Probably The Cheapest Lens You Will Ever Use

July 5, 2023 by 23 Comments

Photographic enthusiasts will invariably amass an extensive collection of lenses, and in their communities there are near-mythical and sought-after lenses that change hands for incredible prices. It’s probably the oldest photographic adage though, that the best camera in the world is the one in your hand when the scene presents itself, and probably one of the simplest cameras in the world remains the disposable film camera. Their tiny plastic lenses are not in the same league as the pricey ones, but can they be used by a more serious photographer? [Volzo] set out to find out.

Disposable cameras aren’t the most environmentally friendly items, and he rightly points out that a cheap compact camera can deliver the same in a more sustainable package. There’s also the point to make that the flash capacitor if it has one can deliver a nasty shock, but once past that it’s easy to remove the lens itself.

A single element lens brings with it some significant distortion, and it’s a surprise to find that the focal plane of a disposable camera is curved to take account of that. His first 3D printed mount and adapter for a Sony mirrorless compact camera uses a small aperture to reduce the distortion effects from the edge of the lens but he’s not out of tricks yet. Using a pair of the lenses back-to-back he halves the focal length but further corrects the distortion and delivers a consequent wider angle. Take a look, in the video below.

The result is a usable lens for the toy-camera look on your digital camera, and since the files can all be found at the link above it’s something you can try too. If a disposable camera comes our way, we certainly will.

This isn’t the first disposable camera lens project we’ve brought you.

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A Fuse Is Just A Fuse, Right?

July 5, 2023 by 39 Comments

We like to think that most common electronic components are essentially commodity items. We don´t buy premium wire or resistors. You just assume these electronic components are more or less the same from anywhere unless you need some very special characteristics. What about fuses? We would assume they are all essentially the same, but [Ham Radio A2Z] says he’s throwing away his generic fuses after he found they didn’t work as he would expect.

Of course, name-brand fuses are tested to very specific tests, and you get to see the plots of how the fuses are supposed to melt for Bussmann fuses. Then he takes out a generic assortment of fuses he bought at a hamfest. No Bussmann fuses in that batch!

Comparing the generic fuses with some from Bussmann and Littlefuse, they all work fine to carry current. That isn’t the problem. The problem is when you feed the fuses 20 A and expect them to clear. A 5 A generic fuse carried over 20 A for a very long time, and, as you might expect, it got very hot. We kept waiting for the fuse to blow, but after three minutes, he gave up.

For comparison, a 10 A Bussmann fuse in the same conditions blew almost immediately — about 350 milliseconds. None of the generic fuses blew, and, in fact, the fuse in the video had been subjected to 20 A of over-stress several times already. It seems like it is nearly impossible to blow them at that current level despite it being four times the marked current. Not much of a bargain.

As the video points out, fuses aren’t as much to protect your equipment as much as they are to prevent fires, so don’t forget to include them even on simple projects. Remember the TI 99/4A? The power supply for that vintage computer has an odd little box in the power cable very near the plug. Why? Because they forgot to put a fuse in until the UL reminded them.

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Exploring A New Frontier: Desktop EDM Is Coming

July 5, 2023 by 27 Comments

To say that desktop 3D printing had a transformative effect on our community would be something of an understatement. In just a decade or so, we went from creaky printers that could barely extrude a proper cube to reliable workhorses that don’t cost much more than a decent cordless drill. It’s gotten to the point that it’s almost surprising to see a project grace these pages that doesn’t include 3D printed components in some capacity.

Cooper Zurad

There’s just one problem — everything that comes out of them is plastic. Oh sure, some plastics are stronger than others…but they’re still plastic. Fine for plenty of tasks, but certainly not all. The true revolution for makers and hackers would be a machine that’s as small, convenient, and as easy to use as a desktop 3D printer, but capable of producing metal parts.

If Cooper Zurad has his way such a dream machine might be landing on workbenches in as little as a month, thanks in part to the fact that its built upon the bones of a desktop 3D printer. His open source Powercore device allows nearly any 3D printer to smoothly cut through solid metal using a technique known as electrical discharge machining (EDM). So who better to helm this week’s Desktop EDM Hack Chat?

