2026-01-20 08:00:07
If you ever built a line following robot, you’ll be nostalgic about [Jeremy’s] light-seeking robot. It is a very simple build since there is no CPU and, therefore, also no software.
The trick, of course, is a pair of photo-sensitive resistors. A pair of motors turns the robot until one of the sensors detects light, then moves it forward.
This is a classic beginner project made even easier with a 3D printer and PCB to hold the components. You might consider using an adjustable resistor to let you tune the sensitivity more easily. In addition, we’ve found that black tubes around the light sensors in this sort of application give you a better directional reading, which can help.
The robot only has two wheels, but a third skid holds the thing up. A freely-rotating wheel might work better, but for a simple demonstration like this, the skid plate is perfectly fine.
This is a good reminder that not every project has to be fantastically complex or require an RTOS and high-speed multi-core CPUs. You can do a lot with just a handful of simple components.
If you want to follow a line, the basic idea is usually the same, with perhaps some different sensors. Usually, but not always.
2026-01-20 05:00:46
How do you go about making a mirror with 128 segments, each of which can be independently angled? That was the question that a certain bloke over at [Time Sink Studio] found himself pondering on, to ultimately settle on a whole batch of mini-actuators bought through AliExpress. These stepper-based actuators appear to be akin to those used with certain Oppo smartphones with pop-up camera, costing less than half a dollar for a very compact and quite fast actuator.
The basic design is very much akin to a macro version of a micromirror device, as used in e.g. DLP projectors, which rely on a kinetic mirror mount to enable precise alignment. With the small actuators travelling up to 8 mm each, the mirrors can cover 73 mm at a distance of 4 meters from a wall.
With the required angle of the mirror being effectively just the application of the Pythagorean theorem, the biggest challenge was probably calibrating these linear motors. Since they’re open loop devices, they are zeroed much like the steppers on 3D printers, by finding the end limit and counting steps from that known point. This doesn’t make drift impossible, but for projecting light onto walls it’s clearly more than good enough.
2026-01-20 03:30:00
Syringes are pretty ergonomic, but when manually dispensing flux and solder paste it doesn’t take long before one wants a better way. [Elektroarzt]’s flux and solder paste dispenser design uses 3D-printed parts and minimal hardware (mostly M3x20 screws, and an optional spring) to improve handling and control.
How does it work? The ratcheting lever mechanism is similar to that of a hot glue gun, where an arm slips into notches in a rod when pressed down, driving it forward and never backward. In the process, a larger lever movement is translated into a shorter plunger travel, enhancing control.
The types of syringes this tool is meant to be used with have a plunger tip or piston (the rubber stopper-looking part, in contact with the liquid) inside the loaded syringe, but no plunger shaft attached to it. This is common with syringes meant to be loaded into tools or machines, and [Elektroarzt]’s tool can be used with any such syringe in a 10 cc size.
It’s an attractive design, and we like the way syringes top-load as well as the way the tool is made to lay flat on a tabletop, with the lever pointed up.
Want truly fine-grained control over your extrusions? Then check out this dispenser which really lets one dial in small amounts. You can also go motorized, and let a small PCB and stepper motor do the work.
2026-01-20 02:00:20
Get a handle on this bad boy! Okay, so those voids are really more for airing out your palms, I’d imagine, because palm sweat sure is real — you should see the pads of my Kinesis. This kind of looks like two sawed-off machine guns kissing, and I mean that in the best possible and non-violent way.
And yet, pricing (oh yeah, this is gonna be A Thing You Can Buy) will be around $115-155, depending upon whether you want the base kit, or the add-ons, too, minus switches and key caps.
So let’s get into the particulars here. As you can see, there are key wells and thumb clusters, inspired by other keyboards including your bog standard Maltrons, Kinesis Advantages and more modern, open-source takes like the Dactyl. [ntc490] loves the key well-thumb cluster combination, and I do, too (hello from the Glove80). And miraculously, the keys are hot-swappable via sockets.
Inside, you’d find direct wiring to the GPIOs, so I’m gonna guess that those are RP2040 clones in there. There’s no PCB, no diodes, no matrices to debug.
So please do go visit the thread if this keyboard appeals to you at this price point. I love it, but I would need more rows of keys, personally. The top reddit comment mentions this as well, and [ntc490] says that because the thing is modular, it can easily accommodate more keys in both the wells and the thumb clusters. I seriously want one of these. Just with a few more keys.
Remember [kleshwong]’s PSKEEB5 from a couple of Keebins ago, right before Christmas? He was going to open-source it if there was enough interest? Well, it seems that [kleshwong] decided to do it anyway and has since provided some new videos if you want to build one for yourself.
As a refresher, this thing has some really neat features like swing-out tenting feet, a pair of trackpoints, rotary encoders, and a carrying case that doubles as a laptop stand.
