Trying To Build A Communications Device With A 1-Pound Laser And A 7805

May 20, 2024 by 28 Comments

You can get a red laser diode pretty cheap these days—as cheap as £1 in fact. [Beamer] had purchased one himself, but quickly grew bored with just pointing it at the walls. He decided to figure out if he could use it for some kind of communication, and whipped up a circuit to test it out.

To do the job, he designed a modulator circuit that could drive the laser without damaging it. The build is based around the common 7805 regulator and the venerable 555 timer IC. The 555 is set to pulse at a given rate with the usual array of capacitors and resistors. Its output directly drives the input of a 7805 regulator. It’s set up as a constant current source in order to deliver the correct amount of current to run the laser. The receiver is based around a photodiode, which should prove fairly straightforward.

[Beamer]’s still working on the full setup, but plans to use the laser’s pulses to drive a varying analog meter or something similar. Not every communications method has to send digital data, and it’s good to remember that! Video after the break.

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Etch-A-Sketch Camera Is Open Source

May 20, 2024 by 4 Comments

The Etch-a-Sketch was a great toy if you were somehow born with the talent to use it. For the rest of us, it was a frustrating red brick filled with weird grey sand. [Every Flavor of Robot] has taken the irritating knob-encrusted oblong and turned it into something we can all enjoy, however, by building an Etch-a-Sketch camera!

The build is simple. It uses an ESP32 microcontroller to run the show, equipped with a camera. The camera is used to take a photo of the subject, and the image is then sent to a desktop computer. The desktop runs the image through an AI pipeline that generates a simplified version of the image, and the necessary G-Code to draw it on the Etch-A-Sketch. The toy’s knobs are operated by a pair of brushless motors which have been geared down to provide more torque.

It’s a neat project, and more details are available on GitHub. We’ve seen some other great mechanized Etch-a-Sketch builds before, too.

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Supercon 2023: Exploring The Elegance Of The Voja4

May 20, 2024 by 7 Comments

When you design an electronic badge, the goal is to make a device that’s interesting and has enough depth to keep your attendees engaged for the duration of the con but not so complicated that they can’t become proficient with it before they have to head home. It’s a difficult balance to nail down, and truth be told, not every Supercon badge has stuck the landing in this regard.

But if you’ve really done things right, you’ll create a piece of hardware that manages to outlive the event it was designed for. A badge that attendees continue to explore for months, and potentially even years, afterward. If the talk “Inside the Voja4” by Nathan Jones is any indication, we think it’s safe to say that goal was achieved with the Supercon 2022 badge.

During this forty-minute presentation, Nathan discusses what makes the 4-bit badge so fascinating from a technical standpoint and how it could theoretically be expanded to accomplish far more complex tasks than one might assume at first glance.

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Try Image Classification Running In Your Browser, Thanks To WebGPU

May 20, 2024 by 3 Comments

When something does zero-shot image classification, that means it’s able to make judgments about the contents of an image without the user needing to train the system beforehand on what to look for. Watch it in action with this online demo, which uses WebGPU to implement CLIP (Contrastive Language–Image Pre-training) running in one’s browser, using the input from an attached camera.

By giving the program some natural language visual concept labels (such as ‘person’ or ‘cat’) that fit a hypothetical template for the image content, the system will output — in real-time — its judgement on the appropriateness of such labels to what the camera sees. Again, all of this runs locally.

It’s maybe a little bit unintuitive, but what’s happening in the demo is that the system is deciding which of the user-provided labels (“a photo of a cat” vs “a photo of a bald man”, for example) is most appropriate to what the camera sees. The more a particular label is judged a good fit for the image, the higher the number beside it.

This kind of process benefits greatly from shoveling the hard parts of the computation onto compatible graphics cards, which is exactly what WebGPU provides by allowing the browser access to a local GPU. WebGPU is relatively recent, but we’ve already seen it used to run LLMs (Large Language Models) directly in the browser.

Wondering what makes GPUs so very useful for AI-type applications? It’s all about their ability to work with enormous amounts of data very quickly.

Finding And Resurrecting Archie: The Internet’s First Search Engine

May 20, 2024 by 11 Comments

Back in the innocent days of the late 1980s the Internet as we know it today did not exist yet, but there were still plenty of FTP servers. Since manually keeping track of all of the files on those FTP server would be a royal pain, [Alan Emtage] set to work in 1986 to create an indexing and search service called Archie to streamline this process. As a local tool, it’d regularly fetch the file listing from FTP servers in a list, making this available for easy local search.

After its initial release in 1990, its feature set was expanded to include a World Wide Web crawler by version 3.5 in 1995. Years later, it was assumed that the source for Archie had been lost. That was until the folk over at [The Serial Port] channel managed to track down a still running Archie server in Poland.

The name Archie comes from the word ‘archive’ with the ‘v’ stripped, with no relation to the Archie comics. Even so, this assumption inspired the Gopher search engines Jughead and Veronica. Of these the former is still around, and Veronica’s original database was lost, but a re-implementation of it is still around. Archie itself enjoyed a period of relative commercial success, with [Alan] starting Bunyip Information Systems in 1992 which lasted until 2003. To experience Archie today, [The Serial Port] has the Archie documentation online, along with a live server if you’re feeling like reclaiming the early Internet.

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Radio Caroline At 60

May 19, 2024 by 11 Comments

In the 1960s, if you were a teenager in the United States, a big part of your life was probably music. There was a seemingly endless supply of both radio stations and 45s to keep you entertained. In the UK and other countries, though, the government held a monopoly on broadcasting, and they were not always enthralled with the music kids liked. Where there is demand, there is an opportunity, and several enterprising broadcasters set up radio stations at sea, the so-called pirate radio stations. In 1964, Irish businessman [Ronan O’Rahilly] did just this and founded Radio Caroline. Can you imagine that 60 years later, Radio Caroline is still around?

Not that it has been in operation for 60 years in a row. There were a few years the station’s ship had been impounded by creditors. Then, the ship ran aground on the Goodwin Sands and was damaged. You can see a news short from 1965 in the video below (Radio Caroline shows up at about the 1:50 mark).

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Hackaday Links: May 19, 2024

May 19, 2024 by 4 Comments

If there was one question we heard most often this week, it was “Did you see it?” With “it” referring to the stunning display of aurora borealis — and australis, we assume — on and off for several days. The major outburst here in North America was actually late last week, with aurora extending as far south as Puerto Rico on the night of the tenth. We here in North Idaho were well-situated for prime viewing, but alas, light pollution made things a bit tame without a short drive from the city lights. Totally worth it:

Hat tip to Tom Maloney for the pics. That last one is very reminiscent of what we saw back in 1989 with the geomagnetic storm that knocked Québec’s grid offline, except then the colors were shifted much more toward the red end of the spectrum back then.

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