A Tiny Reflecting Telescope For Portable Astronomy

For most of us who are not astronomers, the image that comes to mind when describing a reflecting telescope is of a huge instrument in its own domed-roof building on a mountain top. But a reflecting telescope doesn’t have to be large at all, as shown by the small-but-uncompromising design from [Lucas Sifoni].

Using an off-the-shelf mirror kit with a 76mm diameter and a 300mm focal length, he’s made a pair of 3D-printed frames that are joined by carbon fibre rods. The eyepiece and mirror assembly sit in the front 3D-printed frame, and the eyepiece is threaded so the telescope can be focused. There’s a 3D-printed azimuth-elevation mount, and once assembled, the whole thing is extremely compact.

While a common refracting telescope uses a lens and an eyepiece to magnify your view, a reflector uses a parabolic mirror to focus an image on a smaller diagonal mirror, and that mirror sends the image through the eyepiece. Most larger telescopes use this technique or a variation on it because large first-surface mirrors are easier to make than large lenses. There are also compound telescope types that use different combinations of mirrors and lenses. Which one is “best” depends on what you want to optimize, but reflectors are well known for being fairly simple to build and for having good light-gathering properties.

If you’d like to build your own version of this telescope then the files can all be found on Printables, meanwhile this isn’t the first 3D-printed telescope you might have seen on these pages. If you want to make your own mirror, that’s a classic hacker project, too.

hackaday.com/2025/12/20/a-tiny…

Building a Multi-Channel Pipette for Parallel Experimentation

One major reason for the high cost of developing new drugs and other chemicals is the sheer number of experiments involved; designing a single new drug can require synthesizing and testing hundreds or thousands of chemicals, and a promising compound will go through many stages of testing. At this scale, simply performing sequential experiments is wasteful, and it’s better to run tens or hundreds of experiments in parallel. A multi-channel pipette makes this significantly simpler by collecting and dispensing liquid into many vessels at once, but they’re, unfortunately, expensive. [Triggy], however, wanted to run his own experiments, so he built his own 96-channel multi-pipette for a fiftieth of the professional price.

The dispensing mechanism is built around an eight-by-twelve grid of syringes, which are held in place by one plate and have their plungers mounted to another plate, which is actuated by four stepper motors. The whole syringe mechanism needed to move vertically to let a multi-well plate be placed under the tips, so the lower plate is mounted to a set of parallel levers and gears. When [Triggy] manually lifts the lever, it raises the syringes and lets him insert or remove the multi-well. An aluminium extrusion frame encloses the entire mechanism, and some heat-shrink tubing lets pipette tips fit on the syringes.

[Triggy] had no particularly good way to test the multi-pipette’s accuracy, but the tests he could run indicated no problems. As a demonstration, he 3D-printed two plates with parallel channels, then filled the channels with different concentrations of watercolors. When the multi-pipette picked up water from each channel plate and combined them in the multi-well, it produced a smooth color gradient between the different wells. Similarly, the multi-pipette could let someone test 96 small variations on a single experiment at once. [Triggy]’s final cost was about $300, compared to $18,000 for a professional machine, though it’s worth considering the other reason medical development is expensive: precision and certifications. This machine was designed for home experiments and would require extensive testing before relying on it for anything critical.

We’ve previously looked at the kind of miniaturization that made large-scale biology possible and some of the robots that automate that kind of lab work. Some are even homemade.

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Thanks to [Mark McClure] for the tip!

hackaday.com/2025/12/20/buildi…

Hardware Store Marauder’s Map is Clarkian Magic

The “Marauder’s Map” is a magical artifact from the Harry Potter franchise. That sort of magic isn’t real, but as Arthur C. Clarke famously pointed out, it doesn’t need to be — we have technology, and we can make our own magic now. Or, rather, [Dave] on the YouTube Channel Dave’s Armoury can make it.

[Dave]’s hardware store might be in a rough neighborhood, since it has 50 cameras’ worth of CCTV coverage. In this case, the stockman’s loss is the hacker’s gain, as [Dave] has talked his way into accessing all of those various camera feeds and is using machine vision to track every single human in the store.

Of course, locating individuals in a video feed is easy — to locate them in space from that feed, one first needs an accurate map. To do that, [Dave] first 3D scans the entire store with a rover. The scan is in full 3D, and it’s no small amount of data. On the rover, a Jetson AGX is required to handle it; on the bench, a beefy HP Z8 Fury workstation crunches the point cloud into a map. Luckily it came with 500 GB of RAM, since just opening the mesh file generated from that point cloud needs 126 GB. That is processed into a simple 2D floor plan. While the workflow is impressive, we can’t help but wonder if there was an easier way. (Maybe a tape measure?)

Once an accurate map has been generated, it turns out NVIDIA already has a turnkey solution for mapping video feeds to a 2D spatial map. When processing so much data — remember, there are 50 camera feeds in the store — it’s not ideal to be passing the image data from RAM to GPU and back again, but luckily NVIDIA’s “Deep Stream” pipeline will do object detection and tracking (including between different video streams) all on the GPU. There’s also pose estimation right in there for more accurate tracking of where a person is standing than just “inside this red box”. With 50 cameras, it’s all a bit much for one card, but luckily [Dave]’s workstation has two GPUs.

Once the coordinates are spat out of the neural networks, it’s relatively simple to put footprints on the map in true Harry Potter fashion. It really is magic, in the Clarkian sense, what you can do if you throw enough computing power at it.

