Firefox logo displayed on screen

Add WebUSB Support To Firefox With A Special USB Device

March 15, 2025 by 7 Comments
RP2040-based Pico board acting as U2F dongle with Firefox. (Credit: ArcaneNibble, GitHub)
RP2040-based Pico board acting as U2F dongle with Firefox. (Credit: ArcaneNibble, GitHub)

The WebUSB standard is certainly controversial. Many consider it a security risk, and, to date,  only Chromium-based browsers support it. But there is a workaround that is, ironically, supposed to increase security. The adjacent Universal 2nd Factor (U2F) standard also adds (limited) USB support to browsers. Sure, this is meant solely to support U2F USB dongles for two-factor authentication purposes, but as [ArcaneNibble] demonstrates using U2F-compatible firmware on a Raspberry Pi RP2040, by hijacking the U2F payload, this API can be used to provide WebUSB-like functionality.

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You Too Can Do The Franck-Hertz Experiment

March 15, 2025 by 5 Comments

We talk about quantum states — that is, something can be at one of several discrete values but not in between. For example, a binary digit can be a 1 or a 0, but not 0.3 or 0.5. Atoms have quantum states, but how do we know that? That’s what the Franck-Hertz experiment demonstrates, and [stoppi] shows you how to replicate that famous experiment yourself.

You might need to translate the web page if your German isn’t up to speed, but there’s also a video you can watch below. The basic idea is simple. A gas-filled tube sees a large voltage across the cathode and grid. A smaller voltage connects to the grid and anode. If you increase the grid voltage, you might expect the anode current to increase linearly. However, that doesn’t happen. Instead, you’ll observe dips in the anode current.

When electrons reach a certain energy they excite the gas in the tube. This robs them of the energy they need to overcome the grid/anode voltage, which explains the dips. As the energy increases, the current will again start to rise until it manages to excite the gas to the next quantum level, at which point another dip will occur.

Why not build a whole lab? Quantum stuff, at a certain level, is weird, but this experiment seems understandable enough.

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Bar of conductive filament with leds and a battery

Putting Conductive TPU To The Test

March 15, 2025 by 3 Comments

Ever pried apart an LCD? If so, you’ve likely stumbled at the unassuming zebra strip — the pliable connector that makes bridging PCB pads to glass traces look effortless. [Chuck] recently set out to test if he could hack together his own zebra strip using conductive TPU and a 3D printer.

[Chuck] started by printing alternating bands of conductive and non-conductive TPU, aiming to mimic the compressible, striped conductor. Despite careful tuning and slow prints, the results were mixed to say the least. The conductive TPU measured a whopping 16 megaohms, barely touching the definition of conductivity! LEDs stayed dark, multimeters sulked, and frustration mounted. Not one to give up, [Chuck] took to his trusty Proto-pasta conductive PLA, and got bright, blinky success. It left no room for flexibility, though.

It would appear that conductive TPU still isn’t quite ready for prime time in fine-pitch interconnects. But if you find a better filament – or fancy prototyping your own zebra strip – jump in! We’d love to hear about your attempts in the comments.

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My Scammer Girlfriend: Baiting A Romance Fraudster

March 15, 2025 by 21 Comments

Nobody likes spam messages, but some of them contain rather fascinating scams. Case in point, [Ben Tasker] recently got a few romance scam emails that made him decide to take a poke at the scam behind these messages. This particular scam tries to draw in marks with an attached photo (pilfered from Facebook) and fake personal details. Naturally, contacting scammers is a bad idea, and you should never provide them with any personal information if you decide to have some ‘fun’.

The games begin once you contact them via the listed email address, as they’re all sent from hacked/spoofed email accounts. After this you have to wait for the scammers to return to the campaign on their monthly cycle, so give it a few weeks. Analyzing image metadata provides some clues (e.g. the FBMD prefix in IPTC tags set by Meta, as well as timezone info). The IP address from the email headers pointed to a VPN being used, so no easy solution here.

After establishing contact, the scammers try to coax the mark into ‘helping’ them move to their country, with Skype out-call numbers received on [Ben]’s burner phone that seem designed to add to the realism. Then ‘disaster’ strikes and the mark is asked to transfer a lot of money to help their new ‘love’. Naturally, [Ben] wasn’t a gullible mark, and set up a few traps, including a custom domain and website that’d log any visitor (i.e. the scammer).

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Probably The Simplest Sequencing Synth

March 15, 2025 by 31 Comments

With inexpensive microntrollers capable of the most impressive feats of sound synthesis, it’s not so often we see projects that return to an earlier style of electronic music project. The 1-bit synth from [Electroagenda] takes us firmly into that territory, employing that most trusty of circuits, a 555.

It’s a time-honored circuit, a 555 provides a note clock that drives a 4017 that functions as a sequencer. This switches in a set of voltage dividers, which in turn control another 555 oscillator that produces the notes. It’s a fun toy straight from the 1970s, right down to the protoboard and hookup wire construction. There’s a demo video with some lovely beeps below, and we think most of you should have what it takes to make your own.

If you’re seeking more inspiration, may we introduce you to our Logic Noise series?

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Make Your Cheap Thermal Camera Into A Microscope

March 14, 2025 by 17 Comments

[Project 326] has a cheap thermal camera that plugs into a smart phone. Sure they are handy, but what if you could hack one into a microscope with a resolution measured in microns? It is easier than you might think and you can see how in the video below.

Of course, microscopes need lenses, but glass doesn’t usually pass IR very well. This calls for lenses made of exotic material like germanium. One germanium lens gives some magnification. However, using a 3D printed holder, three lenses are in play, and the results are impressive.

The resolution is good enough to see the turns of wire in an incandescent light bulb. A decapsulated power transistor was interesting to view, too. Imaging heat at that much resolution gives you a lot of information. At the end, he teases that using first surface mirrors, he may show how to build an IR telescope as well.

Presumably, this will work with just about any IR camera if you adapt the lens holder. The unit in the video is a UNI-T UTi-260M. So when he says he spent about $35 on the build, that’s not including the $400 or so camera module.

IR imaging can pull off some amazing tricks, like looking inside an IC. If the thermal camera used in the video isn’t to your liking, there are plenty of others out there.

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