Ham Radio Memes In The 1970s

If you have a fondness for old and unusual ham gear, [Saveitforparts] has a great video (see below) about a Robot slow scan receiver he found at a junk store.  Slow scan or SSTV is a way to send pictures via low-bandwidth audio, such as you often find on the ham bands. The idea is you take a picture, send some squeaks and blips over the air, and in about 8 or 10 seconds, a single frame of video shows up at the receiver. Hams aren’t the only ones who used it. The Apollo missions used an SSTV system in some cases, too.

I’ve been a ham radio operator for a very long time. When I first heard about SSTV, I thought it sounded cool that you could be talking to someone and then show them a picture of your station or your dog or your kids. But when I looked into it, the reality was far different. In the pre-internet days, SSTV-equipped hams hung out on a handful of watering hole frequencies and basically just sent memes and selfies to each other. Everyone would take turns, but there wasn’t really any conversation.

This actually still goes on, but the hardware isn’t a big deal anymore. The Robot in the video had to decode the signal from audio and store the image somehow. On old gear — some of it homebrew — it was simply persistent phosphor that would eventually fade, but, of course, eventually, images were stored in some form of digital memory. These days, you are likely to use a PC soundcard to both send and receive the necessary audio.

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Human AI Pin marketing picture. (Credting: Humane)

The AI Pin: A Smart Body Camera That Wants To Compete With Smartphones

Seeking to shake up the smartphone market, Humane introduced its ‘AI Pin’, which at first glance looks like someone put a very stylish body camera on their chest. There’s no display, only the 13 MP camera and some other optics visible above what turns out to be a touch panel, which is its main gesture-based input method, while it’s affixed to one’s clothing using either a magnet on the other side of the fabric, a wireless powerbank or a clip. Inside the unit you find a Qualcomm octa-core processor with 4 GB of RAM and 32 GB of eMMC storage, running a custom Android-based ‘Cosmos’ OS.

The AI Pin home screen, demonstrating why hand palms are poor projection surfaces. (Credit: Humane)
The AI Pin home screen, demonstrating why hand palms are poor projection surfaces. (Credit: Humane)

There is also a monochrome (teal) 720p laser projector built-in that provides something of a screen experience, albeit with the expectation that you use your hand (or presumably any other suitable surface) to render it visible. From the PR video it is quite clear that visibility of the projection is highly variable, with much of the text often not remotely legible, or only after some squinting. The hand-based gestures to control the UI (tilting to indicate a direction, touching thumb & index finger together to confirm) are somewhat of a novelty, though this may get tiresome after a day.

An article by [Ron Amadeo] over at Ars Technica also takes a look at the device, where the lack of an app ecosystem is pointed out, as well as the need for a mandatory internet connection (via T-Mobile). Presumably this always-on ‘feature’ is where the ‘AI’ part comes in, as the device has some voice assistant functionality, which seems to rely heavily on remote servers. As a result, this ends up being a quirky device with no third-party app support for a price tag of $700 + the $25/month for online service. Not to mention that people may look a bit odd at you walking around with a body camera-like thing on your chest that you keep rubbing and holding your hand in front of.

To be fair, it’s not often that we see something more quaint in this space come out than Google Glass, now many years ago.

A Mysterious 6502 Apple 2 Simulator

Nice, visual simulators of CPUs such as the 6502 are usually made much later and with more modern tooling than what they simulate. But what if that wasn’t the case? What if a simulator runs on the very hardware it’s simulating?

This is what [Tea Leaves] stumbled upon when he found a mysterious disk with only “APL6502.SIM” on it. [Tea Leaves] demonstrates the simulator with a basic 6502 assembly program, revealing an animated, beautiful Apple 2 simulator that actually runs on the Apple 2! The simulator shows all the major components of a 6502 and actually animates the complete data flow of an instruction.

But why is this mysterious? It’s mysterious because – a “hello” program aside – it’s the only thing on the disk! Not so much as a single clue as to where it came from. [Tea Leaves] finds out where it comes from, including incorrectly copied disk images and a revelation at the end.

Video after the break.
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Neopixels? Try Liquid Nitrogen To Color Shift Your LEDs Instead

If you’re like us, you’ve never spent a second thinking about what happens when you dunk an ordinary LED into liquid nitrogen. That’s too bad because as it turns out, the results are pretty interesting and actually give us a little bit of a look at the quantum world.

The LED fun that [Sebastian] over at Baltic Lab demonstrates in the video below starts with a bright yellow LED and a beaker full of liquid nitrogen. Lowering the powered LED into the nitrogen changes the color of the light from yellow to green, an effect that reverses as the LED is withdrawn and starts to warm up again. There’s no apparent damage to the LED either, although we suppose that repeated thermal cycles might be detrimental at some point. The color change is quite rapid, and seems to also result in a general increase in the LED’s intensity, although that could be an optical illusion; our eyes are most sensitive in the greenish wavelengths, after all.

So why does this happen? [Sebastian] goes into some detail about that, and this is where quantum physics comes into it. The color of an LED is a property of the bandgap of the semiconductor material. Bandgap is just the difference in energy between electrons in the valence band (the energy levels electrons end up at when excited) and the conduction band (the energy levels they start at.) There’s no bandgap in conductive materials — the two bands overlap — while insulators have a huge bandgap and semiconductors have a narrow gap. Bandgap is also dependent on temperature; it increases with decreasing temperature, with different amounts for different semiconductors, but not observably so over normal temperature ranges. But liquid nitrogen is cold enough for the shift to be dramatically visible.

