Hackaday Podcast Episode 291: Walking In Space, Lead In The Earth, And Atoms Under The DIY Microscope

October 4, 2024 by Al Williams 2 Comments

What have you missed on Hackaday this week? Elliot Williams and Al Williams compare notes on their favorites from the week, and you are invited. The guys may have said too much about the Supercon badge this year — listen in for a few hints about what it will be about.

For hacks, you’ll hear about scanning tunneling microscopes, power management for small Linux systems, and lots of inertial measurement units. The guys talked about a few impossible hacks for consumer electronics, from hacking a laptop, to custom cell phones.

Of course, there are plenty more long-form articles of the week, including a brief history of what can go wrong on a spacewalk and how to get the lead out (of the ground). Don’t forget to take a stab at the What’s That Sound competition and maybe score a sweet Hackaday Podcast T-shirt.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Use this link to teleport a DRM-free MP3 to your location.

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Inside The F-4 Attitude Indicator

September 30, 2024 by Al Williams 10 Comments

[Ken] recently obtained an attitude indicator—sometimes called an artificial horizon—from an F-4 fighter jet. Unlike some indicators, the F-4’s can rotate to show pitch, roll, and yaw, so it moves in three different directions. [Ken] wondered how that could work, so, like any of us, he took it apart to find out.

With the cover off, the device is a marvel of compact design. Then you realize that some of the circuit is inside the ball, so there’s even more than it appears at a quick glance. As you might have guessed, there are two separate slip rings that allow the ball to turn freely without tangling wires. Of course, even if you don’t tangle wires, getting the ball to reflect the aircraft’s orientation is an exercise in control theory, and [Ken] shows us the servo loop that makes it happen. There’s a gyroscope and synchros—sometimes known by the trade name selsyn—to keep everything in the same position.

You have to be amazed by the designers of things like this. Sophisticated both electrically and mechanically, rugged, compact, and able to handle a lot of stress. Good thing it didn’t have to be cheap.

We’ve seen inside an ADI before. If you want to make any of this look simple, check out the mechanical flight computers from the 1950s.

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The Last Sun Sparc Workstation

September 28, 2024 by Al Williams 38 Comments

The truth is, our desktop computers today would have been classed as supercomputers only a few decades ago. There was a time when people who needed real desktop power looked down their noses at anyone with a Mac or a PC with any operating system on it. The workstation crowd used Sun computers. Sun used the Sparc processor, and the machine had specs that are laughable now but were enviable in their day. [RetroBytes] shows off Sun’s final entry in the category, the Ultra 45 from 2007.

Confusingly, the model numbers don’t necessarily increase. The Ultra 80, for example, is an older computer than the 45. Then there were machines like the Ultra 20, 24, 27, and 40 that all used x86 CPUs. A ’45 had one or two UltraSPARC III 64-bit CPUs running at 1.6 GHz and up to a whopping 16 GB of RAM (the one in the video has 8GB). Sure, we see less powerful computers today, but they are usually Chromebooks or very cheap PCs.

The Ultra line started back in 1995 but went underground for a few years with a re-branding. Sun brought the name back in 2005, and the Ultra 45 hit the streets in 2006, only to discontinue the machine in late 2008. According to [RetroBytes], the Sun team knew the Workstation days were numbered and wanted to produce a final awesome workstation. Partially, the reason for sparing few expenses was that anyone who was buying a SPARC workstation in 2006 probably had a reason not to move to cheaper hardware, so you have them over a proverbial barrel.

We liked the CPU cooler, which looked hefty. Honestly, except for the type of CPUs in it, the box could pass itself off as a mid-range desktop tower today with PCI express sockets. The operating system was Sun’s brand of Unix, Solaris, now owned by Oracle.

Sun’s big competitor for a while was Apollo. We’d point out that if all you want is to run Solaris, you don’t need to buy new old hardware.

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Spectroscopy On The Cheap

September 27, 2024 by Al Williams 11 Comments

[Project 326] wanted to know exactly what gas was in some glass tubes. The answer, of course, is to use a spectrometer, but that’s an expensive piece of gear, right? Not really. Sure, these cheap devices aren’t perfect, but they are serviceable and, as the video below shows, there are ways to work around some of the limitations.

