Building A Bicycle Dash Cam With Advanced Capabilites

November 1, 2021 by 15 Comments

Riding a bicycle is a wonderful and healthy way to get around. However, just like with any other vehicle on the road, it can be useful to have a camera to record what goes on in traffic. [Richard Audette] built just such a rig.

The original setup relies on a Raspberry Pi 3, which takes a photo every 10 seconds using the attached Pi Camera. It then processes these photos using OpenALPR, which is a piece of software for reading licence plates. Licence plates detected while cycling can be stored on the Raspberry Pi for later, something which could be useful in the event of an accident.

However, [Richard] has developed the concept further since then. The revised dashcam adds blind spot detection for added safety, and uses a Luxonis OAK-D camera which provides stereo depth data and has AI acceleration onboard. It’s paired with a laptop carried in a backpack instead of a Raspberry Pi, and can stream video to a smartphone sitting on the handlebars as a sort of rear-view mirror.

Anyone who has commuted on a bicycle will instantly see the value in work like [Richard]’s. Just avoiding one accident from a car coming from behind would be of huge value, and we’re almost surprised we don’t see more bicycle rear view kits in the wild.

Alternatively, if you just want to scan your surroundings as you ride, consider building a landscape scanner instead. Video after the break.

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Smoothing Out Foam Parts With Lots Of Gesso

November 1, 2021 by 16 Comments

Whether you’re building a product mock-up or a lightweight enclosure, carving your parts out of hard foam is a fast way to get the job done. Unfortunately, the end result can have a bit of a rough finish; a problem if you’re looking to attract investors or get some nice shots so you can send your handiwork into Hackaday.

If you ever find yourself in a situation where you need to make a carved piece of foam look like it isn’t a carved piece of foam, this tip from prolific maker [Eric Strebel] could really come in handy. Rather than using some spray-on primer or epoxy coating, things that can be difficult to work with when you’re confined to a small home workspace, he recommends sealing it up with several coats of gesso.

The gesso fills in the tiny voids in the foam’s surface.

For the less artistically inclined in the audience, gesso is essentially a paint that’s been combined with chalk or gypsum to make it thicker. Gesso is generally used to prepare an absorbent surface (such as wood or canvas) before applying paint. In this case, [Eric] is using it to build up the surface of the foam and seal up all the open pores.

The downside is that the gesso requires several coats to really build up. [Eric] puts six coats on in this demonstration before he starts to thin it out a bit with water. At that point, each successive coat is sanded with increasingly higher grits. After nine coats, he does his finish sanding with 600 grit paper, and the results look fantastic.

To add some color [Eric] dyed the piece and then used a toothbrush to flick on some black and white paint, creating a very convincing granite-like finish. Unfortunately, his attempt to brush on a water-based sealer caused this finish to run, and he had to take it all off. In the end, he had to resort to using spray paint to finish the piece, but at least it was a simple rattle can.

This isn’t the first time [Eric] has experimented with alternative priming techniques. He’s a big fan of two-component primer in a can, which lets you lay down a professional finish without the expense and complication of using a spray gun.

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Shall We Play A Game?

November 1, 2021 by 6 Comments

A game show just for hackers like you is coming to the Hackaday Remoticon for the first time this year. Everyone is invited to take part in Hacker Trivia on Friday November 19th at 5 pm Pacific time.

Think of this as a very specialized type of bar trivia. You’re welcome to grab some friends and form a team, or play as a solo act. The biggest difference here is that all of the questions have been drawn up by the wonderful people who write the articles you read every day on Hackaday. To say there is a geeky flair to this is a gross understatement.

Game show host and his producer asking geeky questions
Lewin and Justin during last week’s Hacker Trivia test run with the writing crew as contestants.

Your host for Hacker Trivia is Lewin Day. A staff writer for Hackaday, Lewin has for years dreamed of wearing powder-blue velvet suits, holding note cards full of esoteric questions, while speaking into an oddly-shaped microphone.

We managed to convince him to update the look to that of a modern game show host, and he didn’t disappoint with plans to broadcast from a secret location in Adelaide, Australia along with his producer, Justin McArthur. We’ve made it through a practice run, and I assure you, the game is delightful!

You can tune in live to Hacker Trivia to play along, but we want to make sure that you don’t forget. Sign up for a free ticket to Hackaday Remoticon and we’ll send you a reminder, along with information on how to take part in the online Bring-a-Hack social hour that follows the game show. Beyond these social events, Remoticon also has three keynote speakers, sixteen talk presenters, the Hackaday Prize ceremony, and a Saturday evening party. There’s even a conference ticket purchase option that includes a T-shirt.

Magnesium: Where It Comes From And Why We’re Running Out

November 1, 2021 by 94 Comments

Okay, we’re not running out. We actually have tons of the stuff. But there is a global supply chain crisis. Most of the world’s magnesium is processed in China and several months ago, they just… stopped. In an effort to hit energy consumption quotas, the government of the city of Yulin (where most of the country’s magnesium production takes place) ordered 70% of the smelters to shut down entirely, and the remainder to slash their output by 50%. So, while magnesium remains one of the most abundant elements on the planet, we’re readily running out of processed metal that we can use in manufacturing.

Nikon camera body
The magnesium-alloy body of a Nikon d850. Courtesy of Nikon

But, how do we actually use magnesium in manufacturing anyway? Well, some things are just made from it. It can be mixed with other elements to be made into strong, lightweight alloys that are readily machined and cast. These alloys make up all manner of stuff from race car wheels to camera bodies (and the chassis of the laptop I’m typing this article on). These more direct uses aside, there’s another, larger draw for magnesium that isn’t immediately apparent: aluminum production.