For the internals, any nice!nano-compatible boards will do. You’ll also need Kailh hot-swap sockets, among other things, naturally. If you have any trouble sourcing like the trackpoints for instance, you’re in luck, because [kleshwong] recently opened an online store. Go forth and build the ultimate portable split!
I’m using my MoErgo Glove80 pretty hardcore these days, driving them all crazy down at the library. But hey, it’s quieter than the big, echo-y Kinesis Advantage, even though they both have browns.
Once I saw the upcoming Go60 by MoErgo, though, I knew I simply needed wooden palm rests for the Glove80. So, over the course of two days, my father-in-law and I fabricated these fetching zebrawood rests, first from pink foam, then from poplar, and finally from book-matched zebra. I think we have a real conversation piece here.
Do you rock a sweet set of peripherals on a screamin’ desk pad? Send me a picture along with your handle and all the gory details, and you could be featured here!
I was sorry to hear that [Keenan Finucan] had to submit this twice in order to get my attention. But here we are, with what is probably the world’s first 3D-printed index typewriter. So, why is this filed under Historical Clackers? Because I said so, and because it’s based on a real antique index typewriter, the AEG Mignon Model 4. This first model of Mignon was designed between 1901-1903 by German company AEG. Mignons were produced until 1932.
I think this looks fabulous overall, and I rather like the way the index is laid out, which is decidedly non-alphabetical and, surprisingly, does not mirror the AEG index.
[Keenan] reports that thanks to months of work and revisions, this project is as accessible and repeatable as possible. You don’t even need any glue, and non-printed items are at a minimum. You will need a minimum XYZ build volume of 250 x 210 220 mm, TPU or other flexible filament, some springs, a bit of coat hanger wire, and a universal 1/2″ typewriter ribbon, which is pretty widely available.
Alright coders, designers, and engineers: this elegant hunk of metal is for you. What we’ve got here is Caligra’s c100 Developer Terminal. Described as a “computer for experts”, this is not meant for scrolling social media, although what developer can get through the day without a reddit break or three?
Let’s talk about that body. It’s entirely CNC-milled from a solid block of aluminium, which makes me think of the Icebreaker keyboard we saw here almost exactly a year ago. Both double as handy bludgeoning devices, but this one is decidedly more attractive. The bead-blasted finish of the c100 does simultaneously evoke modern and industrial design, so I’ll agree with Yanko on that note.
The coolest part is half-evident in the picture I chose. There’s a central magnetic pivot structure, and this lets you detach and fold the thing up even smaller, without any external hinges.
I thought the storage compartment gimmicky at first, but I’ve grown to like the idea of having a place for pens and whatnot. Yanko almost threatens to call it subversive in the face of what tech companies probably do not want you doing: opening the thing up. You are supposed to tinker with this one.
For some reason, the num pad is on the left, though I suppose this solves the distance-to-mouse problem. Yanko says the design uses Fitts’ law to accelerate task management, and this is supposed to explain why the keys are clustered the way they are. Basically, the placement of each key has been optimized for both speed an minimal hand movement. The wired mouse looks a bit uncomfortable, however.
This thing ships with Workbench OS, which is Linux-based and built specifically for technical work. There are no pop-ups in Workbench OS, which sounds amazing. So I would think that c100 is for writers, too, provided the keyboard clacks nicely.
Got a hot tip that has like, anything to do with keyboards? Help me out by sending in a link or two. Don’t want all the Hackaday scribes to see it? Feel free to email me directly.
2026-01-20 00:30:16
Although arguably redundant on a typical computer keyboard, the idea of embedding small screens into the buttons on devices like audio production gear that often have so many buttons can make a lot of sense. As exemplified by devices with a UX that regularly degrades into scrolling through options on a tiny screen. This was basically the impetus for [Craig J Bishop] a few years ago to set out on a design project called the SoundSlab audio sequencer/sampler/synthesizer and slab that would make those buttons much more functional.
Obviously, the right way to start the project is to bulk buy hundreds of 0.85″ 128×128 LCDs so that you’re firmly locked into that choice. Fortunately, it turned out that the most annoying part of this LCD was the non-standard 0.7 mm pitch on its flat flex cable (FFC). This was worked around with an PCB adapter milled out of some copper-clad FR-1, which gave it a convenient PMOD interface for straightforward hook-up to a Xilinx Artix-7 FPGA board.
The buttons themselves were designed as 3D printed key caps for the LCDs that clipped onto typical Cherry MX-style mechanical keys. This also revealed that the original FFCs were too short, so they had to be replaced with new FFCs, that also adapted it to a standard 0.5 mm pitch. With this a 4×4 button prototype board could be constructed for testing.
Since that prototype [Craig] has built a full-sized SoundSlab grid, with a custom FPGA board and HDMI input, of which a preview can be seen in the post, along with a promise by [Craig] to soon post the rest of the SoundSlab development.
Thanks to [JohnS_AZ] for the tip.