The two units in question are “The Little Garden” spectrometer and a TLM-2. Neither are especially sensitive, but both are well under $100, so you can’t expect much. Because the spectrometers were not very sensitive, a 3D printed jig and lens were used to collect more light and block ambient light interference. The jigs also allowed the inclusion of special filters, which enhanced performance quite a bit. The neon bulbs give off the greatest glow when exposed to high voltage. Other bulbs contain things like helium, xenon, and carbon dioxide. There were also tubes with mercury vapor and even deuterium.

We’ll admit it. Not everyone needs a spectrometer, but if you do, there’s a lot of really interesting info on how to get the most out of these cheap devices. Apparently, [Project 326] was frustrated that he couldn’t buy an X-ray spectrometer and has vowed to create one, so we’ll be interested to see how that goes.

Some homebrew spectrometers can get pretty fancy. Of course, there’s more to spectroscopy than just optics.

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3D Printed Jellyfish Lights Up

September 27, 2024 by Al Williams 1 Comment

[Ben] may be 15 years old, but he’s got the knack for 3D printing and artistic mechanical design. When you see his 3D-printed mechanical jellyfish lamp, we think you’ll agree. Honestly, it is hardly fair to call it a lamp. It is really — as [Ben] points out — a kinetic sculpture.

One of the high points of the post is the very detailed documentation. Not only is everything explained, but there is quite a bit of background information on jellyfish, different types of gears, and optimizing 3D prints along with information on how to recreate the sculpture.

There is quite a bit of printing, including the tentacles. There are a few options, like Arduino-controlled LEDs. However, the heart of the operation is a geared motor.

All the design files for 3D printing and the Arduino code are in the post. There’s also a remote control. The design allows you to have different colors for various pieces and easily swap them with a screwdriver.

One major concern was how noisy the thing would be with a spinning motor. According to [Ben], the noise level is about 33 dB, which is about what a whisper sounds like. However, he mentions you could consider using ball bearings, quieter motors, or different types of gears to get the noise down even further.

We imagine this jellyfish will come in at well under $6 million. If you don’t want your jellyfish to be art, maybe you’d prefer one that creates art.

Retro Gadgets: Things Your TV No Longer Needs

September 27, 2024 by Al Williams 62 Comments

It is hard to imagine that a handful of decades ago, TV wasn’t a thing. We’ve talked a few times about the birth of television. After an admittedly slow slow start, it took over like wildfire. Of course, anything that sells millions will spawn accessories. Some may be great. Then there are others.

We wanted to take a nostalgic look back at some of the strange add-ons people used to put on or in their TVs. Sure, VCRs, DVD players, and video game consoles were popular. But we were thinking a little more obscure than that.

Rabbit Ears

Every once in a while, we see an ad or a box in a store touting the ability to get great TV programming for free. Invariably, it is a USB device that lets you watch free streaming channels or it is an antenna. There was a time when nearly all TVs had “rabbit ears” — so called because they made an ~~inverted~~ V on the top of your set.

These dipoles were telescoping and you were supposed to adjust them to fit the TV station you were watching but everyone “knew” that you wanted them as long as possible at all times. Holding one end of them gave it a ground and would give you a major improvement in picture. People also liked to wrap tin foil around the tips. Was it like a capacitive hat? We aren’t sure.

The better rabbit ears had knobs and switches along with multiple elements. If you lived close to a TV station, you probably didn’t need much. If you didn’t, no number of fancy add-ons would likely help you. Continue reading “Retro Gadgets: Things Your TV No Longer Needs” →

Blinking An LED Passively

September 27, 2024 by Al Williams 44 Comments

It is a pretty common first project to use an Arduino (or similar) to blink an LED. Which, of course, brings taunts of: you could have used a 555! You can, of course, also use any sort of oscillator, but [Mustafa] has a different approach. Blinking an LED with three resistors and a capacitor. Ok, ok… one of the resistors is a light-dependent resistor, but still.

In reality, this is a classic relaxation oscillator. The capacitor charges until the LED lights. This, however, causes the capacitor to discharge, which eventually turns off the LED, and the process starts again.

There is one wrinkle that could be considered a feature. In daylight, the capacitor will stay in the off state, so the blinking only occurs in darkness. Of course, the resistor also has to have a sufficient view of the LED. You might use this as a safety light that only works in the dark.

A simple circuit, but it just goes to show that we tend to forget the simple solutions in a world where a computer costs less than a dollar.

Of course, you can get a chip whose sole purpose is to blink LEDs. We always like examples of doing more with less.

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