Unfortunately for show-accuracy (or fortunately, if you prefer to avoid gross privacy violations), it doesn’t track every individual by name, but it does demonstrate the possibility with [Dave] and his robot. If you want a map of something… else… maybe check out this backyard project.

youtube.com/embed/dO32ImnsX-4?…

hackaday.com/2025/12/20/hardwa…

A comment about yesterday’s president 🇺🇦 #Zelensky visit in 🇵🇱 #Poland - the context was very sensitive but fortunately everything worked well. Why was it sensitive?

1. 🇵🇱 Nawrocki is in an awkward position where he must remain loyal to his right-wing electorate, but at the same time fulfill the duties president of Poland. It’s not a criticism, just a statement of fact that is usually true for any elected politician with one particular voter base.
2. Polish right-wing is a broad spectrum between people with moderate religious and conservative but generally pro-EU and pro-Ukrainian views (PiS), down to complete Putinist freaks. Most importantly, even anti-EU parties like “Konfederacja” are divided. Thanks to numerous splits, the 🇷🇺 freaks are now mostly concentrated in “Konfederacja Korony Polskiej”.
3. Polish “liberals” (KO) chose to appeal to the centrist and left-wing electorate primarily by vilifying the whole right-wing. Daily political activity in Poland is infantile bashing between KO ministers and Nawrocki on a level so miserably stupid that is only comparable to MAGA.
4. Mutual accusations of being “pro-Russian” because someone visited Moscow as a diplomat in 2009 are a daily occurrence. In reality, it was PiS government that took all the refugees and send the first heavy weapons (MiG-29, tanks) to Ukraine in the first days of 2022 when other countries reluctantly offered helmets. PiS had done many bad things, but this thing they’ve done right.
5. Because the narratives have to be 100% black-and-white and “liberals” took the Ukraine topic, Nawrocki clearly felt compelled to play the opposite side. That is, the right end of his spectrum, which I was concerned would mean appealing to freaks obsessively talking about Volhynia and nothing else.

If that would happen, if Nawrocki eventually took the tribal side and decided to “play hard” with Zelensky, that would be a total disaster. Once again it would demonstrate that Poland is unable to operate as a single country and is doomed to remain a chaotic and unpredictable tribal entity forever.

Fortunately, that did not happen. I’ve listened to the whole 🇵🇱 Nawrocki speech in the presence of Zelensky. Nawrocki said all the necessary things about joint strategic goals and unity, and didn’t say anything unnecessary. He did mention “difficult topics” like Volhynia exhumations but even that he mentioned in a non-confrontational context of ongoing cooperation, which is a fact. He talked about military cooperation too. And when he talked about Volhynia and “gratitude” because that’s important for his electorate.

🇺🇦 Zelensky’s talk was in the same tone, so I won’t go into details. Yes, we have common goals; yes, unity is critical; yes, there are difficult topics and we are jointly working on them; yes, we also cooperate on military topics and we will do more. ✅

They were talking business. No hugs, no kisses, but honest business talk, and that’s precisely what they needed. ✅

I was a bit concerned about the outcome of yesterday’s visit, but it all worked well. And it gave Polish PM Tusk later full right to say that the worst news from yesterday’s Presidents’ meeting came out to be for Russia. Tusk met with Zelensky too late at night after he came back from Brussels, bringing the news of 90b EUR “loan” for Ukraine.

Overall ✅✅✅ for both countries and Europe.

The ‘Hidden’ Microphone inside the Sipeed NanoKVM

Recently, [Jeff Geerling] dropped into the bad press feeding frenzy around Sipeed’s NanoKVM, most notably because of a ‘hidden’ microphone that should have no business on a remote KVM solution. The problem with that reporting is, as [Jeff] points out in the video below, that the NanoKVM – technically the NanoKVM-Cube – is merely a software solution that got put on an existing development board, the LicheeRV Nano, along with an HDMI-in board. The microphone exists on that board and didn’t get removed for the new project, and it is likely that much of the Linux image is also reused.

Of course, the security report that caused so much fuss was published back in February of 2025, and some of the issues pertaining to poor remote security have been addressed since then on the public GitHub repository. While these were valid concerns that should be addressed, the microphone should not be a concern, as it’d require someone to be logged into the device to even use it, at which point you probably have bigger problems.

Security considerations aside, having a microphone in place on a remote KVM solution could also be very useful, as dutifully pointed out in the comments by [bjoern.photography], who notes that being able to listen to beeps on boot could be very useful while troubleshooting a stricken system. We imagine the same is true for other system sounds, such as fan or cooling pump noises. Maybe all remote KVM solutions should have microphone arrays?

Of course, if you don’t like the NanoKVM, you could always roll your own.

Top image: the NanoKVM bundle from [Jeff]’s original review. (Credit: [Jeff Geerling])

youtube.com/embed/RSUqyyAs5TE?…

hackaday.com/2025/12/20/the-hi…

Two-Wheeled Arduino Robot Project for Beginners

Here’s a fun build from [RootSaid] that is suitable for people just getting started with microcontrollers and robotics — an Arduino-controlled two-wheeled robot.

The video assumes you already have one of the common robotics kits that includes the chassis, wheels, and motors, something like this. You’ll also need a microcontroller (in this case, an Arduino Nano), a L293D motor driver IC, a 9 V battery, and some jumper wires.

The video goes into detail about how the two wheels connected to one motor each can move the robot in various directions: forward, backward, left, and right. The motors can be made to spin either forward or backward, depending on the polarity of the power supply, using an H-bridge circuit.

The L293D motor driver IC powers and controls the motors connected to the wheels. The L293D takes its commands from the Arduino. The rest of the video is spent going over the software for controlling the wheels.

When you’re ready to go to the next level, you might enjoy this robot dog.

youtube.com/embed/sn_NWZkKO5g?…

hackaday.com/2025/12/20/two-wh…