Doing 1080p Video, Sort Of, On The STM32 Microcontroller

September 30, 2024 by Lewin Day 12 Comments

When you think 1080p video, you probably don’t think STM32 microcontroller. And yet! [Gabriel Cséfalvay] has pulled off just that through the creative use of on-chip peripherals. Sort of.

The build is based around the STM32L4P5—far from the hottest chip in the world. Depending on the exact part you pick, it offers 512 KB or 1 Mbyte of flash memory, 320 KB of SRAM, and runs at 120 MHz. Not bad, but not stellar.

Still, [Gabriel] was able to push 1080p at a sort of half resolution. Basically, the chip is generating a 1080p widescreen RGB VGA signal. However, to get around the limited RAM of the chip, [Gabriel] had to implement a hack—basically, every pixel is RAM rendered as 2×2 pixels to make up the full-sized display. At this stage, true 1080p looks achievable, but it’ll be a further challenge to properly fit it into memory.

Output hardware is minimal. One pin puts out the HSYNC signal, another handles VSYNC. The same pixel data is clocked out over R, G, and B signals, making all the pixels either white or black. Clocking out the data is handled by a nifty combination of the onboard DMA functionality and the OCTOSPI hardware. This enables the chip to hit the necessary data rate to generate such a high-resolution display.

There’s more work to be done, but it’s neat to see [Gabriel] get even this far with such limited hardware. We’ve seen others theorize similar feats on chips like the RP2040 in the Pi Pico, too. Video after the break.

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Static Electricity And The Machines That Make It

September 30, 2024 by Lewin Day 20 Comments

Static electricity often just seems like an everyday annoyance when a wool sweater crackles as you pull it off, or when a doorknob delivers an unexpected zap. Regardless, the phenomenon is much more fascinating and complex than these simple examples suggest. In fact, static electricity is direct observable evidence of the actions of subatomic particles and the charges they carry.

While zaps from a fuzzy carpet or playground slide are funny, humanity has learned how to harness this naturally occurring force in far more deliberate and intriguing ways. In this article, we’ll dive into some of the most iconic machines that generate static electricity and explore how they work.

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Making A Split-Anode Magnetron

September 26, 2024 by Dave Rowntree 3 Comments

YouTuber The Science Furry has been attempting to make a split-anode magnetron and, after earlier failures, is having another crack at it. This also failed, but they’ve learned where to focus their efforts for the future, and it sure is fun to follow along.

The magnetron theory is simple enough, and we’ve covered this many times, but the split anode arrangement differs slightly from the microwave in your kitchen. The idea is to make a heated filament the cathode, so electrons are ejected from the hot surface by thermionic emission. These are forced into a spiral path using a perpendicular magnetic field. This is a result of the Lorentz force. A simple pair of magnets external to the tube is all that is needed for that. Depending on the diameter of the cavity and the gap width, a standing wave will be emitted. The anodes must be supplied with an alternating potential for this arrangement to work. This causes the electrons to ‘bunch up’ as they cross the gaps, producing the required RF oscillation. The split electrodes also allow an inductor to be added to tune the frequency of this standing wave. That is what makes this special.

The construction starts with pre-made end seals with the tungsten wire electrode wire passing through. In the first video, they attempted to coat the cathode with barium nitrate, but this flaked off, ruining the tube. The second attempt replaces the coiled filament with a straight wire and uses a coating paste made from Barium Carbonate mixed with nitrocellulose in a bit of acetone. When heated, the nitrocellulose and the carbonate will decompose, hopefully leaving the barium coating intact. After inserting the electrode assembly into a section of a test tube and welding on the ends, the vacuum could be pulled and sealed off. After preheating the cathode, some gasses will be emitted into the vacuum, which is then adsorbed into a nearby titanium wire getter. At least, that’s the theory.

Upon testing, this second version burned out early on for an unknown reason, so they tried again, this time with an uncoated cathode. Measuring the emission current showed only 50 uA, which is nowhere near enough, and making the filament this hot caused it to boil off and coat the tube! They decide that perhaps this is one step too many and need to experiment with the barium coating by making simpler diode tubes to get the hang of the process!

If this stuff is over your head, you need a quick history lesson about the magnetron. Next check out this teardown. Finally, we have covered DIY magnetrons before, like this excellent DIY magnetron-powered plasma sputtering device. Yes, you read that correctly.

