Robot Makes Literal Daisy Chains

September 24, 2026 by No comments

[Jude Robinson]’s robot Daisy has an unusual function: making a literal chain of daisies. The device is his student final project and demonstrates how a system can replace sensing with clever mechanical constraints. Instead of bringing tools to bear on each daisy, the daisies are brought to the tools in a repeatable, deterministic way.

Daisy is essentially two X-Y gantries with grippers facing one another. Between them is a conveyor upon which daisies are fed, plus a blade at the top with a threading post nearby. A gripper takes a daisy, feeds the stem through the hole in the previous one, then lifts the new addition up to a scalpel blade which cuts a short incision. The thin threading post goes through the new hole in the new stem, ready for the next daisy to be inserted. The two gantries alternate roles, building the chain one daisy link at a time.

[Jude] says that daisy stem shape and diameter have the most impact on reliability, so it’s very important to constrain the daisies such that the scalpel and threading operations work reliably. This is primarily done with v-shaped profiles in the grippers which automatically center stems of different sizes. The sheath around the scalpel blade also plays a role in constraining and supporting the stems as they are gently pierced and sliced. Tuning these elements was a big part of making the system work.

Watch it in action in the video (embedded below) which shows how clever mechanical design can turn an uncertain problem — like how to handle daisies of different sizes — into a deterministic one with the help of clever mechanical design. That same concept is at work in everything from simple nut sorters to highly complex paper airplane machines.

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A 7-Segment Clock Built With No Digital Electronics

September 24, 2026 by 7 Comments

If you wanted to build a clock with a 7-segment display, there are a wide variety of ways you might go about it. You could grab some 74-series logic chips and create a whole bunch of counters and decoders to drive the display, or you could wire up a microcontroller with an RTC and have it do the hard work. Or, as a Japanese company once did… you could create a “digital” looking clock with no digital electronics whatsoever.

The geared mechanism and switch contacts are visible; they switch the neons of the various segments on and off at the correct times. Credit: YouTube video

[Mark Furneaux] set about tearing down a Lumitime clock, built by the Japanese company Tamura. From the outside, it appears to be a rather stylish digital clock, with a bold red 7-segment display lit with neons. And in some regards, it is. Only, the secret of this clock is that it doesn’t use digital electronics to do the job. There are no counters inside, no real-time clock module, no transistor-based logic chips doing the counting with the output of a 32.768 KHz crystal. Instead, a motor drives a series of gears that turn metal plates that move under sliding finger contacts. The gear train and the metal plates are designed such that the contacts turn the various segment neons on in the correct sequence to display the current time. It’s like a player piano, only instead of playing a tune, it’s switching the segments of a display on and off to display the right numerals at the right time.

It’s a neat way to do a “digital” clock from an era when proper digital electronics were still very expensive. We’ve seen all kinds of whacky 7-segment clocks before, too, like this amusing water-based build. Video after the break.

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Handheld Scanner Is A Radio Multi-tool

September 24, 2026 by No comments

These days, it’s possible to cram a whole lot of radio functionality into a very compact device. A great example of that is the LakeShark scanner from [SAMS0N1TE].

The LakeShark is based on the LilyGO T-Display P4—which combines an ESP32-P4 microcontroller with a 4.1 inch AMOLED touchscreen display. It comes with an onboard SX1262 LoRa radio module as well as GPS and a nine-axis Inertial Measurement Unit to boot. [SAMS0N1TE] then set it up to also hook up to an RTL-SDR Blog V3 or V4, providing all kinds of extra software-defined radio functionality.

It can scan everything from P25 Phase 1 trunking transmissions, to ADS-B, POCSAG, and even good old FM broadcast radio. If you want to listen in on what’s on the air, or see a minimap with tracks of the planes flying overhead, you can do it all with this rig. You can even investigate various bands with waterfall displays or try and look for activity from nearby nRF24 devices.

Ultimately, it’s a bit of a Swiss Army knife for radio fun—able to do all kinds of neat things, and it fits right in your pocket. We’ve featured some other great SDR hacks recently, too, like this $50 build with an impressive 20 MHz of bandwidth. If you’re cooking up your own gear for the ham shack and beyond, let us know on the tipsline.

UDP Broadcasting And The Brave New World Of IPv6

September 24, 2026 by 6 Comments

After recently working our way through UDP broadcasting and network subnetting all in the comfort zone of IPv4, it’s time to address the elephant in the room, the one wearing a bright neon ‘IPv6’ sign. Although it’s still very much a rumor at this point, supposedly IPv6 is slated to replace the venerable IPv4 protocol. Rather than just being IPv4-but-with-more-addresses, its designers took the opportunity to basically completely redesign the protocol for the futuristic world of the late 90s and the early 2000s.