2026-01-19 23:00:21
The Internet has spoiled us. You assume network packets either show up pretty quickly or they are never going to show up. Even if you are using WiFi in a crowded sports stadium or LTE on the side of a deserted highway, you probably either have no connection or a fairly robust, although perhaps intermittent, network. But it hasn’t always been that way. Radio networks, especially, used to be very hit or miss and, in some cases, still are.
Perhaps the least reliable network today is one connecting things in deep space. That’s why NASA has a keen interest in Delay Tolerant Networking (DTN). Note that this is the name of a protocol, not just a wish for a certain quality in your network. DTN has been around a while, seen real use, and is available for you to use, too.
Think about it. On Earth, a long ping time might be 400 ms, and most of that is in equipment, not physical distance. Add a geostationary orbital relay, and you get 600 ms to 800 ms. The moon? The delay is 1.3 sec. Mars? Somewhere between 3 min and 22 min, depending on how far away it is at the moment. Voyager 1? Nearly a two-day round trip. That’s latency!
So how do you network at these scales? NASA’s answer is DTN. It assumes the network will not be present, and when it is, it will be intermittent and slow to respond.
This is a big change from TCP. TCP assumes that if packets don’t show up, they are lost and does special algorithms to account for the usual cause of lost TCP packets: congestion. That means, typically, they wait longer and longer to retry. But if your packets are not going through because the receiver is behind a planet, this isn’t the right approach.
DTN nodes operate like a mesh. If you hear something, you may have to act as a relay point even if the message isn’t for you. Unlike most store-and-forward networks, though, a DTN node may store a message for hours or even days. Unlike most Earthbound network nodes, a DTN node may be moving. In fact, all of them might be moving. So you can’t depend on any given node being able to hear another node, even if they have heard each other in the past.
Is this new? Hardly. Email is store-and-forward, even if it doesn’t seem much like it these days. UUCP and Fidonet had the same basic ideas. If you are a ham radio operator with packet (AX.25) experience, you may see some similarities there, too. But DTN forms a modern and robust network for general purposes and not just a way to send particular types of messages or files.
While the underlying transport layer might use small packets — think TCP — DTN uses bundles, which are large self-contained messages with a good bit of metadata attached. Bundles don’t care if they move over TCP, UDP, or some wacky RF protocol. The metadata explains where the data is going, how urgent it is, and at what point you can just give up and discard it. The bundle’s header has other data, too, such as the length and whether the current bundle is just a fragment of a larger bundle. There are also flags forbidding the fragmentation of a bundle.
DTN isn’t just a theory. It has been used on the International Space Station and is likely to show up in future missions aimed at the moon and beyond.
But even better, DTN implementations exist and are available for anyone to use. NASA’s reference implementation is ION (Interplanetary Overlay Network), and it is made for NASA-level safety. It will, though, run on a Raspberry Pi. You can see a training video about ION and DTN in the video below.
There are some more community-minded implementations like DTN2 and DTN7. If you want to experiment, we’d suggest starting with DTN7. The video below can help you get started.
We hear you. As much as you might like to, you aren’t sending anything to Mars this week. But DTN is useful anywhere you have unreliable crummy networking. Disaster recovery? Low-power tracking transmitters that die until the sun hits their solar cells? Weak signal links in hostile terrain. All of these use cases could benefit from DTN.
We are always surprised that we don’t see more DTN in regular applications. It isn’t magic, and it doesn’t make radios defy the laws of physics. What it does is prevent your network from suffering fatally from those laws when the going gets tough.
Sure. You can do this all on your own. No NASA pun intended, but it isn’t rocket science. For specialized cases, you might even be able to do better. After all, UUCP dates back to the late 1970s and shares many of the same features. Remember UUCP schedules that determined when one machine would call another? DTN has contact plans that serve a similar purpose, except that instead of waiting for low long-distance rates, the contact plan is probably waiting for a predicted acquisition of signal time.
But otherwise? You knew UUCP wasn’t immediate. Routing decisions were often due to expectations of the future. Indefinite storage was all part of the system. Usenet, of course, rode on top of UUCP. So you could think of Usenet as almost a planetary-scale DTN network with messages instead of bundles.
A Usenet post might take days to show up at a remote site. It might arrive out of order, or twice. DTN has all of these same features. So while some would say DTN is the way of the future, at least in deep space networking, we would submit that DTN is a rediscovery of some very old techniques when networking on Earth was as tenuous as today’s space networks.
We’re sure that by modern standards, UUCP had some security flaws. DTN can suffer from some security issues, too. A rogue node can accept bundles and silently kill them, for example. Or flood the network with garbage bundles.
Then again, TCP DoS or man-in-the-middle attacks are possible, too. You simply have to be careful and think through what you are doing, if it is possible someone will attack your network.
So next time your project needs a rough-and-tumble network that survives even when you aren’t connected to the gigabit LAN, maybe try DTN. It has come a long way, literally and figuratively, since 2008. Well, actually, since 1997, as you can see in the video below. Whatever you come up with, be sure to send us a tip.