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Hack On Self: Collecting Data

September 16, 2024 by Arya Voronova 11 Comments

A month ago, I’ve talked about using computers to hack on our day-to-day existence, specifically, augmenting my sense of time (or rather, lack thereof). Collecting data has been super helpful – and it’s best to automate it as much as possible. Furthermore, an augment can’t be annoying beyond the level you expect, and making it context-sensitive is important – the augment needs to understand whether it’s the right time to activate.

I want to talk about context sensitivity – it’s one of the aspects that brings us closest to the sci-fi future; currently, in some good ways and many bad ways. Your device needs to know what’s happening around it, which means that you need to give it data beyond what the augment itself is able to collect. Let me show you how you can extract fun insights from collecting data, with an example of a data source you can easily tap while on your computer, talk about implications of data collections, and why you should do it despite everything.

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Hack Your Eyesight With High Tech Bifocals

September 16, 2024 by Al Williams 32 Comments

As we get older, our eyes get worse. That’s just a fact of life. It is a rite of passage the first time you leave the eye doctor with a script for “progressive” lenses which are just fancy bifocals. However, a new high-tech version of bifocals promises you better vision, but with a slight drawback, as [Sherri L. Smith] found.

Remember how users of Google Glass earned the nickname “glassholes?” Well, these new bifocals make Google Glass look like a fashion statement. If you are too young to need them, bifocals account for the fact that your eyes need different kinds of help when you look close up (like soldering) or far away (like at an antenna up on a roof). A true bifocal has two lenses and you quickly learn to look down at anything close up and up to see things far away. Progressives work the same, but they transition between the two settings instead of having a discrete mini lens at the bottom.

The new glasses, the ViXion01 change based on what you are looking for. They measure range and adjust accordingly. For $555, or a monthly rental, you can wear what looks like a prototype for a Star Trek visor and let it deduce what you are looking at and change its lenses accordingly.

Of course, this takes batteries that last about ten hours. It also requires medical approval to be real glasses and it doesn’t have that, yet. Honestly, if they worked well and didn’t look so dorky, the real use case might be allowing your eye doctor to immediately download a new setting as your vision changes. How about you? How much odd headgear are you willing to wear in public and why?

Glasses have a long strange history. While a university prototype we saw earlier was not likely to win fashion awards, they did look better than these. Maybe.

Soldering, Up Close And Personal

September 14, 2024 by Dan Maloney 13 Comments

A word of warning before watching this very cool video on soldering: it may make you greatly desire what appears to be a very, very expensive microscope. You’ve been warned.

Granted, most people don’t really need to get this up close and personal with their soldering, but as [Robert Feranec] points out, a close look at what’s going on when the solder melts and the flux flows can be a real eye-opener. The video starts with what might be the most esoteric soldering situation — a ball-grid array (BGA) chip. It also happens to be one of the hardest techniques to assess visually, both during reflow and afterward to check the quality of your work. While the microscope [Robert] uses, a Keyence VHX-7000 series digital scope, allows the objective to swivel around and over the subject in multiple axes and keep track of where it is while doing it, it falls short of being the X-ray vision you’d need to see much beyond the outermost rows of balls. But, being able to look in at an angle is a huge benefit, one that allows us a glimpse of the reflow process.

More after the break

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Pulling Apart An Old Satellite Truck Tracker

September 13, 2024 by Lewin Day 9 Comments

Sometimes there’s nothing more rewarding than pulling apart an old piece of hardware of mysterious origin. [saveitforparts] does just that, and recently came across a curious satellite system from a surplus store. What else could he do, other than tear it down and try to get it humming?

The device appeared to be satellite communication device for a tracking unit of some sort, complete with a long, thick proprietary cable. That led to a junction box with a serial port and an RJ45 port, along with some other interfaces. Disassembly of the unit revealed it contained a great deal of smarts onboard, including some kind of single-board computer. Comms-wise, it featured a cellular GPRS interface as well as an Orbcomm satellite modem. It also packed in GPS, WiFi, Xbee, Ethernet, and serial interfaces. It ultimately turned out to be a Digi ConnectPort X5 device, used as a satellite tracking system for commercial trucks.

What’s cool is that the video doesn’t just cover pulling it apart. It also dives into communicating with the unit. [saveitforparts] was able to power it up and, using the manufacturer’s software, actually talk to the device. He even found the web interface and tested the satellite modem.

Ultimately, this is the kind of obscure industry hardware that most of us would never come into contact with during our regular lives. It’s neat when these things show up on the secondary market so hackers can pull them apart and see what makes them tick. Video after the break.

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