VHS-Decode Project Could Help Archival Efforts

December 13, 2022 by Lewin Day 47 Comments

Archiving data from old storage media can be a highly complex process. It can be as simple as putting a disk in an old drive and reading out the contents. These days, though, the state of the art is more complex, with advanced techniques helping to recover the most data possible. The VHS-Decode project is an effort to improve the archiving of old analog video tapes.

The project is a fork of the LaserDisc-focused ld-decode, started by [Chad Page] back in 2013, which readers may recall was used for the Domesday Duplicator — a device aimed to recover data from the BBC’s ancient Domesday LaserDiscs. VHS-Decode is designed to capture the raw RF signals straight out of a tape head, which are the most direct representation of the signals on the physical media. From there, these signals can be processed in various ways to best recover the original audio and video tracks. It’s much the same technique as is used by floppy disk recovery tools like the FluxEngine.

Despite the VHS name, the code currently works with several tape formats. VHS, S-VHS and U-Matic are supported in PAL and NTSC formats, while Betamax, Video8 and High8 tape capture remains a work in progress. Using the code requires a video tape player with test points or traces that make signals from the head accessible. Capturing those signals is achieved via a Domesday Duplicator hardware device, or alternatively a Conexant CX2388x analog-to-digital converter, often found in many old PCI TV tuner cards. Various techniques can then be used to turn the captured signals into watchable video files.

We love a good archival project, and VHS-Decode is clearly a useful tool when it comes to salvaging old video tapes. Continue reading “VHS-Decode Project Could Help Archival Efforts” →

Start Your Engines: The FPV Contest Begins Now!

November 22, 2022 by Elliot Williams 15 Comments

There are places that you can go in person, but for everything else, there’s FPV. Whether you’re flying race quads, diving the depths in a yellow submarine, or simply roving the surface of the land, we want to see your builds. If it’s remote controlled, and you feel like you’re in the pilot’s seat, it’s FPV.

When you say “first person view” many of you will instinctively follow up with “flight” or “drone”. But given the ease of adding a camera and remote control to almost any vehicle, there’s no reason to only fly the FPV skies. (Of course, we want to see your crazy quadcopter builds too.)

We went looking for a few less-traditional examples to whet your appetite, and we found a lot. There are super-cute FPV bots for indoors and more robust tanks for cruising around the neighborhood. In the summer, you’ll probably need an FPV lawnmower, and for the winter, naturally, an FPV snowblower or a budget-friendly FPV snow-boat. Or skip the outdoors entirely and terrorize the pool with an FPV sub.

This contest isn’t exclusively about the vehicles either. If you’re working on the tech that makes FPV possible, we want you to enter. For instance, this simple quad/drone tracker will help keep your video feed running and your mind on flying. This cockpit will make the immersion more complete. And nobody likes the jello-cam effect that excess vibration can cause, so we’d like to see camera hacks as well.

And of course, your quads. Is your FPV quad too fast, too light, or does it fly too far? Show us. The contest starts now and runs until Jan 3, 2023, and there are three $150 shopping sprees courtesy of Digi-Key on the line. Get hacking!

A CRT Monitor From An Obsolete Logic Analyzer

October 7, 2022 by Jenny List 15 Comments

The designers of older equipment that contained a CRT monitor rarely made the effort to design their own driver and deflection circuitry. Instead they were more likely to buy an off the shelf assembly from a monitor manufacturer, and simply supply it with their video. [TomV] has an old HP 16500A logic analyzer, and in it he found a Sony monitor chassis. With a quest for a microfiche service manual and a bit of reverse engineering, he was able to hook it up to a VGA port and use it as an extension monitor for his laptop.

The monitor chassis is a Sony CHM-9001-00, which sports their 10″ Trinitron tube. These were among the very best CRT tubes of the day, making it the type of module 1990s hacker would have been very pleased to get their hands on. Here in 2022 a look at the monitor’s 40-pin connector reveals a standard RGB interface which the service manual confirms is within the voltage range to be driven from a VGA output. A Thinkpad X220 is pressed into service, with a 576 by 360 pixel at 60 Hz video mode defined, and there we have it, a modern desktop on an obsolete piece of test equipment.

The intended destination for this monitor is a small arcade cabinet, so it needed to be independent of the HP chassis. The required 120 VDC supply comes from an inverter designed for solar battery charging, which balked at the inrush current from the monitor when fed with 12 V. Increasing the supply voltage on the low voltage side solved that, leading to a very serviceable monitor. We have no use for one, but we’d be lying if we said we didn’t want one.

Perhaps you may have wondered, what made Trinitrons so good?

Hackaday Prize 2022: A Spring-Driven Digital Movie Camera

September 1, 2022 by Lewin Day 14 Comments

These days, most of us are carrying capable smartphones with high-quality cameras. It makes shooting video so easy as to take all the fun out of it. [AIRPOCKET] decided to bring that back, by converting an old spring-driven 8mm film camera to shoot digital video.