Joking aside, IPv6 having been introduced in 1995 and still struggling to meaningfully displace IPv4 does invite some worries about just how easy it is to switch between these two fundamental internet protocols. Say if we wanted to join the future of the 2000s and adapt our software to speak IPv6 instead of IPv4, what would change about the aforementioned aspects of IPv4 UDP broadcasting and IPv4 subnetting?

Speaking as an ignorant developer who mostly knows IPv6 from those weird and hard to remember network addresses, as well as many broken router implementations, I’m not entirely convinced that I’m going to like what I’ll see.

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Standalone DJ System Runs On ESP32

September 24, 2026 by 8 Comments

There are plenty of ways to DJ with a laptop and various controller setups. However, if you find hauling around an entire computer can be a bit much, you might like this lighter system from [Daniel Vučinović].

It’s called Pajoniiir, and it’s intended to replace a laptop in the DJ booth. In its place stands an ESP32-P4 microcontroller, hooked up to a 4.3-inch touchscreen display in an off-the-shelf combo from Guition. The ESP32’s twin USB interfaces are hooked up in turn to a Pioneer DDJ-FLX4 controller, and a USB stick carrying a Rekordbox music library. The microcontroller is then also hooked up to a PCM5102A DAC module for audio output.

The ESP32 reads and plays tracks in MP3, WAV, and FLAC formats, responds to commands from the DJ controller, and displays the waveforms and other controls on the touchscreen. It’s doing most of what a laptop would do in this case, only it costs $50 and won’t get stuck in a bootloop for a Windows update 10 minutes before you’re due to go on.

We’ve featured a few good DJ controller hacks over the years, like this Hercules rig that was modded for better scratching.

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After Decades, NASA May Finally Replace Mars Relays

September 24, 2026 by 4 Comments

We’ve yet to find any definitive evidence that there’s biological life on present-day Mars, but to say it’s a dead planet isn’t exactly accurate. Since the first Viking lander touched down in 1976, a revolving cast of humanity’s robotic envoys have worked on and around the Red Planet — and as access to space becomes cheaper and more routine, the mechatronic population of Mars will continue to grow.

Given the number of landers, rovers, and orbiting spacecraft that have been sent to study Mars over the last 50 years, you might be surprised to find that the communications systems in place to transmit all that critical scientific data back to Earth aren’t nearly as robust as you’d think. While it’s understandable that the first craft to arrive at Mars had to operate in isolation, even the flagship Perseverance and Curiosity rovers carry their own high-gain radio systems so they can communicate directly with Earth. Given the incredible premium put on the mass of an interplanetary craft, each mission that needs to bring along its own link back to Earth effectively reduces its payload of much scientific equipment.

It’s not that satellites in orbit around the planet aren’t used to relay signals between Martian ground assets and their controllers back on Earth. In fact these relay links are used extensively for bandwidth-intensive tasks such as image transfers. But it’s also true that the craft currently available to act as intermediaries between the two planets aren’t terribly well suited to the task. The current fleet of Mars orbiters were conceived primary as research vehicles, and so every decision regarding their design and positioning around the planet was made with that goal in mind. What relatively limited capability they do have as communication relays is further hindered by the age of their hardware.

But after decades of false starts and shifting budgets, NASA is closer than ever to finally establishing the Mars Telecommunications Network, a dedicated high-bandwidth communication relay that will ensure current and future missions always have a way to phone home.

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Solar Powered Traffic Monitoring

September 24, 2026 by 4 Comments

[Marios Christoforou] recently undertook a Computer Engineering degree at the University of Cyprus. His final year project involved implementing a solar-powered device to count vehicular traffic, while logging results to the cloud.

The project is built around a Raspberry Pi 5, specifically the version with 4 GB of RAM. It runs Raspberry Pi OS and is equipped with a basic webcam with 720p video output. The single-board computer runs off a 12 volt lead acid battery, which is charged via a 100 W solar panel hooked up to a basic charger module. Identifying vehicles in traffic is achieved with the YOLOv8 Nano machine vision model, which outputs bounding boxes around cars, trucks, buses, and motorcycles captured in the webcam feed. Software algorithms are used to ensure vehicles are only counted once as they pass through the camera’s field of view.

There’s plenty of detail on how the project was refined to meet initial goals. To make the most of the solar power available, [Marios] optimized the setup with an eye to performance and low power draw. To that end, the Raspberry Pi had Bluetooth, the PCIe slot, audio, and HDMI ports all disabled, while the CPU and GPU were both under-clocked for good measure. Software tweaks were also used, like running headless and dropping unimportant parts of the video frame for more efficiency.

We’ve featured other homebrew traffic monitors before. These days, though, it’s Flock cameras that seem to be making all the headlines in this area.