TechyMagThings

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.

[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.

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.

Even for the non-musical among us there is a lot of fun to be had with a simple synthesiser and sequencer, as the different controls can be manipulated to show their effect on the sound. Beeper, from [Valentyn Danylchuk] is just such a synth, and with only built-in loops, it has a focus on the instrument rather than the arrangement. What you get are a simple set of controls, from which you can modify the sound to your liking. We’ve been playing with it here, and it’s surprisingly addictive.

The target for Beeper is ESP32 microcontrollers, with builds for the S3 and P4, but there’s also a web version and one for the Mac. It’s operated using the arrow keys on your keyboard, and  the web one at least isn’t the most responsive piece of software. Below the break you can see (and hear) it on a Tanmatsu ESP32-P4 based handheld computer.

It’s certain that there are more accomplished synthesisers and sequencers to be found, but there’s still a place for one that’s simply a musical toy like this. Sometimes playing with something is more important than achieving something with it.

[Yeo Kheng Meng] has a problem: he likes Windows 98, but he also likes his 2020 ThinkPad, which only has an xHCI USB controller– you know, the kind needed for USB 3.0, something that post-dates Windows 98 by a full decade. Drivers? Finding none existed, he decided to do it himself, or at least guide the process of using  LLMs to produce drivers for Windows 98 and up.

Some of you just stopped reading, but can you blame him for making a demonic pact for this project? Driver development isn’t really a one-man show, especially as a part-time hobby project you’re not sure anyone else will ever use. If you do want to use it, you can find the code on GitHub.

It does work, though, he admits it might be buggy. Unlike purely vibe-coded projects, [Meng] intends to address bugs put forth in the repo, at least. If you want to know how he did it, check out the link to [Meng]’s blog– which is human-authored, we can tell– and the videos embedded therein. He demonstrates it working on a 2020 ThinkPad, which should be usable even with Windows 11, and another model from 2016– neither of which have any old-style USB ports. Older laptops might, while any desktop can just use a PCI card with a USB2.0 controller– or you can do like [Meng] did prior to this project, and use the PCI card via adapters. 

[Yeo Kheng Meng] evidently gets as much of a kick out of joining old and new as we do, like running DOS a modern ThinkPad X13, and running Slack on Windows 3.11 For Workgroups on a slightly-less-modern but still 21st Century Thinkpad T400.

Sometimes along comes a hack with a personal angle, and in a video showing Irish bog ore smelting, we find an appropriate follow up to a Hackaday expedition back in 2019. [Alec Steele] joined Irish Bloomery Iron, for a weekend with a medieval blast furnace.

Our brush with bog ore came in a trip to Hack42 in Arnhem, the Netherlands, where a team of Dutch hackers built a furnace from firebricks in an attempt to do the same thing. The Dutch attempt ended with a lot of mixed slag and very little iron, and looking at how the Irish furnace was constructed we see some clues to their success. Their air injection using a perforated sheet of clay and the air blast injected to form a venturi is particularly interesting,as is the shape of the furnace.

The iron bloom is lifted out through the top of the furnace rather than being tapped as molten iron, and we’re treated to it being worked into a usable bar of iron. Having spent a day with our Dutch friends doing the same work only to have scraps of iron, we’re mightily impressed with the results from the Irish smelters. You can visit their website at www.irishbloomeryiron.com.

Although [Arkandas] disclaims any interest in being a ‘car guy’, this is somewhat ironic in light of the sheer amount of modding he has performed on a range of cars over the years, a recent misadventure involving a BMW Mini F56’s infotainment system replacement and some light ECU reprogramming included. What happened exactly is covered in a detailed breakdown in a blog post.

One of the aspects that [Arkandas] disliked about this car was its iDrive infotainment system, itself a stripped-down version of the full-fat infotainment system in ‘real’ BMW cars, with a small screen and awkward UX. The idea was to replace this with a more full-featured modern system.

Since the infotainment system does hook into the car’s CAN buses and other systems it has to be compatible, of course. This took some research before ultimately a fancy €700 aftermarket replacement was ordered from a Chinese seller.

Long story short, the device was mostly compatible aside from a connector wired wrongly and creating a short. This was fixed, but then the loosely fitted display toppled off during a test drive and broke, so a replacement screen was ordered. This screen arrived without requisite factory programming, so [Arkandas] embarked on a long reverse-engineering session.

Before he was able to extract firmware from the broken display and flash it onto the new display he was offered a brand-new replacement for the whole device, which he accepted in return for sending the old unit back. Although this still left him with a range of questions, at least the new infotainment looks pretty spiffy.

The worst part about the whole experience was just how much waiting and agonizing over poor after-sale support was involved, along with all the things that can go wrong and turn a fun afternoon of fitting shiny new parts into a months-long ordeal. Since modern cars are basically just a stack of computers on wheels, this ensures that even ‘not car guys’ will be doing a lot more of such fun car modding.

A good rule of thumb is that everything that can interact with electromagnetic (EM) radiation is an antenna, which includes our mostly-salty-water-containing bodies and also raindrops and moisture in the air. This can be both a benefit or a curse, depending on whether you’re trying to broadcast a signal in rainy weather or operating a weather radar. Here it’s essential to understand what kind of antenna a raindrop really is to optimize for either scenario, which is where a video by [Marshall Bruner] provides a solid primer.

The video focuses on the Rayleigh regime, which may be familiar from atmospheric Rayleigh scattering that also affects EM radiation in the visible spectrum, giving those of us gifted with retinas capable of color vision those nice blue skies.

As the EM radiation passes through these little droplets in the air, their neutral alignment gets disrupted and causes them to turn into dipole antennae, moving along with the incoming frequency. The backscatter part of this event is what returns to the emitter, such as a weather radar. Here the volume and permittivity of the moisture sphere determines the strength of the signal, which is great if you’re actually operating a weather radar and wants to map out the moisture in some clouds, including the presence of snow.

There’s quite a lot of mathematics involved which is covered in the video and expanded upon in a related Python notebook.