2026-03-31 04:00:05
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.
With a simple visual design, the device could certainly fit into the same market we see so many other standalone cameras. Pictures from the camera look great without or with the included filter options if you want a more retro look. While currently there do appear to be some speed improvements needed, the best part of open source is that you yourself can help out!
We always love ambitious open source projects that look to build a true base for others to work on, and this seems like no exception! If you want similarly impressive feats of optical trickery, look no further than using scotch tape as a camera lens!
2026-03-31 02:00:36
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!
2026-03-31 01:00:54
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.
A UNESCO World Heritage Site since 1984, the Alhambra saw its first construction in 1238 CE by Muhammad I, the first Nasrid emir. The Nasrid dynasty would last from 1238 to 1491 CE when the Muslim state of al-Andalus fell during the Christian Reconquista.
Even after the end of the Nasrid dynasty would the Alhambra see further construction by Charles V in the 16th century. This made the Alhambra a rather unique amalgamation of Islamic and Renaissance-era architecture and engineering. Sadly by the 18th century the structure had been abandoned for centuries, invaded by squatters, and partially destroyed by the troops of Napoleon in 1812.
Only after these troubled times did an appreciation for such cultural heritage begin to flourish, with European and American tourists alike frequenting the area. One of them – US author Washington Irving – was so inspired by his visit in 1828 that he’d end up writing Tales of the Alhambra, containing many myths, stories, sketches, and essays pertaining to the site. This book in particular was instrumental in making an international audience aware of this site and its legacy.
This renewed attention resulted in the site becoming recognized first as a Spanish Cultural Heritage monument in 1870 and subsequently by UNESCO more than a century later.
Most fortresses of the era relied primarily on water cisterns that collected rainwater, as well as access to local rivers in some form, usually requiring human or animal labor to transport the latter. This was also how the Alhambra started in its initial fortress form, called the Alcazaba, meaning ‘citadel’ in Spanish, from Arabic al-qaṣabah. The water from this cistern didn’t just supply drinking water, but also for the bathhouse (hammam) and water elements like a pool or fountain for houses in the interior urban area. These houses additionally featured latrines that were flushed using this cistern water.
As the Alhambra expanded, with many palaces and related structures added, its water requirements increased correspondingly. Rather than some small decorative water features for a dozen houses and a communal bath, there were now reflective pools, fountains and a much larger population. This necessitated finding more efficient ways to get more water up the hill on which the Alhambra was constructed.
In addition to the aforementioned pump, there was also an aqueduct (the Acequia Real) that carried water from the Darro River. At a distance of 6.1 km from the fortress the river is at a sufficiently high elevation to provide water using just gravity. This aqueduct additionally provided water via additional branches to gardens and settlements beyond the Alhambra’s walls.
Many details can be found in this 2019 summary of applied hydraulic techniques at al-Andalus fortresses by Luis José García-Pulido and Sara Peñalver Martín.
As noted in that overview article, the reason for the Alhambra being significantly more advanced than other fortresses in the al-Andalus region was that it was the seat of the Nasrid dynasty, ergo it was only natural that it’d not only get all the palaces and comforts, but also the most advanced technologies for supplying water.
Unfortunately the unique pumping device that was used to supply the Alcazaba with water from the aqueduct was replaced in the 18th century with a more basic syphon system and the original device was removed. Up till that point the previous device had continued to work, despite the new owners of the Alhambra not understanding its operating principles. This left 19th century researchers like Cáceres to essentially fully rely on notes made during the previous century.
That said, there are also hints that the Alcazaba of the Antequera fortress used a similar device to pump water uphill, featuring ceramic pipes and other features that are described in by Sancho de Toledo in 1545. Unfortunately these accounts were all written by people who lacked the engineering know-how of the original Nasrid engineers – or any engineering knowledge at all – and thus had no understanding of the workings of these pumps.
This means that we will unfortunately never know exactly what this device looked like or how it worked, but we can still look at some mechanisms which we are familiar with today that could have been used. The concept of the hydraulic ram or pulser pump would seem to come closest compared to what little we do know.
Unlike a water pump that uses e.g. an impeller to impart kinetic energy and thus move the liquid, a self-powered pump uses physical phenomena like the water hammer effect or the fact that gas in a liquid will rise in order to effect a pumping effect. The hydraulic ram, for example, uses the water hammer effect and relies only on the kinetic energy of the incoming water.
The basic hydraulic ram functional sequence involves the water current pushing the normally open waste valve close, at which point the water hammer effect from the sudden current cessation forces the delivery valve open and pushing water into the delivery pipe.
