The Many Leaning Towers Of Santos, Brazil

January 14, 2025 by 37 Comments

If you’ve ever gazed at the shoreline of Santos, Brazil, and felt like something was tugging at your inner eye level, you’re not alone. In fact, you’ve spotted one of the world’s most bizarre architectural phenomena.

Santos is an interesting contradiction—it’s a sunny coastal city with pristine beaches that also plays host to a bustling port. What draws the eye, however, is the skyline—it’s decidedly askew. This isn’t a Photoshop job or some avant-garde urban planning experiment, either. It’s a consequence of engineering hubris, poor planning, and geology just doing its thing.

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It’s A Doughnut, In Hardware

January 14, 2025 by 5 Comments

Making a physical doughnut is easy enough, given a good dough recipe and a nice hot deep fat fryer. But have you ever considered making a one in physical electronic hardware, on an ASIC? [A1k0n] has, at least in terms of making a virtual doughnut. It’s a hardware implementation of a ray tracer which renders a rotating doughnut to a VGA screen, and it comes courtesy of around 7000 logic cells on the latest iteration of Tiny Tapeout.

We will not pretend to be mathematical or ray tracing experts here at Hackaday so we won’t presume to explain in detail the circuitry, suffice to say that the clever hack here lies in a method using only shift and add operations rather than the complex trigonometry we might expect. It uses a slightly esoteric VGA mode to work with the device clock, so while CRT monitors have no problems it can have artifacts on an LCD. The full explanation goes into great detail, for the math heads among you.

We’ve reported on quite a few Tiny Tapeout projects over the years, as the many-ASICs-on-a-chip extends its capabilities.

New Frontiers For Nissan Leaf Motor And Battery

January 14, 2025 by 9 Comments

Nissan started off with a massive lead in the electric vehicle industry — their Leaf was the first mass-market EV available and the highest-selling EV until 2020. But the company has begun to lag behind other automotive manufacturers and their more diverse, modern offerings. As an example, the Leaf still doesn’t have active cooling for its battery packs. On the plus side, though, these cars are pretty easy to work on and parts for them are widely available. This includes the battery pack and motor, which can be dropped in to other non-EV Nissan products like this Nissan Frontier.

For conversions using the Leaf battery pack and motor, [Paul] points out that it’s important to find the motor with the inverter and power distribution unit all integrated together, rather than sourcing them all separately since they don’t always mix-and-match well. There are several third-party parts available for getting these motors running in other applications, including a coupler to mate the motor to a transmission. However, this still needs some custom fabrication to properly attach to the Frontier’s drivetrain. With a new controller as well, the Frontier engine can be pulled, the Leaf engine dropped in, and the battery set into the bed and connected.

A followup video shows [Paul] driving his new EV down a neighborhood street, but it looks like there are still a few things to polish up before it’s ready to hit the open highway including a more robust housing for the battery. But, if donor vehicles can be found like a truck body and Leaf drivetrain components, this type of modification can be done for a surprisingly small cost. These EV batteries can also be put to work as home power banks as well.

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Homebrew Retro Console Runs On PIC32

January 13, 2025 by 6 Comments

[Chad Burrow] decided to take on a noble task—building a “retro” style computer and video game console. Only, this one is built using somewhat modern hardware—relying on the grunt of the PIC32MZ2048EFH144 to get the job done. Meet the Acolyte Hand PIC’d 32.

It’s name might be a mouthful, but that chip can pull off some great feats! With a clock speed of 200 MHz, it’s not  short on processing power, though RAM and flash storage are somewhat limited at just 512 KB and 2MB respectively. [Chad] was able to leverage those constraints to get a VGA output working at a resolutions up to 800 x 600, with up to 65,000 colors—though 256 colors is more practical due to memory concerns. The Acolyte Hand also rocks two 8-bit audio channels. It has a pair of Genesis-compatible controller ports as well as PS/2 and USB for keyboards and mice, along with more modern Xbox 360 controllers.

[Chad] cooked up some software to put it through its paces, too. It’s got a Tetris clone on board, and can also run Game Boy games at full speed via the Peanut-GB emulator. That provides for a pretty rich game library, though [Chad] notes he plans to develop more native video games for his system to demo at his local college. Design files are on Github for the curious.

This project is a great example of just how powerful modern microcontrollers have become. Once upon a time, just driving a simple black-and-white graphical LCD might have taken some real effort, but today, there are pixels and clock cycles to spare in projects like these. Truly a wonderous world we live in!

