Do you remember the fourth-place winner in the 2022 Hackaday Prize? If it’s slipped your mind, that’s okay—it was Boondock Echo. It was a radio project that aimed to make it easy to record and playback conversations from two-way radio communications. The project was entered via Hackaday.io, the judges dug it, and it was one of the top projects of that year’s competition.
Sound chips from back in the day were capable of much more than a few beeps and boops, and [InazumaDenki] proves it in a video recreating recognizable real-world sounds with the AY-3-8910, a chip that was in everything from arcade games to home computers. Results are a bit mixed but it’s surprising how versatile a vintage sound chip that first came out in the late 70s is capable of, with the right configuration.
Recreating a sound begins by analyzing a spectrograph.
Chips like the AY-3-8910 work at a low level, and rely on being driven with the right inputs to generate something useful. It can generate up to three independent square-wave tones, but with the right approach and setup that’s enough to get outputs of varying recognizability for a pedestrian signal, bird call, jackhammer, and referee’s whistle.
To recreate a sound [InazumaDenki] begins by analyzing a recording with a spectrogram, which is a visual representation of frequency changes over time. Because real-world sounds consist of more than just one frequency (and the AY-3-8910 can only do three at once), this is how [InazumaDenki] chooses what frequencies to play, and when. The limitations make it an imperfect reproduction, but as you can hear for yourself, it can certainly be enough to do the job.
How does one go about actually programming the AY-3-8910? Happily there’s a handy Arduino AY3891x library by [Andreas Taylor] that makes it about as simple as can be to explore this part’s capabilities for yourself.
If you think retro-styled sound synthesis might fit into your next project, keep in mind that just about any modern microcontrollers has more than enough capability to do things like 80s-style speech synthesis entirely in software.
If there’s an enduring image of how large steel structures used to be made, it’s probably the hot riveting process. You’ve probably seen grainy old black-and-white films of a riveting gang — universally men in bib overalls with no more safety equipment than a cigarette, heating rivets to red heat in a forge and tossing them up to the riveters with a pair of tongs. There, the rivet is caught with a metal funnel or even a gloved hand, slipped into a waiting hole in a flange connecting a beam to a column, and beaten into submission by a pair of men with pneumatic hammers.
Dirty, hot, and dangerous though the work was, hot riveted joints were a practical and proven way to join members together in steel structures, and chances are good that any commercial building that dates from before the 1960s or so has at least some riveted joints. But times change and technology marches on, and riveted joints largely fell out of fashion in the construction trades in favor of bolted connections. Riveting crews of three or more men were replaced by a single ironworker making hundreds of predictable and precisely tensioned connections, resulting in better joints at lower costs.
Bolted joints being torqued to specs with an electric wrench might not have the flair of red-hot rivets flying around the job site, but they certainly have a lot of engineering behind them. And as it turns out, the secret to turning bolting into a one-person job is mostly in the bolt itself.
If Apple has a reputation for anything other than decent hardware and excellent industrial design, it’s for selling its products at extremely inflated prices. But there are some alternatives if you want the Apple experience on the cheap. Buying their hardware a few years out of date of course is one way to avoid the bulk of the depreciation, but at the extreme end is this working Mac clone that cost just $14.
This build relies on the fact that modern microcontrollers absolutely blow away the computing power available to the average consumer in the 1980s. To emulate the Macintosh 128K, this build uses nothing more powerful than a Raspberry Pi Pico. There’s a little bit more to it than that, though, since this build also replicates the feel of the screen of the era as well. Using a “hat” for the Pi Pico from [Ron’s Computer Videos] lets the Pico’s remaining system resources send the video signal from the emulated Mac out over VGA, meaning that monitors from the late 80s and on can be used with ease. There’s an option for micro SD card storage as well, allowing the retro Mac to have an incredible amount of storage compared to the original.
The emulation of the 80s-era Mac is available on a separate GitHub page for anyone wanting to take a look at that. A VGA monitor is not strictly required, but we do feel that displaying retro computer graphics on 4K OLEDs leaves a little something out of the experience of older machines like this, even if they are emulated. Although this Macintosh replica with a modern e-ink display does an excellent job of recreating the original monochrome displays of early Macs as well.
A thermal camera is a very handy tool to have, and [Learn Electronics Repair] wanted to try out the Thermal Master P2 for electronic repair, especially since it claims to have a 15 X digital zoom and 1.5 degree accuracy. The package proudly states the device is the “World 2nd Smallest Thermal Camera” — when only the second best will do.
The camera is tiny and connects to a PC or directly to a tablet or phone via USB C. However, it did look easier to use on the end of a cable for probing things like a PC motherboard. The focus was fairly long, so you couldn’t get extremely close to components with the camera. The zoom somewhat makes up for that, but of course, as you might expect, zooming in doesn’t give you any additional resolution.
He also compares the output with that of a multimeter he uses that includes an IR camera (added to our holiday gift list). That multimeter/camera combo focuses quite closely, which is handy when picking out a specific component. It also has a macro lens, which can zoom up even more.
We’ve looked at — or, more accurately, through — IR cameras in the past. If you are on a tight budget and you have a 3D printer, you might try this method for thermal imaging, but it doesn’t use the printer the way you probably think.
[Matthias] bought cheap clip leads online and, wisely, decided to check them. We’ve had the same experience that he’s had. Sometimes, these cheap leads are crimped and don’t make good contact. However, you can usually solder them and completely fix them. Not this time, however, as you can see in the video below.
The resistance for the leads was a bit on the high side, which is usually a sure sign of this problem. But soldering didn’t really make a big difference. A homemade clip lead, for example, read under 20 milliohms, but a test lead from the new batch read about 260 milliohms even after being soldered.
We have seen a recent surge of interest in whether it’s possible to grow potatoes and other plants in Martian soil, but what is the likelihood that a future (manned) lunar base could do something similar? To that end [Space Lab] is developing the LEAF project that will be part of NASA’s upcoming Artemis III lunar mission. This mission would be the first to have Americans return to the Moon by about 2028, using the somewhat convoluted multi-system SLS-Starship-Lunar Gateway trifecta. The LEAF (Lunar Effects on Agricultural Flora) science module will feature three types of plants (rape (Brassica Rapa), duckweed and cress (Arabidopsis thaliana) ) in an isolated atmosphere.
The main goal of this project is to find out how the plants are affected by the lunar gravity, radiation and light levels at the landing site at the south pole. This would be the equivalent of a hydroponics setup in a lunar base. After about a week of lunar surface time the growth chamber will be split up into two: one returning back to Earth for examination and the other remains on the surface to observe their long-term health until they perish from cold or other causes.
This is not the first time that growing plants on the lunar surface has been attempted, with China’s Chang’e 4 mission from 2019. The lander’s Lunar Micro Ecosystem featured a range of seeds as well, which reportedly successfully sprouted, but the project was terminated after 9 days instead of the planned 100 due to issues with heating the biosphere during the brutal -52°C lunar night. Hopefully LEAF can avoid this kind of scenario when it eventually is deployed on the Moon.
