Solar Powered Flower Chases The Light

September 2, 2023 by Lewin Day 2 Comments

Many plants are capable of tracking the sun in order to get the most possible light. [hannu_hell] built a solar powered sculpture that replicates this light sensitivity for the benefit of better charging its own batteries, allowing it to run theoretically indefinitely where suitable light was available.

The 3D-printed flower features six movable petals mounted on an articulated stem. The flower’s leaves themselves bear solar panels that collect energy, analogous to leaves on a plant. A Raspberry Pi Pico is at the heart of the show, which is outfitted with a DS1307 real-time clock and a ST7735 TFT display for displaying date and time information. It’s also responsible for controlling servos that aim the flower’s solar panels towards the brightest light source available. This is achieved by using the Pico to read several photoresistors to determine light levels and adjust the leaves accordingly.

It’s a fun build, and one that could teach useful lessons relevant to even large-scale solar arrays. Video after the break.

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Will An 8088 Run DOOM? Now, Yes It Will!

September 2, 2023 by Jenny List 12 Comments

The question on everyone’s lips when a new piece of hardware comes out is this: Will it run DOOM? Many pieces of modern hardware have been coaxed into playing id Software’s 1993 classic, but there have always been some older machines that just didn’t have the power to do it. One of them has now been conquered though, and it’s a doozy. [Frenkel]’s Doom8088, as its name suggests, is a port of the game for the original PC and AT.

As can be seen in this gameplay video, it’s not always the slickest of gaming experiences. But it works, so the question is, how on earth can a machine that was below the spec of the original, run this game? The answer comes in it being a port of GBADoom for the Game Boy Advance, a platform with less memory than a DOS PC. It still relies on extensive hard disk access for every frame though, which leaves it snail-like.

We set out to install it ourselves on one of the web based PC emulators, but fell over on the size of the required Watcom installation. If any of you have the real thing lying around though, we’d love to hear about how the game performed in the comments.

We’ve shown you so many ports of DOOM over the years to have lost count. One of our favourite recent ones uses an extremely unconventional but very retro display.

To Give Is Better Than To Receive

September 2, 2023 by Elliot Williams 24 Comments

Better to give a talk at a hacker event, that is. Or in your hackerspace, or even just to a bunch of fellow nerds whenever you can. When you give the talk, don’t be afraid to make it too “easy” to understand. Making a tough topic comprehensible is often the sign that you really understand it, after all, and it’s also a fantastic service to the audience. And also don’t be afraid that your talk isn’t “hard core” enough, because with a diverse enough crowd, there will absolutely be folks for whom it’s still entirely new, and they’ll be thankful.

These were the conclusions I got from talking to a whole range of people at Chaos Communication Camp the weekend before last, and it’s one of the great opportunities when you go to an event like this. At Camp, there were a number of simultaneous stages, and with so many talks that new ones are still being released. That meant that everyone had their chance to say their bit, and many many did.

And that’s great. Because it’s obvious that getting the work done, or diving deep into a particular topic, is part of the hacker experience, but it’s also equally important to share what you’ve gained with the rest of the community. The principle of spreading the knowledge is a cornerstone of our culture, and getting people up to talk about what they’ve learned is the manifestation of this cultural value. If you know something, say something!

Of course, when you’re not at a conference, you could be writing up your hacks and sending them in to the tips line (hint, hint!). That’ll work too.

Teaching A Mini-Tesla To Steer Itself

September 2, 2023 by Dan Maloney 4 Comments

At the risk of stating the obvious, even when you’ve got unlimited resources and access to the best engineering minds, self-driving cars are hard. Building a multi-ton guided missile that can handle the chaotic environment of rush-hour traffic without killing someone is a challenge, to say the least. So if you’re looking to get into the autonomous car game, perhaps it’s best to start small.

If [Austin Blake]’s fun-sized Tesla go-kart looks familiar, it’s probably because we covered the Teskart back when he whipped up this little demon of an EV from a Radio Flyer toy. Adding self-driving to the kart is a natural next step, so [Austin] set off on a journey into machine learning to make it happen. Having settled on behavioral cloning, which trains a model to replicate a behavior by showing it examples of the behavior, he built a bolt-on frame to hold a steering servo made from an electric wheelchair motor, some drive electronics, and a webcam attached to a laptop. Ten or so human-piloted laps around a walking path at a park resulted in a 48,000-image training set, along with the steering wheel angle at each point.

The first go-around wasn’t so great, with the Teskart seemingly bent on going off the track. [Austin] retooled by adding two more webcams, to get a little parallax data and hopefully improve the training data. After a bug fix, the improved model really seemed to do the trick, with the Teskart pretty much keeping in its lane around the track, no matter how fast [Austin] pushed it. Check out the video below to see the Teskart in action.

It’s important to note that this isn’t even close to “Full Self-Driving.” The only thing being controlled is the steering angle; [Austin] is controlling the throttle himself and generally acting as the safety driver should the car veer off course, which it tends to do at one particular junction. But it’s a great first step, and we’re looking forward to further development.