But wait, aluminum, like magnesium is an element. So why would we need magnesium to make it? Rest assured, there’s no alchemy involved- just alloying. Much like magnesium, aluminum is rarely used in its raw form — it’s mixed with other elements to give it desirable properties such as high strength, ductility, toughness, etc. And, as you may have already guessed, most of these alloys require magnesium. Now we’re beginning to paint a larger, scarier picture (and we just missed Halloween!) — a disruption to the world’s aluminum supply.

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core memory

Retro Memory Hack Chat

November 1, 2021 by 6 Comments

Join us on Wednesday, November 3 at noon Pacific for the Retro Memory Hack Chat with Andy Geppert!

With how cheap and easy-to-integrate modern memory chips have become, it’s easy to lose track of the fact that it wasn’t too long ago that memory was the limiting factor in most computer designs. Before the advent of silicon memory, engineers had to make do with all sorts of weird and wonderful technologies just to provide a few precious bytes of memory. Things like intricate webs of wires spangled with ferrite cores, strange acoustic delay lines, and even magnetic bubbles were all tried at one time or another. They worked, at least well enough to get us to the Moon, but none would prove viable in the face of advancements in silicon memory.

That doesn’t mean that retro memory technology doesn’t have a place anymore. Some hobbyists, like Andy Geppert, are keeping the retro memory flame alive. His Core 64 project puts a core memory module in the palm of your hand, and even lets you “draw” directly to memory with a magnet. Andy learned a few tricks along the way to that accomplishment, and wants us all to appreciate the anachronistic charm of retro memory technologies. Stop by the Hack Chat to talk about your memories of memory, or to just learn what it used to take to store a little bit of data.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, November 3 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

An Emulator For OBP, The Spaceflight Computer From The 1960s

November 1, 2021 by 9 Comments

[David Given] frequently dives into retrocomputing, and we don’t just mean he refurbishes old computers. We mean things like creating a simulator and assembler for the OBP spaceflight computer, which was used in the OAO-3 Copernicus space telescope, pictured above. Far from being a niche and forgotten piece of technology, the On-Board Processor (OBP) was used in several spacecraft and succeeded by the Advanced On-board Processor (AOP), which in turn led to the NASA Standard Spaceflight Computer (NSSC-1), used in the Hubble Space Telescope. The OBP was also created entirely from NOR gates, which is pretty neat.

One thing [David] learned in the process is that while this vintage piece of design has its idiosyncrasies, in general, the architecture has many useful features and is pleasant to work with. It is a bit slow, however. It runs at a mere 250 kHz and many instructions take several cycles to complete.

Sample of the natural-language-looking programming syntax for the assembler. (Example from page 68 of the instruction set manual for the OBP.)

One curious thing about the original assembler was documentation showing it was intended to be programmed in a natural-language-looking syntax, of which an example is shown here. To process this, the assembler simply mapped key phrases to specific assembly instructions. As [David] points out, this is an idea that seems to come and go (and indeed the OBP’s successor AOP makes no mention whatsoever of it, so clearly it “went”.) Since a programmer must adhere to a very rigid syntax and structure anyway to make anything work, one might as well just skip dealing with it and write assembly instructions directly, which at least have the benefit of being utterly unambiguous.

We’re not sure who’s up to this level of detail, but embedded below is a video of [David] coding the assembler and OBP emulator, just in case anyone has both an insatiable vintage thirst and a spare eight-and-a-half hours. If you’d prefer just the files, check out the project’s GitHub repository.

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The Pi Zero 2 W Is The Most Efficient Pi

November 1, 2021 by 115 Comments

Last week we saw the announcement of the new Raspberry Pi Zero 2 W, which is basically an improved quad-core version of the Pi Zero — more comparable in speed to the Pi 3B+, but in the smaller Zero form factor. One remarkable aspect of the board is the Raspberry-designed RP3A0 system-in-package, which includes the four CPUs and 512 MB of RAM all on the same chip. While 512 MB of memory is not extravagant by today’s standards, it’s workable. But this custom chip has a secret: it lets the board run on reasonably low power.

When you’re using a Pi Zero, odds are that you’re making a small project, and maybe even one that’s going to run on batteries. The old Pi Zero was great for these self-contained, probably headless, embedded projects: sipping the milliamps slowly. But the cost was significantly slower computation than its bigger brothers. That’s the gap that the Pi Zero 2 W is trying to fill. Can it pull this trick off? Can it run faster, without burning up the batteries? Raspberry Pi sent Hackaday a review unit that I’ve been running through the paces all weekend. We’ll see some benchmarks, measure the power consumption, and find out how the new board does.

The answer turns out to be a qualified “yes”. If you look at mixed CPU-and-memory tasks, the extra efficiency of the RP3A0 lets the Pi Zero 2 W run faster per watt than any of the other Raspberry boards we tested. Most of the time, it runs almost like a Raspberry Pi 3B+, but uses significantly less power.

Along the way, we found some interesting patterns in Raspberry Pi power usage. Indeed, the clickbait title for this article could be “We Soldered a Resistor Inline with Raspberry Pis, and You Won’t Believe What Happened Next”, only that wouldn’t really be clickbait. How many milliamps do you think a Raspberry Pi 4B draws, when it’s shut down? You’re not going to believe it.

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