Author: Lewin Day

3194 Articles

DIY Solar Generator Inspired By James Webb Telescope

May 30, 2025 by 36 Comments

If you look at this solar generator from [Concept Crafted Creations], you might think it’s somehow familiar. That’s because the design was visually inspired by the James Webb Space Telescope, or JWST. Ultimately, though, it’s purpose is quite different—it’s designed to use mirrors to collect and harness solar energy. It’s not quite there yet, but it’s an interesting exploration of an eye-catching solar thermal generator.

To get that JWST look, the build has 18 mirrors assembled on a 3D printed frame to approximate the shape of a larger parabolic reflector. The mirrors focus all the sunlight such that it winds up heating water passing through an aluminum plate. Each mirror was custom made using laser cut acrylic and mirror film. Each mirror’s position and angle can be adjusted delicately with screws and a nifty sprung setup, which is a whole lot simpler than the mechanism used on the real thing. The whole assembly is on a mount that allows it to track the movement of the sun to gain the most sunlight possible. There’s a giant laser-cut wooden gear on the bottom that allows rotation on a big Lazy Susan bearing, as well as a servo-driven tilting mechanism, with an Arduino using light dependent resistors to optimally aim the device.

It’s a cool-looking set up, but how does it compare with photovoltaics? Not so well. The mirror array was able to deliver around 1 kilowatt of heat into the water passing through the system, heating it to a temperature of approximately 44 C after half an hour. The water was warmed, but not to the point of boiling, and there’s no turbines or anything else hooked up to actually take that heat and turn it into electricity yet. Even if there were, it’s unlikely the system would reach the efficiency of a similarly-sized solar panel array. In any case, so far, the job is half done. As explained in the build video, it could benefit from some better mirrors and some structural improvements to help it survive the elements before it’s ready to make any real juice.

Ultimately, if you need solar power fast, your best bet is to buy a photovoltaic array. Still, solar thermal is a concept that has never quite died out.

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Another Doom Port To The Atari ST

May 29, 2025 by 7 Comments

Last week, we examined a Doom port for the venerable Atari ST. As is so often the way with this thing, one netted another, and [Steve] wrote in to inform us about a different version under the name DOOM8088ST.

The port is so named because it’s based on Doom8088, which was originally written for DOS machines running Intel 8088 or 286 CPUs. Both ports are the work of [FrenkelS], and aims to bring the Doom experience into the far more resource constrained environment of the Atari ST. There is only very limited sound, no saving, and it only supports Doom 1 Episode 1. Still, it’s quite recognizable as Doom!

Doom8088ST is tunable to various levels of performance, depending on what you’re running it on. Low mode (30 x 128) is suitable for stock Atari ST machines running at 8 MHz. It’s described as having “excellent” framerate and is very playable. If you’ve got an upgraded ST or Mega STe, you can try Medium (60 x 128), which has greatly improved visuals but is a lot heavier to run.

Files are on Github for those interested to run or tinker with the code. Don’t forget to check out the other port we featured last week, either, in the form of STDOOM. Video after the break.

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You Can Make Your Own Ribbon Mic With A Gum Wrapper

May 29, 2025 by 13 Comments

There are lots of different types of microphone, with the ribbon microphone being one of the rarer ones. Commercial versions are often prized for their tone and frequency response. You can make your own too, as [Something Physical] demonstrates using a packet of chewing gum.

Yes, the ribbon in this microphone was literally gained from Airwaves Extreme gum. It’s got nothing to do with freshness or the special mintiness quotient of the material, though; just that it’s a conductive foil and it makes the YouTube video more interesting to watch.

The gum wrapper is first soaked in hot water and then acetone, such that the paper backing can be removed. The foil is then corrugated with a tube press with some baking paper used for protection during this delicate process. The “motor” of the ribbon microphone is then produced out of plexiglass, copper tape, and a pair of powerful magnets. The ribbon is then stretched between the magnets and clamped in place, acting as the part of the microphone that will actually vibrate in response to sound. As it vibrates in the magnetic field, a current is generated in response to the sound. From there, it’s just a matter of hooking up a custom-wound transformer to the wires leading to the “motor” and it’s ready to test. It works off the bat, but there is some noise. Adding shielding over the transformer and a proper enclosure helps to make the microphone more fit for purpose.

