add further silica to stabilize the matrix, though [The Thought Emporium] wasn’t able to find literature that explained how to do this. Instead, he relied on resin, which while imperfect, did allow the specimens to be stabilised and shown off for the purposes of the video.

The video notes that many of the steps in this process were perfected decades ago, but remain held as trade secrets, making replication an exercise in experimentation. Nonetheless, success was had in producing recognisably opalescent specimens, and we can’t wait to see further refinement of the DIY process.

We’ve seen similar work from [The Thought Emporium] before, exploring structural color and holograms. Video after the break.

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Starlink Satellite Dish X-Rayed To Unlock RF Magic Inside

January 11, 2021 by Tom Nardi 15 Comments

When [Kenneth Keiter] took apart his Starlink dish back in November, he did his best to explain the high-level functionality of the incredibly complex device in a video posted to his YouTube channel. It was a fascinating look at the equipment, but by his own admission, he wasn’t the right person to try and explain the nuances of how the phased array actually functioned. But he knew who could do the technology justice, which is why he shipped the dismembered dish over to [Shahriar Shahramian] of The Signal Path.

Don’t be surprised if you can’t quite wrap your head around his detailed analysis after your first viewing. You’ll probably have a few lingering questions after the second re-watch as well. But that’s OK, as [Shahriar] still has a few of his own. Even after cutting out a section of the dish and putting it under an X-ray, it’s still not completely clear how the SpaceX engineers managed to cram everything into such a tidy package. Though there seems to be no question that the $500 price for the early-access hardware is an absolute steal, all things considered.

The layered antenna works on multiple frequencies.

Most of the video is spent examining the stacked honeycomb construction of the phased antenna array, which as expected, holds a number of RF secrets if you know what to look for. Put simply, there’s no such thing as an insignificant detail to the trained eye. From the carefully sized injection molded spacer sheet that keeps the upper array a specific distance from the RF4-like radome, to the almost microscopic holes that have been bored through each floating patch to maintain equalized air pressure through the stack up, [Shahriar] picks up on fascinating details which might otherwise seem like arbitrary design decisions.

But a visual inspection will only get you so far. Eventually [Shahriar] has to cut out a slice of the PCB so he can fit it into the X-ray machine, but don’t feel too bad, the dish was long dead before he got his hands on it. While he hasn’t yet completed his full analysis, an initial examination indicates that each large IC and the eight chips surrounding it make up a 16 channel beam forming module. Each channel is further split into two RX and TX pairs, which provides the necessary right and left hand polarization. That said, he admits there’s some room for interpretation and that further work would be necessary before any hard conclusions could be made.

Between this RF analysis and the initial overview provided by [Kenneth], we’ve already learned a lot more about this device than many might have expected considering how rare and expensive the hardware is. While we admit it’s not immediately clear what kind of hijinks hardware hackers could get into once this device is fully understood, we’re certainly eager to find out.

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Dangerous Greeting Cards You Probably Shouldn’t Send Anyone

January 11, 2021 by Lewin Day 25 Comments

Regular paper greeting cards are pricey for what they are, and of course the annoying musical variety are even more so. If you really want to go all out, however, you’ve got to go custom made. That’s what [Xyla] and [Ian] did, though we’d stop short of recommending you build or send these to anyone!

Two variants of the “dangerous cards” were built. One repurposed an electric shocking circuit from a handheld buzzer, tucking it inside a shiny Disney greeting card. Using a switch from a musical greeting card, when opened, the shocking circuit is activated. With the circuit connected to aluminium tape electrodes hidden in the shiny foil design, when the user opens the card, they receive a painful shock. The flamethrowing variant was triggered by the same mechanism, though instead sent power to an electric match, shooting a fireball with flash cotton when the card was opened.

These cards make excellent pranks, though we’d be wary about sending them by mail for obvious reasons. We’ve seen [Xyla’s] work before too, with her glowing kayak a particular highlight. Video after the break.

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TabFS Makes Your Browser A File System

January 11, 2021 by Al Williams 11 Comments

Like Unix, old-fashioned Linux has the philosophy that everything should look like a file. That paradigm works well and most of the operating system’s core features follow that pattern. However, many modern additions don’t really treat things as files or, at least, not files you can easily manipulate with the other tools. [Omar Rizwan] has a handy Chrome extension, though, that will make your browser tabs look like part of your file system. Not only is it a novel idea, but it is also surprisingly handy.

The extension feels like a bit of a proof of concept, so installation is a bit rough, but it does work and it allows you to do things that you would otherwise have to write an extension or a sophisticated program to screen scrape which is always less than desirable.

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Ask Hackaday: What’s In Your Fastener Bin?

January 11, 2021 by Dan Maloney 143 Comments

A Saturday afternoon. The work week was done, the household chores were wrapped up, and with almost a week left until Christmas, there was just enough wiggle room to deny that there was still a ton of work left to prepare for that event. It seemed like the perfect time to escape into the shop and knock out a quick project, one that has been on the back burner since at least March. I’m nothing if not skilled in the ways of procrastination.

This was to be a simple project — adding an aluminum plate to a plastic enclosure that would serve as an antenna entry point into my shack. Easy as pie — cut out an rectangle of aluminum, cut and drill a few holes, call it a day. Almost all of my projects start out that way, and almost every time I forget that pretty much every one of those builds goes off the rails at exactly the same point: when I realize that I don’t have the fasteners needed. That’s what happened with this build, which had been going swimmingly up to that point — no major screw-ups, no blood drawn. And so it was off to the hardware store I trundled, looking for the right fasteners to finish the job.

Finding hardware has long been where my productivity goes to die. Even though I live a stone’s throw from at least half a dozen stores, each with a vast selection of hardware and most open weekends and nights, the loss of momentum that results from changing from build-mode to procure-mode has historically been deadly to my projects. I’m sure I’m not the only one who has run into this issue, so the question is: what can a hacker do to prevent having to run out for just the right fasteners?

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Plant Communication Hack Chat

January 11, 2021 by Dan Maloney 12 Comments

Join us on Wednesday, January 13th at noon Pacific for the Plant Communication Hack Chat with Lex Kravitz!

As far as conversation goes, plants are usually a pretty poor choice of partners. Sure, we’ve all heard that talking to you houseplants is supposed to be good for them, but expecting them to talk back in any meaningful way is likely to end in disappointment.

Or is it? For as simple and inanimate as plants appear to be, they actually have a rich set of behaviors. Plants can react to stimuli, moving toward attractants like light and nutrients and away from repellents. Some trees can secrete substances to prevent competitors crowding around them, by preventing their seedlings from ever even taking root. And we’ve known for a long time that plants can communicate with each other, through chemical signaling.

Plants are clearly capable of much more than just sitting there, but is there more to the story? Neuroscientist Lex Kravitz thinks so, which is why he has been wiring up his houseplants to sensitive amplifiers and looking for electrical signals. While the bulk of what we know about plant communications is centered on the chemical signals they send, it could be that there’s an electrical component to their behaviors too. Join us as Lex stops by the Hack Chat to talk about his plant communication experiments, and to see if it may someday be possible to listen in on what your plants are saying about you.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, January 13 at 12:00 PM Pacific time. If time zones have you tied up, 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.

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