Author: Al Williams

4443 Articles

Low Res Arduino Thermal Camera

August 15, 2023 by 10 Comments

Do you know how you see those cheap telescopes at the department store? The box has beautiful pictures that probably came from the Hubble. What you will see is somewhat different. You have to carefully look at [upir’s] Arduino thermal camera project because it intersperses pictures of what you expect an 8×8 sensor will produce with images produced by a much better camera.

The actual project — watch the video below — is undoubtedly neat. An inexpensive 8×8 IR sensor and an 8X8 LED panel join to form a crude but usable thermal camera.

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A Speaker With Dancing Ferrofluid

August 14, 2023 by 2 Comments

A speaker project isn’t usually very different, but we couldn’t help but notice [Electronoob’s] latest speaker not for its audio performance but because it features dancing ferrofluid and is an unusual work of art. The housing is 3D printed and includes some translucent portions for LEDs.You can see and hear the speaker at work in the video below.

Apparently, not all ferrofluid is created equal. You can get just the fluid, but then you have to work up some sort of carrier fluid. You can also get the material already in a glass with a carrier fluid, which is a better option. Apparently, you can also get cheap material that is little more than iron filings suspended in a liquid. That’s not really ferrofluid.

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Linux Kernel From First Principles

August 13, 2023 by 13 Comments

Want to learn the internals of the Linux kernel? Version 6.5-rc5 has about 36 million lines of code in it, so good luck! [Seiya] has a different approach. Go back to the beginning and examine the 0.01 version of the kernel. Now you are talking about 10,000 lines and, removing comments and blanks, way less.

Sure, some things have changed, but the core ideas are the same. [Seiya] reports, “Reading V0.01 was really for me. It was like visiting Computer History Museum in Mountainview…”

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Inside A Cordless Soldering Station

August 12, 2023 by 17 Comments

There was a time when soldering stations were unusual in hobby labs. These days, inexpensive stations are everywhere. [Kerry Wong] looks at the TS1C station, which is tiny and cordless. As he points out, cordless irons are not new, but modern battery technology has made them much more practical. However, this iron doesn’t actually have a battery.

The iron has a large 750 Farad supercapacitor. This has advantages and disadvantages. On the plus side, a supercapacitor charges quickly and doesn’t get weaker with each charging cycle like a conventional battery. On the minus side, the large capacitor makes the unit bulky compared to normal irons. [Kerry] notes that it is ergonomic, though, and he felt comfortable holding it. Also, the supercapacitor limits the amount of charge available while soldering.

It is somewhat of a balance, though. If you want to take the iron and climb a tower, you might be very interested in a longer running time. But if you return the unit to the base every few minutes, the fast charging of the cap will compensate for the lower capacity, and you’ll probably never notice it go flat.

The iron itself doesn’t display any data. The display is on the base, meaning the devices must be paired via Bluetooth. It also requires a PD-enabled USB-C connection, so you can’t just wire it to a battery. You can plug a power supply right into the iron if you prefer, but you still can’t use a simple power connection.

Of course, you assume it does an adequate job of soldering. We wanted to see inside! And [Kerry] didn’t disappoint. If you want to see soldering, skip to about the 10-minute marker. The teardown starts at around 16 minutes.

Honestly, for the bench, we’d probably stick with a wired iron. You don’t always want a base and a PD power supply for a portable iron. But if you absolutely hate cords, this could be a reasonable answer. We’ve seen another review of this iron that didn’t like the plastic casings. Maybe it is like Jedi and lightsabers: you should just build your own.

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Arbitrary Waveforms On The Cheap

August 12, 2023 by 26 Comments

A signal generator that can produce the usual sine, square, and triangle waves is handy and has been a staple of electronic benches for decades. Being able to craft custom signals opens up new horizons, but historically, these instruments were expensive. The price has come down, though, and [Rishin Goswami] made a 5 MHz 8-bit signal generator with 131K data points of arbitrary waveform for a low price: about $20. If you want to spend a bit more, you can improve the output DAC and op amps, but even that should cost well under $100, all in.

This is one of those projects that seems easy until you start digging into it. For example, storing some points and generating signals using any microcontroller isn’t a big deal. But minimizing jitter and maximizing speed with a conventional processor is difficult. That’s why [Rishin] uses a Raspberry Pi Pico. The programmable I/O units are perfect for generating waveform data fast and reliably. You can see the project go through its paces in the video below.

The Pi streams data to an 8-bit DAC. However, it would be easy to improve resolution with a different converter. The DAC0808 also limits the instrument’s sample rate. The processor could likely go much faster if it had a DAC accommodating higher speeds.

This is just a proof-of-concept, so don’t expect fancy GUIs or the ability to import spreadsheets. You control the device from a command-line-like interface. Still, a good example of how to take advantage of the Pi’s hardware. We took a shot at a similar device nearly a decade ago. Those programmable I/O blocks are finding uses in some surprising applications.

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Throw FreeCAD Some Curves

August 12, 2023 by 43 Comments

[Mango Jelly] got a question from someone trying to model a phone box with a complex curved roof. We have to admit that when we saw it, we knew it would be hard to model well. Naturally, there are several ways it could be one, but [Mango Jelly] used the curves workbench in FreeCAD to produce a wireframe of the shape, and you can see how that works in the video below.

The curve bench didn’t sound familiar to us, and that’s because it is an add-on workbench. He starts with a sketch of a curve, constrained to be symmetrical. Then the draft workbench allowed a rotation to convert the curve into a nice skeleton of the curved roof.

The curves workbench can create a Gordon surface over that skeleton. You can extrude that into a solid object. There are still some details to add, though, and you’ll see how each part of the roof takes shape.

Watching videos like this reminds us that we use a small fraction of what FreeCAD can do. You’ll probably pick up at least one tip from this video. If you need a quick basic tutorial, try the one from [NovaSpirit]. Or, try a longer one.

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A Little Bit Of Science History Repeating Itself: Boyle’s List

August 11, 2023 by 24 Comments

In a recent blog post, [Benjamin Breen] makes an interesting case that 2023 might go down in history as the start of a scientific revolution, and that’s even if LK-99 turns out to be a dud. He points to several biomedical, quantum computing, and nuclear fusion news items this year as proof.

However, we aren’t as convinced that these things are here to stay. Sure, LK-99 was debunked pretty quickly, but we swim in press releases about new battery technologies, and new computer advances that we never hear about again. He does mention that we aren’t alone in thinking that as [Tyler Cowen] coined the phrase “Great Stagnation” to refer to the decline in disruptive tech since 1945. Still, [Benjamin] argues that people never know when they live through a scientific revolution and that the rate of science isn’t as important as the impact of it.

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