This process will reverse again after a short while, sending a pressure wave upstream and eventually leading to the waste valve reopening. The downstream flow will then resume again, restarting the whole process.
In terms of technological complexity this is a very straightforward design, with the most complex parts being the valves and the pressure vessel that cushions the system against pressure shocks. This is however a design that would have been technologically quite feasible to manufacture and operate.
Another, similar type of pump is the gas lift pump. A very small variant of this is commonly used in devices like coffee percolators, with the pulser pump being in effect a very large implementation of the same general principle. Rather than applying heat to the water reservoir in order to create gas (i.e. steam), the pulser pump uses an air compressing effect that’s also used with water-powered trompe air compressors.
As water falls down a pipe it drags air bubbles along with it, which eventually arrive at the bottom where said air is trapped in a cavity while the water flows on to a lower elevation.
The thinner pipe through which water ultimately is pumped is inserted into this air chamber in such a way that it’ll alternately ingest water and air as the level of the latter varies over time. This way pockets of water become trapped between pockets of air, with a resulting pulsing output of water at the end of this pipe.
Whether the original device at the Alhambra or Antequera exactly matches either pump design will likely remain forever a mystery, but neither were beyond the technological means of the time, with the pulser pump arguably even more straightforward due to a lack of need for any valves and pressure vessels.
Although the Practical Engineering video focuses on this pump design, its author – Grady – was inspired by a Primal Space video that’s basically just history slop content, not citing any proper sources and propagating myths and misinformation as fact. The worst offender is probably the myth that the fountain that is found in the Court of the Lions was time-activated, with the only evidence for it being a clock being that there are twelve lion statues and there are two times twelve hours in a day.
When we consider the archaeological evidence that exists so far, as well as the findings during the recent restorations, it seems clear that the marble block with its many holes through which the water entered the bowl was intended to diffuse the flow. Around the bowl we can see a corresponding poem of twelve verses by the vizier and poet Ibn Zamrak.
In verses 3 through 7 it specifically refers to “[..] which runs to that which is still, that we know not which of them is flowing”. This quite strongly suggests that the theme was similar to that of the many reflective pools that were so popular around the Alhambra and elsewhere. The idea of it being a time-controlled mechanism would thus seem to be a purely Western interpretation, barring some hitherto unknown evidence appearing.
Perhaps the most cruel aspect of history is that, much like time itself, it has no concern for those of us who live in the present. Throughout the eons as empires rise and crumble back into dust, wondrous inventions are made and soon again forgotten, leaving behind only echoes of deeds and wonder.
If we’re lucky some of it is recorded in a form as durable as Sumerian clay tablets buried underneath desert sands, but if not then what once was shall never be again. This impermanence is the eternal curse of the past, and also the reason why it’s always so important to make multiple copies of your important data.
Due to the passage of time history is mostly just ruins, pot shards and bones buried in mud and sand. Some will try to spruce things up with one’s imagination resulting in faux romanticism, but this naturally bears little connection to the past. That today the Alhambra has been largely restored is testament to how much more respectful we now approach the past, but the parts that were erased after the demise of the Nasrid dynasty are sadly likely to be lost forever.
Featured image: Reflective pool of the Court of the Myrtles, looking north towards the Comares Tower. (Credit: Tuxyso, Wikimedia)
2026-03-30 23:30:15
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.
2026-03-30 22:00:27
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.
While this could, in theory, be from (and to) anywhere, direction finding has traced the signal to a US base near Stuttgart, Germany. In addition to using Farsi, Iran has repeatedly attempted to jam the signal, causing V32 to change frequencies a few times. There’s also a more recent, so far unidentified, jammer trying to block the signal.
In addition to direction finding, there is a surprising amount of information you can glean from the audio. The first few days of broadcasts had specific beeps in the background, which appear to be warning tones from a specific type of American military transmitter that warns the operator when encryption is not engaged. At first, a human read the numbers. Eventually, the station switched to using automated numbers.
In addition, there have been a few times when Windows 10 system sounds have leaked into the transmission. Other oddities are several cases where a word was read out in the middle of the numbers. We aren’t cryptographers, but that suggests the numbers refer to words in some sort of codebook, and that book doesn’t contain the proper words.
If you want to try your hand at decoding, you can hear the station on USB just under 8 MHz, or just listen to the recordings made by others (like the ones below or this one). You might like to read what other people say about it, too.
We are fascinated by spy stations. Even when they aren’t really number stations.
2026-03-30 19:00:34
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.
