Retro Open Source Camera Straight From The ’90s

March 30, 2026 by No comments

In our modern society, we have started to take the humble camera for granted. Perhaps because of this, trendy standalone cameras have started to take off. Unfortunately, most of the time these cameras are expensive and not any better than those in our everyday smartphones. If only there were some open-source solution where you could build and customize your own standalone device? [Yutani] has done just that with the SATURNIX.

Simple microcontrollers and cameras meant for Raspberry Pis are a dime a dozen these days. Because of this, it’s no surprise to hear that the SATURNIX is based on recognizable hardware, a Raspberry Pi Zero 2W and an Arducam 16MP sensor. The Pi Zero powers both the sensors’ capture abilities and the interactive LCD display.

Continue reading “Retro Open Source Camera Straight From The ’90s” →

Recreating One Of The First Hackintoshes

March 30, 2026 by 1 Comment

Apple’s Intel era was a boon for many, especially for software developers who were able to bring their software to the platform much more easily than in the PowerPC era. Macs at the time were even able to run Windows fairly easily, which was unheard of. A niche benefit to few was that it made it much easier to build Hackintosh-style computers, which were built from hardware not explicitly sanctioned by Apple but could be tricked into running OSX nonetheless. Although the Hackintosh scene exploded during this era, it actually goes back much farther and [This Does Not Compute] has put together one of the earliest examples going all the way back to the 1980s.

The build began with a Macintosh SE which had the original motherboard swapped out for one with a CPU accelerator card installed. This left the original motherboard free, and rather than accumulate spare parts [This Does Not Compute] decided to use it to investigate the Hackintosh scene of the late 80s. There were a few publications put out at the time that documented how to get this done, so following those as guides he got to work. The only original Apple part needed for this era was a motherboard, which at the time could be found used for a bargain price. The rest of the parts could be made from PC components, which can also be found for lower prices than most Mac hardware. The cases at the time would be literally hacked together as well, but in the end a working Mac would come out of the process at a very reasonable cost.

[This Does Not Compute]’s case isn’t scrounged from 80s parts bins, though. He’s using a special beige filament to print a case with the appropriate color aesthetic for a computer of this era. There are also some modern parts that make this style computer a little easier to use in today’s world like a card that lets the Mac output a VGA signal, an SD card reader, and a much less clunky power supply than the original would have had. He’s using an original floppy disk drive though, so not everything needs to be modernized. But, with these classic Macintosh computers, modernization can go to whatever extreme suits your needs.

Thanks to [Stephen] for the tip!

Continue reading “Recreating One Of The First Hackintoshes” →

Reflective pool of the Court of the Myrtles, looking north towards the Comares Tower. (Credit: Tuxyso, Wikimedia)

Medieval Alhambra’s Pulser Pump And Other Aquatic Marvels

March 30, 2026 by 1 Comment

Recently the Practical Engineering YouTube channel featured a functional recreation of a pump design that is presumed by some to have been used to pump water up to the medieval Alhambra palace and its fortress, located in what is today Spain. This so-called pulser pump design is notable for not featuring any moving parts, but the water pump was just one of many fascinating engineering achievements that made the Alhambra a truly unique place before the ravages of time had their way with it.

Although the engineering works were said to still have been functional in the 18th century, this pumping system and many other elements that existed at the peak of its existence had already vanished by the 19th century for a number of reasons. During this century a Spanish engineering professor, Cáceres, tried to reconstruct the mechanism as best as he could based on the left-over descriptions, but sadly we’ll likely never know for certain that it is what existed there.

Similarly, the speculated time-based fountain in the Court of the Lions and other elements are now forever lost to time, but we have plenty of theories on how all of this worked in a pre-industrial era.

Continue reading “Medieval Alhambra’s Pulser Pump And Other Aquatic Marvels” →

Dotterboard smt counter

Tame The Tape: Open-Source Dotterboard For Bulk SMT Parts

March 30, 2026 by 4 Comments

One of the great things about building electronics today is how affordable SMT components have become — sometimes just fractions of a cent each. That low price often means ordering far more than you need so you’ll have spares on hand the next time a project calls for them. Keeping track of exactly how many of each part you actually have, though, is rarely easy. To solve that problem, [John] built the Dotterboard, an open-source SMT tape counter.

While working on some of his other projects, [John] found himself managing thousands of tiny SMT parts and decided it was time to automate the counting. The Dotterboard takes inspiration from the BeanCounter — a compact, portable SMT tape counter — but expands the design to handle larger components beyond the 8 mm tapes the BeanCounter targets.