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Gearing Up With The 2023 Hackaday Prize

July 5, 2023 by 3 Comments

You know how it goes. You’re working on a project, and you need to do some ultra-precise probing, so you end up making a custom PCB probing octopus along the way. Or you find that you spend more time making the jig to hold down a part for machining than you do machining it. Hackers are not merely a tool-using species, we’re a tool-making species – it’s in our nature to want to build the tools that make it easier to get the job done.

The Gearing Up round of the Hackaday Prize celebrates the tool makers. If you’ve got a project that maybe isn’t an end in itself, but rather one of those utility project that can make all the difference, we want to see it here. Maybe it’s obscure measurement gear, maybe it’s a test rig or a bolt sorter, maybe you’ve built your own reflow hot plate. This is the challenge round for you!

The Gearing Up round runs from yesterday, July 4th, until August 8th. As with all of the 2023 Hackaday Prize rounds, ten finalists will receive $500 and get entered for the big prizes to be announced in November. Continue reading “Gearing Up With The 2023 Hackaday Prize” →

A man next to a robot with animatronic eyes and a CRT display showing an audio waveform

Animatronic Alexa Gives Amazon’s Echo A Face

July 5, 2023 by 17 Comments

Today, we’re surrounded by talking computers and clever AI systems that a few decades ago only existed in science fiction. But they definitely looked different back then: instead of a disembodied voice like ChatGPT, classic sci-fi movies typically featured robots that had something resembling a human body, with an actual face you could talk to. [Thomas] over at Workshop Nation thought this human touch was missing from his Amazon Echo, and therefore set out to give Alexa a face in a project he christened Alexatron.

The basic idea was to design a device that would somehow make the Echo’s voice visible and, at the same time, provide a pair of eyes that move in a lifelike manner. For the voice, [Thomas] decided to use the CRT from a small black-and-white TV. By hooking up the Echo’s audio signal to the TV’s vertical deflection circuitry, he turned it into a rudimentary oscilloscope that shows Alexa’s waveform in real time. An acrylic enclosure shields the CRT’s high voltage while keeping everything inside clearly visible.

To complete the face, [Thomas] made a pair of animatronic eyes according to a design by [Will Cogley]. Consisting of just a handful of 3D-printed parts and six servos, it forms a pair of eyes that can move in all directions and blink just like a real person. Thanks to a “person sensor,” which is basically a smart camera that detects faces, the eyes will automatically follow anyone standing in front of the system. The eyes are closed when the system is dormant, but they will open and start looking for faces nearby when the Echo hears its wake word, just like a human or animal responds to its name.

The end result absolutely looks the part: we especially like the eye tracking feature, which gives it that human-like appearance that [Thomas] was aiming for. He isn’t the first person trying to give Alexa a face, though: there are already cute Furbys and creepy bunnies powered by Amazon’s AI, and we’ve even seen Alexa hooked up to an animatronic fish.

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Remote Driving Controversial In UK, But It’s Already Here

July 5, 2023 by 46 Comments

The automotive industry is rushing towards autonomous vehicles as a futuristic ideal. They haven’t got the autonomous part sorted just yet. However, as part of this push, the technology to drive vehicles remotely via video link has become mature.

In the United Kingdom, there has been great controversy on whether this should be allowed, particularly for vehicles piloted by individuals outside the country’s borders. That came to a head with a Law Commission repot published earlier this year, but since then, innovative companies have continued to work on remote driving regardless. Let’s dive in to the current state of play.

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A Faulty Keyboard From A Single LED

July 5, 2023 by 19 Comments

When the chance arrived to buy a mechanical keyboard for not a lot, naturally, [Hales] jumped at it. Then it started having odd intermittent problems with some keys appearing stuck, which led to a teardown and some fault finding. The culprit was a white LED — but why this was the case is a fascinating story.

Stripping it down there didn’t seem to be an obvious culprit, but eventually, the trail led to a lack of diodes in the matrix. This keyboard had an extremely clever yet rather cursed design in which it used LEDs as both illumination and as a diode in the keyboard matrix circuit, and the faulty LED had a reverse breakdown condition that could be triggered under certain operational conditions.

More unexpectedly, it would sometimes hold on to its reverse breakdown state even after power off. Just when you think you understand a component’s properties, there’s always room for surprise. And we can safely say we’ve learned something about the design of cheaper keyboards in reading the account. It’s clear that when it comes to ‘boards, it’s best to take no chances.