We’d love to see the color shift associated with other cryogens, or see what happens with a blue LED. Want to try this but don’t have any liquid nitrogen? Make some yourself!

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Pimp The Potentiometer

Sometimes, a hack isn’t really about the technology but about the logistics. If we asked you to light up an LED using an Arduino, there’s a good chance you’d know exactly how to do that. How about a bunch of LEDs? Simple. Now turn on LEDs proportional to an input voltage. A little harder, but nothing that you probably haven’t done a million times. Finally, arrange the LEDs in an attractive circle around a potentiometer. Wait, how are you going to do that? [Upir] shows us a ready-made ring light for just this purpose and you can see the beautiful thing in the video below.

We made the LED things sound slightly easier than it is. The ring light has 31 LEDs but only 12 pins, so there is some multiplexing going on. The modules come in pairs for about $20, so not a throwaway part, but they will really dress up anything that needs a knob of any kind.

Naturally, it doesn’t matter what you use to drive the LEDs. You could track a pot or a rotary encoder. Or you could show microphone levels or something else. After all, it is just a bunch of LEDs. For that matter, they’d probably make a good pair of robot eyes. Let us know what you want to use them for in the comments.

If your significant other is a little geeky, you might want a different kind of ring light. We couldn’t help but wish the LEDs on the ring were addressable. That would open up a world of interesting possibilities while reducing the pin count, too.

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Supercon And Soylent Green

The 2023 Hackaday Supercon is all done and dusted, and we’re still catching up on our sleep. I couldn’t ask everyone, but a great time was had by everyone I talked to. It’s honestly a very special crowd that shows up in Pasadena every November, and it’s really the attendees who make it what it is. We just provide the platform to watch you shine. Thank you all!

It all started out on Friday with an open day of chilling out and badge experimentation. Well, chill for those of you who didn’t have a bug in their badge code, anyway. But thanks to some very keen observation and fantastic bug reports by attendees, Al and I figured out what we’d done and pushed a fix out to all 300 of the badges that were given out on the first day. And thanks to the remaining 200 folks who walked in the next day, who fixed their own badges at Tom’s Flashing Station.

From then on, it was one great talk after another, punctuated by badge hacks and all the other crazy stuff that people brought along with them to show off. For me, one of the highlights was on Sunday morning, as the Lightning Talks gave people who were there a chance to get up and talk about whatever for seven minutes. And subjects ranged from a mad explosive propane balloon party, to Scotty Allen’s experience with a bad concussion and how he recovered, to a deep dive into the world of LED strands and soft sculptures from our go-to guru of blinkiness, Debra [Geek Mom] Ansell.

Supercon first-timer Katie [Smalls] Connell gave a phenomenal talk about her wearable LED art things, Spritelights. These are far from simple art pieces, being a combination of medical adhesive, home-mixed Galinstan – a metal alloy that stays flexible at human body temperature, and soon even flexible printed batteries. That this whole project hit us without warning from out of the audience just made it more impressive.

And these were just the folks who stepped up on stage. The true story of Supercon also belongs to all the smaller conversations and personal demos taking place in the alley or by the coffee stand. Who knows how many great ideas were hatched, or at least seeds planted?

So as always, thank you all for coming and bringing your passions along with. Just like Soylent Green, Supercon is made of people, and it wouldn’t be half as yummy without you. See you all next year. And if you’re thinking of joining us, get your tickets early and/or submit a talk proposal when the time comes around. You won’t meet a more warm and welcoming bunch of nerds anywhere.

NVIDIA Trains Custom AI To Assist Chip Designers

AI is big news lately, but as with all new technology moves, it’s important to pierce through the hype. Recent news about NVIDIA creating a custom large language model (LLM) called ChipNeMo to assist in chip design is tailor-made for breathless hyperbole, so it’s refreshing to read exactly how such a thing is genuinely useful.

ChipNeMo is trained on the highly specific domain of semiconductor design via internal code repositories, documentation, and more. The result is a vast 43-billion parameter LLM running on a single A100 GPU that actually plays no direct role in designing chips, but focuses instead on making designers’ jobs easier.

For example, it turns out that senior designers spend a lot of time answering questions from junior designers. If a junior designer can ask ChipNeMo a question like “what does signal x from memory unit y do?” and that saves a senior designer’s time, then NVIDIA says the tool is already worth it. In addition, it turns out another big time sink for designers is dealing with bugs. Bugs are extensively documented in a variety of ways, and designers spend a lot of time reading documentation just to grasp the basics of a particular bug. Acting as a smart interface to such narrowly-focused repositories is something a tool like ChipNeMo excels at, because it can provide not just summaries but also concrete references and sources. Saving developer time in this way is a clear and easy win.

It’s an internal tool and part research project, but it’s easy to see the benefits ChipNeMo can bring. Using LLMs trained on internal information for internal use is something organizations have experimented with (for example, Mozilla did so, while explaining how to do it for yourself) but it’s interesting to see a clear roadmap to assisting developers in concrete ways.