If you’ve ever wanted to experiment with microphone construction, it’s hard to go past the joy of building a simple ribbon mic. You can experiment at will with different sizes and materials, too; you needn’t just limit yourself to different brands of gum!

We’ve featured some other great mic builds over the years, too. Video after the break.

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Researchers Are Slowly Finding Ways To Stem The Tide Of PFAS Contamination

May 29, 2025 by 67 Comments

If you’ve been following environmental news over the past couple of decades, you’ve probably heard about PFAS – those pesky “forever chemicals” that seem to turn up everywhere from drinking water to polar bear blood. They’re bad for us, and we know it, but they’ve been leeching into the environment for decades, often as a result of military or industrial activity. What’s worse is that these contaminants just don’t seem to break down—they stick around in the environment causing harm on an ongoing basis.

Now, researchers are finally cracking the code on how to deal with these notoriously stubborn molecules. It won’t be easy, but there’s finally some hope in the fight against the bad stuff that doesn’t just wash away.
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Supercon 2024: Using An Oscilloscope To Peek Below The Noise Floor

May 28, 2025 by 7 Comments

When you’re hunting for a signal with your oscilloscope, the stronger it is, the better. If it’s weak, you might struggle to tease it out from other interference, or even from the noise floor itself. You might wish that you were looking for something more obvious rather than the electromagnetic equivalent of a needle in a haystack.

Finding hidden signals below the noise floor may be a challenge, but it needn’t be an insurmountable one. James Rowley and Mark Omo came to the 2024 Hackaday Superconference to tell us how to achieve this with the magic of lock-in amplifiers.

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The Commodore 64 Gets An HDMI Upgrade

May 25, 2025 by 38 Comments

The Commodore 64 may remain the best selling computer of all time, but it has one major flaw. It doesn’t have HDMI! That makes it a total pain to use with modern displays. Thankfully, [Side Projects Lab] has whipped up an HDMI output board to solve this concerning oversight from the original designers.

The project was inspired by work by [Copper Dragon], who whipped up a nifty RGB output board. This device worked by reading the inputs to the C64’s VIC II graphics chip, which it then used to recreate a pixel-perfect video frames to then produce a quality analog video output. [Side Projects Lab] figured the same interception technique would be useful for producing a quality HDMI output.

The result was the HD-64. It sits inside the C64 in place of the original RF modulator. It uses an interleaver socket to capture digital signals going to the VIC II. It then feeds these signals to an emulated VIC II running inside an FPGA, which creates the pixel-perfect screen representation and synthesizes the proper digital HDMI output. Meanwhile, the analog audio output from the SID chip is captured from the RF modulator’s original header, and sent out via the HDMI output as well. The default output is super-sharp, but the device can be configured to allow scanlines and anti-aliasing if that’s more to your tastes.

If you want to hook your C64 up to a modern screen, this is going to be one of the tidiest and sharpest ways to do it. We’ve seen similar hacks for other platforms before, too. Video after the break.

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Nerf Blaster Becomes Remote Control Turret

May 24, 2025 by 5 Comments

For most of us, turrets that aim and shoot at things are the sole domain of video games. However, they’re remarkably easy to build with modern technology, as [meub] demonstrates. Meet the SwarmTurret.

The build is based around an existing foam blaster, namely the Nerf Swarmfire. This blaster was chosen for being easy to integrate into the build, thanks to its motorized direct-plunger firing mechanism and electronic trigger. It also has the benefit of being far less noisy and quicker to fire than most flywheel blasters.

For this build, the Nerf blaster was slimmed down and fitted to a turret base built with hobby servos and 3D printed components. The blaster is also fitted with a webcam for remote viewing. A Raspberry Pi is running the show, serving up a video feed and allowing aiming commands to be sent via a Websockets-based interface. Thus, you can login via a web browser on your phone or laptop, and fire away at targets to your heart’s content.

We’ve featured some great turrets before, like this Portal-themed unit.

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