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Make Better 3D Printed Molds, For Thermoforming Plastics

September 2, 2023 by Donald Papp 6 Comments

Thermoforming — which includes vacuum-forming — has its place in a well-rounded workshop, and Mayku (makers of desktop thermoforming machines) have a short list of tips for getting the best results when 3D printing molds on filament-based printers.

A mold is put into direct, prolonged contact with a hot sheet of semi-molten plastic. If one needs a mold to work more than once, there are a few considerations to take into account. The good news is that a few simple guidelines will help get excellent results. Here are the biggest ones:

The smoother the vertical surfaces, the better. Since thermoforming sucks (or pushes) plastic onto and into a mold like a second skin, keeping layer heights between 0.1 mm and 0.2 mm will make de-molding considerably easier.
Generous draft angles. Aim for a 5 degree draft angle. Draft angles of 1-2 degrees are common in injection molding, but a more aggressive one is appropriate due to layer lines giving FDM prints an inherently non-smooth surface.
Thick perimeters and top layers for added strength. The outside of a mold is in contact with the most heat for the longest time. Mayku suggests walls and top layer between 3 mm to 5 mm thick. Don’t forget vent holes!
Use a high infill to better resist stress. Molds need to stand up to mechanical stress as well as heat. Aim for a 50% or higher infill to make a robust part that helps resist deformation.
Ensure your printer can do the job. 3D printing big pieces with high infill can sometimes lift or warp during printing. Use enclosures or draft shields as needed, depending on your printer and material.
Make the mold out of the right material. Mayku recommends that production molds be printed in nylon, which stands up best to the heat and stress a thermoforming mold will be put under. That being said, other materials will work for prototyping. In my experience, even a PLA mold (which deforms readily under thermoforming heat) is good for at least one molding.

Thermoforming open doors for an enterprising hacker, and 3D printing molds is a great complement. If you’re happy being limited to small parts, small “dental” formers like the one pictured here are available from every discount overseas retailer. And of course, thermoforming is great for costumes and props. If you want to get more unusual with your application, how about forming your very own custom-shaped mirrors by thermoforming laminated polystyrene?

RGB Graphics On A DEC Rainbow With Reverse-Engineered Monitor

September 1, 2023 by Maya Posch 12 Comments

One of the delights of the boring pre-VGA era is that you get to express your creativity when it comes to making a random color CRT work with an equally exciting dual CPU computer like the DEC Rainbow 100. This is the situation that the folk over at Usagi Electric found themselves in with a recent project. The Rainbow 100 is an interesting computer in that it can boot not only DOS with its 8088 processor, but also CP/M on the Z80 processor. Although generally used in monochrome mode, it supports a color graphic card to output RGB signals via its male DB15 connector.

DEC Rainbow 100 to Princeton Ultrasync adapter. With strain-relief zip tie.

Unfortunately, the target monitor – a Princeton Ultrasync – featured a female DB25 connector that obviously wasn’t going to connect directly, thus requiring a spot of reverse engineering. Making this very easy, the PCB containing the input connector had the traces clearly marked with the intended signal, which just left the mapping of the two connectors. One complication here was with the Rainbow 100 outputting an RGB signal with sync-on-green, whereas the monitor expected a separate synchronization signal.

Fortunately, most analog monitors aren’t particularly fussy so long as they get the expected signal somewhere in the input, which just left the final issue, of the Rainbow 100 outputting the monochrome signal on a special monochrome pin. This allowed everything to work as it should, and leaving those of us who joined the computing era in the 90s appreciative of standard VGA cables, other than for those weird Sun and Apple systems with their proprietary connectors.

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Labor Day BBQs May Feature NYPD

September 1, 2023 by Kristina Panos 53 Comments

Planning to host a large backyard wingding in the NYC metro area this weekend? Be sure to watch the skies for uninvited guests. That’s right, the NYPD are deploying drones over “large” Labor Day events and yes, even private barbecues. The strategy was announced during a briefing about J’ouvert — that’s a yearly Caribbean festival that marks the end of slavery. It generally brings crowds of thousands and draws a strong police presence to Brooklyn.

While this particular invasion may come as a bit of a shock, this certainly isn’t the first time the NYPD has deployed drones in the name of public safety or in response to emergencies. Data shows they have used them 124 times this year, which is up a staggering 31 times from the four events in 2022.

As you may have guessed, this has invited backlash from privacy and civil liberties advocates. One pointed out that this action “flies in the face of the POST Act,” a city law that requires the NYPD to provide transparency about their various surveillance tactics. The advocates cite the fact that regulations have not kept up with the proliferation of technology.

No matter what happens in the future with regulations, the NYPD can always crash large parties the old fashioned way. Usually, the neighbors will complain at some point, unless they were all invited.

Photo via Unsplash.