The camera in question is a magazine-fed Bell & Howell Model 172 from the 1950s. In its original spring-driven form, it could shoot for approximately 35 seconds at a (jerky) frame rate 16 fps.

In this build, though, the film is replaced with a digital imaging system designed to fit in the same space as the original magazine. A Raspberry Pi Zero 2 was pressed into service, along with a rechargeable battery and Pi camera module. The camera is timed to synchronise with the shutter mechanism via a photosensor.

Since it uses the original optics and shutter speed, the resulting video is actually very reminiscent of the Super 8 cameras of the past. It’s an impressive way to get a retro film effect straight into a digital output format. The alternative is to just shoot on film and scan it afterwards, of course! Video after the break.

Continue reading “Hackaday Prize 2022: A Spring-Driven Digital Movie Camera” →

This Simple Media Player Will Inspire Beginners And Invite Experimentation

August 16, 2022 by Dan Maloney 4 Comments

While it would have been considered science-fiction just a few decades ago, the ability to watch virtually any movie or TV show on a little slab that fits in your pocket is today no big deal. But for an electronics beginner, being able to put together a pocketable video player like this one would be quite exciting, and might even serve as a gateway into the larger world of electronics design.

For inspiration, [Alex] from Super Make Something on YouTube looked to the Rickrolling keychain media players we featured back in January. His player is quite a bit larger and more capable, with a PCB design that allows the player to be built in multiple configurations, from audio-only to full video and a LiPo battery. The guts of the player center around an ESP32 module, with an audio amp and speakers plus a 1.8″ LCD screen with SD card reader for storing media files. Add in a few controls and switches and a little code, and you’ll be playing back media files in a snap. Build info and demo in the video below.

It may be a simple design, but we feel like that’s the whole point. [Alex] has taken pains to make this as approachable a build as possible. All the parts are cheap and easily available, and the skills needed to put it together are minimal — with the possible exception of soldering down the ESP32 module, which lacks castellated edge terminals. For a beginner, getting a usable media player by mixing together just a few modules would be magical, and the fact that it’s still pretty hackable afterward is just icing on the cake.

Continue reading “This Simple Media Player Will Inspire Beginners And Invite Experimentation” →

Think You Know How Mario Kart Works?

July 4, 2022 by Elliot Williams 3 Comments

In what looks like the kickoff of a fun video series, [MrL314] takes us on a quick but deep tour of how the AI in Mario Kart works. (Video, embedded below.) Don’t play much Mario Kart anymore? Well, have a look anyway because some of the very simple tricks that make Bowser pass Princess Peach without running into her might be useful in any manner of pre-programmed navigation scenarios.

Quick spoilers. The CPU players move through different zones, each with a desired speed and a vector direction field that changes the direction they should point in. Only when they run off course do they actually compute headings to their target. Setting this desired direction and speed beforehand greatly reduces the on-the-fly computation needed.

Then you throw other players into the mix, and a very simple distance-dependant turning algorithm makes for clean overtaking. This effect is hand-tweaked for the particular racecourse, though, because you don’t want Luigi driving off the thin stretches on Rainbow Road. For more technical details, you can check out [MrL314]’s notes.

If anything, this video gives us a further appreciation of the clever little hacks that create apparently complex interactions from tremendously simple rules. Remember Mario Kart when you’re programming in that next multi-gigabyte neural network model, OK?

Continue reading “Think You Know How Mario Kart Works?” →

Raspberry Pi Simulates The Real Analog TV Experience

June 20, 2022 by Dan Maloney 18 Comments

If you’ve laid hands on a retro analog TV, have the restoration bug, and you plan to make the final project at least somewhat period-correct, you face a bit of a conundrum: what are you going to watch? Sure, you can serve up just about any content digitally these days, but some programs just don’t feel right on an old TV. And even if you do get suitably retro programming, streaming isn’t quite the same as the experience of tuning your way through the somewhat meager selections as we did back in the analog days.

But don’t worry — this Raspberry Pi TV simulator can make your streaming experience just like the analog TV experience of yore. It comes to us from [Rodrigo], who found a slightly abused 5″ black-and-white portable TV that was just right for the modification. The battery compartment underneath the set made the perfect place to mount a Pi, which takes care of streaming a variety of old movies and shorts. The position of the original tuning potentiometer is read by an Arduino, which tells the Pi which “channel” you’re currently tuned to.

Composite video is fed from the Pi’s output right into the TV’s video input, and the image quality is just about what you’d expect. But for our money, the thing that really sells this is the use of a relay to switch the TV’s tuner back into the circuit for a short bit between channel changes. This gives a realistic burst of static and snow, just like we endured in the old days. Hats off to [Rodrigo] for capturing everything that was awful about TV back in the day — Mesa of Lost Women, indeed! — but still managing to make it look good.

Continue reading “Raspberry Pi Simulates The Real Analog TV Experience” →