Selectively Magnetizing An Anti-Ferromagnet With Terahertz Laser

January 13, 2025 by 7 Comments

It’s a well-known fact that anti-ferromagnetic materials are called that way because they cannot be magnetized, not even in the presence of a very strong external magnetic field. The randomized spin state is also linked with any vibrations (phonons) of the material, ensuring that there’s a very strong resistance to perturbations. Even so, it might be possible to at least briefly magnetize small areas through the use of THz-range lasers, as they disrupt the phonon-spin balance sufficiently to cause a number of atoms to ‘flip’, resulting in a localized magnetic structure.

The research by [Baatyr Ilyas] and colleagues was published in Nature, describing the way the 4.8 THz pulses managed to achieve this feat in FePS3 anti-ferromagnetic material. The change in spin was verified afterwards using differently polarized laser pulses, confirming that the local structures remained intact for at least 2.5 milliseconds, confirming the concept of using an external pulse to induce phonon excitation. Additional details can be found in the supplemental information PDF for the (sadly paywalled with no ArXiv version) paper.

As promising as this sounds, the FePS3 sample had to be cooled to 118K and kept in a vacuum chamber. The brief magnetization also doesn’t offer any immediate applications, but as a proof of concept it succinctly demonstrates the possibility of using anti-ferromagnetic materials for magnetic storage. Major benefit if such storage can be made more permanent is that it might be more stable and less susceptible to outside influences than traditional magnetic storage. Whether it can be brought out of the PoC stage into at least a viable prototype remains to be seen.

Fluid Simulation Pendant Teaches Lessons In Miniaturization

January 13, 2025 by 4 Comments

Some projects seem to take on a life of their own. You get an idea, design and prototype it, finally build the thing and — it’s good, but it’s not quite right. Back to the drawing board, version 2, still not perfect, lather, rinse, repeat. Pretty soon you look around to discover that you’ve built ten of them. Oops.

That seems to be the arc followed by [mitxela] with this very cool fluid simulation pendant. The idea is simple enough; create a piece of jewelry with a matrix of tiny LEDs that act like the pendant is full of liquid, sloshing about with the slightest movement. In practice, though, this project was filled with challenges. Surprisingly, [mitxela] doesn’t seem to number getting a fluid dynamics simulation running on a microcontroller among those problems, at least not to a great degree. Rather, the LED matrix seemed to cause the most problems, both in terms of laying it out on the 25-mm diameter PCB and how to address the LEDs with relatively limited GPIO on the STM32 microcontroller. The solution to both was diagonal charlieplexing, which reduces the number of vias needed for the 216-LED matrix and allows the 0402 to be densely packed, along with providing some tolerance for solder bridging.

And then there’s the metalworking heroics, which no [mitxela] project would be complete without. This seems to be where a lot of the revisions come from, as the gold-plated brass case kept not quite living up to expectations. The final version is a brass cup containing the LiR2450 rechargeable battery, a magnetic charging connector, and the main PCB, all sealed by a watch crystal. The fluid simulation is quite realistic and very responsive to the pendant’s position. The video below shows it in action along with a summary of the build.

If you want to catch up on [mitxela]’s back catalog of miniaturized builds, start with his amazing industrial ear adornments or these tiny matrix earrings. We’re also fond of his incredible shrinking MIDI builds. Continue reading “Fluid Simulation Pendant Teaches Lessons In Miniaturization” →

Electromechanical 7-Segment Display Is High Contrast Brilliance

January 13, 2025 by 8 Comments

The seven-segment display is most well known in LED form, but the concept isn’t tied to that format. You can build a seven-segment display out of moving parts, too. [tin-foil-hat] has achieved just that with a remarkably elegant design.

As you might expect, the build relies heavily on 3D-printed components—produced in white and black plastic to create a high-contrast display. It’s a simple choice that makes the display easy to read in a wide variety of lighting conditions, and far less fussy than toying with LEDs and diffusers and all that.

Actuation of each display segment is achieved electromagnetically. Effectively, each segment behaves like a flip dot, with the orientation controlled by energizing one of two electromagnets per segment. Controlling the electromagnets is an ESP32, which is hooked up to the various segments via a Darlington transistor array, with multiplexing used to minimize the number of IO pins required. A shift register was also employed to let the microcontroller easily drive four of these electromechanical digits.

It’s a simple build, well explained—and the final result is aesthetically pleasing. We’ve seen a few builds along these lines before, albeit using altogether different techniques. Lots of different techniques, in fact! Video after the break.

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