The Dotterboard is mostly 3D-printed and uses just a few common hardware parts such as springs and ball bearings. An OLED displays the current count, which comes from an encoder tracking movement and multiplying by the number of components per hole. At the heart sits an RP2040 Zero that needs nothing more than a single USB-C cable for power, unlike the bulky industrial SMT counters that demand AC outlets and desk space.

Be sure to check out all the details of the build on [John]’s website, and grab the files from his GitHub if you want to make your own. Let us know what are some projects you’ve done to save you the headache of doing the same task by hand for hours on end.

Continue reading “Tame The Tape: Open-Source Dotterboard For Bulk SMT Parts” →

Spy Tech: Conflicts Bring A New Number Station

March 30, 2026 by 7 Comments

If you know much about radios and espionage, you’ve probably encountered number stations. These are mysterious stations that read out groups of numbers or otherwise encoded messages to… well… someone. Most of the time, we don’t know who is receiving the messages. You’d be excused for thinking that this is an old technology. After all, satellite phones, the Internet, and a plethora of options now exist to allow the home base to send spies secret instructions. However, the current-day global conflict has seen at least one new number station appear, apparently associated with the United States and, presumably, targeting some recipients in Iran, according to priyom.org.

As you might expect, these stations don’t identify themselves, but the Enigma Control List names this one as V32. It broadcasts two two-hour blocks a day at 0200 UTC and a repeat at 1800 UTC. Each message starts with the Farsi word for “attention” followed by what is assumed to be some header information as two 5-digit groups. Then there is a set of 181 five-digit groups. Each message is padded out to take 20 minutes, and there are six messages in each transmission.

Continue reading “Spy Tech: Conflicts Bring A New Number Station” →

An overlay is shown on a topographical map. High points are highlighted in blue. The letters "A" and "B" are shown in red text at two points.

Using A Scientific Satellite For Passive Radar

March 30, 2026 by 1 Comment

The basic principle of radar systems is simple enough: send a radio signal out, and measure the time it takes for a reflection to return. Given the abundant sources of RF signals – television signals, radio stations, cellular carriers, even Wi-Fi – that surround most of us, it’s not even necessary to transmit your own signal. This is the premise of passive radar, which uses passive RF illumination to form an image. The RF signal doesn’t even need to come from a terrestrial source, as [Jean Michel Friedt] demonstrated with a passive radar illuminated by the NISAR radar-imaging satellite (pre-print paper).

NISAR is a synthetic-aperture radar satellite jointly built by NASA and ISRO, and it completes a pass over the world every twelve days. It uses an L-band chirp radar signal, which can be picked up with GNSS antennas. One antenna points up towards the satellite, and has a ground plane blocking the signal from directly reaching the second antenna, which picks up reflections from the landscape under observation. Since the satellite would illuminate the scene for less than a minute, [Jean-Michel] had to predict the moment of peak intensity, and achieved an accuracy of about three seconds.

The signals themselves were recorded with an SDR and a Raspberry Pi. High-end, high-resolution SDRs such as the Ettus B210 gave the best results, but an inexpensive homebuilt MAX2771-based SDR also produced recognizable images. This setup won’t be providing any particularly detailed images, but it did accurately show the contours of the local geography – quite a good result for such a simple setup.

If you’re more interested in tracking aircraft than surveying landscapes, check out this ADS-B-synchronized passive radar system. Although passive radar doesn’t require a transmitter license, that doesn’t mean it’s free from legal issues, as the KrakenSDR team can testify.

The Hazards Of Charging USB-C Equipped Cells In-Situ

March 30, 2026 by 17 Comments

Can you charge those Li-ion based cells with USB-C charging ports without taking them out of the device? While this would seem to be answered with an unequivocal ‘yes’, recently [Colin] found out that this could easily have destroyed the device they were to be installed in.

After being tasked with finding a better way to keep the electronics of some exercise bikes powered than simply swapping the C cells all the time, [Colin] was led to consider using these Li-ion cells in such a manner. Fortunately, rather than just sticking the whole thing together and calling it a day, he decided to take some measurements to satisfy some burning safety questions.

As it turns out, at least the cells that he tested – with a twin USB-C connector on a single USB-A – have all the negative terminals and USB-C grounds connected. Since the cells are installed in a typical series configuration in the device, this would have made for an interesting outcome. Although you can of course use separate USB-C leads and chargers per cell, it’s still somewhat disconcerting to run it without any kind of electrical isolation.

In this regard the suggestion by some commentators to use NiMHs and trickle-charge these in-situ similar to those garden PV lights might be one of the least crazy solutions.

Continue reading “The Hazards Of Charging USB-C Equipped Cells In-Situ” →