Analog Camera Goes Digital

July 15, 2021 by Bryan Cockfield 33 Comments

The digital camera revolution swept through the world in the early 2000s, and aside from some unique situations and a handful of artists still using film, almost everyone has switched over to digital since then. Unfortunately that means that there’s a lot of high quality film cameras in the world that are gathering dust, but with a few pieces of equipment it’s possible to convert them to digital and get some more use out of them.

[befinitiv]’s latest project handles this conversion by swapping in a Raspberry Pi Zero where the film cartridge would otherwise be inserted into the camera. The Pi is attached to a 3D-printed case which mimics the shape of the film, and also houses a Pi camera right in front of the location where the film would be exposed. By removing the Pi camera’s lens, this new setup is able to take advantage of the analog camera’s optics instead and is able to capture images of relatively decent quality.

There are some perks of using this setup as well, namely that video can be broadcast to this phone over a wireless connection to a computer via the Raspberry Pi. It’s a pretty interesting build with excellent results for a remarkably low price tag, and it would be pretty straightforward to interface the camera’s shutter and other control dials into the Raspberry Pi to further replicate the action of an old film camera. And, if you enjoy [befinitiv]’s projects of bringing old tech into the modern world, be sure to check out his 80s-era DOS laptop which is able to run a modern Linux installation.

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Video De-shaker Software Measures Linear Rail Quality

June 27, 2021 by Donald Papp 15 Comments

Here’s an interesting experiment that attempts to measure the quality of a linear rail by using a form of visual odometry, accomplished by mounting a camera on the rail and analyzing the video with open-source software usually used to stabilize shaky video footage. No linear rail is perfect, and it should be possible to measure the degree of imperfection by recording video footage while the camera moves down the length of the rail, and analyzing the result. Imperfections in the rail should cause the video to sway a proportional amount, which would allow one to characterize the rail’s quality.

To test this idea, [Saulius] attached a high-definition camera to a linear rail, pointed the camera towards a high-contrast textured pattern (making the resulting video easier to analyze), and recorded video while moving the camera across the rail at a fixed speed. The resulting video gets fed into the Deshaker plugin for VirtualDub, of which the important part is the deshaker.log file, which contains X, Y, rotate, and zoom correction values required to stabilize the video. [Saulius] used these values to create a graph characterizing the linear rail’s quality.

It’s a clever proof of concept, especially in how it uses no special tools and leverages a video stabilizing algorithm in an unusual way. However, the results aren’t exactly easy to turn into concrete, real-world measurements. Turning image results into micrometers is a matter of counting pixels, and for this task video stabilizing is an imperfect tool, since the algorithm prioritizes visual results instead of absolute measurements. Still, it’s an interesting experiment, and perfectly capable of measuring rail quality in a relative sense. Can’t help but be a bit curious about how it would profile something like these cardboard CNC modules.

VGA From Scratch On A Homebrew 8-bit Computer

June 21, 2021 by Bryan Cockfield 9 Comments

[James Sharman] has built an impressive 8-bit homebrew computer. Based on TTL logic chips, it has a pipelined design which makes it capable of Commodore-level computing, but [James] hasn’t quite finished everything yet. While it is currently built on its own custom PCB, it has a limiting LCD display which isn’t up to the standards of the rest of the build. To resolve this issue, he decided to implement VGA from scratch.

This isn’t a bit-bang VGA implementation, either. He plans for full resolution (640×480) which will push the limits of his hardware. He also sets goals of a 24-bit DAC which will allow for millions of colors, the ability to use sprites, and hardware scrolling. Since he’s doing all of this from scratch, the plan is to keep it as simple as possible and make gradual improvements to the build as he goes. To that end, the first iteration uses a single latching chip with some other passive components. After adding some code to the CPU to support the new video style, [James] is able to display an image on his monitor.

While the image of the parrot he’s displaying isn’t exactly perfect yet, it’s a great start for his build and he does plan to make improvements to it in future videos. We’d say he’s well on his way to reproducing a full 8-bit retrocomputer. Although VGA is long outdated for modern computers, the standard is straightforward to implement and limited versions can even be done with very small microcontrollers.

Thanks to [BaldPower] for the tip!

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Formula 1 TV Broadcasting In 1:87 Scale

June 18, 2021 by Chris Lott 11 Comments

[Gerrit Braun], co-founder of the [Miniatur Wunderland] model railway and miniature airport attraction in Hamburg, takes his model building seriously. For more than five years, he and his team have been meticulously planning, testing, and building a 1:87 scale of Formula 1’s Monaco Grand Prix. Models at the Wunderland are crafted to the Nth detail and all reasonable efforts, and some unreasonable ones, are taken to achieve true-to-life results. In the video down below, part of Gerrit’s diary of the project, he discusses the issues and solutions to simulating realistic television broadcasts (the video is in German, but it has English language subtitles).

The goal is to model the large billboard-sized monitor screens set up at viewing stands. In real life, these displays are fed with images coming in from cameras located all over the circuit, the majority of which are operated by a cameraman. The miniaturization of cameras has come a long way in recent years — the ESP32-CAM module or the Raspberry Pi cameras, for example. But miniaturizing the pan-and-tilt actions of a cameraman, while perhaps possible, would not be reliable over the long time (these exhibits at Wunderland are permanent and operate almost daily). Instead, the team is able to use software to extract a cropped window from high-resolution video, and moving the position of this cropped window simulates the pointing of the camera. More details are in the video.

The skill and creativity of [Gerrit] and his team is incredible. Other videos on this project cover topics like the sound system, PCB techniques used for the roads, and the eye-popping use of an electric standing desk to lift an entire city block so workers can gain access to the area. Fair warning — these are addictive, and the video below is #76 of an unfinished series. We wrote about Wunderland back in 2016 when [Gerrit] and his twin brother [Frank] teamed with Google Maps to make a street view of their replica cities. Thanks to [Conductiveinsulation] who sent us the tip, saying that the discussion about interconnected triangular PCB tiles on this week’s Podcast #122 reminded him of this for some reason. Have any of our readers visited Miniatur Wunderland before? Let us know in the comments below.

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VGA Library For The Raspberry Pi Pico

June 11, 2021 by Chris Lott 11 Comments

[Miroslav Nemecek] really pushes the limits of the Pico with his PicoVGA project, which packs a surprising number of features. His main goal with this library is to run retro games which can fit within the limited RAM and processing power of the Pico, but the demo video below shows a wide array of potential applications.

The library provides a whole slew of features, including frame buffering, sprites, overlays, and resolutions up to 1280×960 in either NTSC or PAL timings. A PWM-driven audio output channel is also included in the package. His library takes full advantage of the programmable I/O module functionality and uses the second core which is dedicated to video processing. However, with care, the second core can perform application tasks in certain circumstances. The VGA analog output signals are provided by resistor ladders, and pixel color is 8-bit R3G3B2 format. To be clear, [Miroslav] does cheat a little bit here in one regard — he overclocks the processor up to 270 MHz to meet the timing demands in some of the resolutions.

[Miroslav] has developed these tools using ARM-GCC on Windows, but he lacks the experience to make a Linux build. He welcomes help on that front from anyone familiar with Linux. And stay tuned — there may be more coming from [Miroslav] in the future. He notes that the PicoVGA library was created as part of a retro gaming computer project which is still under development. We look forward to hearing more about this when it gets released.

A couple of weeks ago we wrote about a monochrome VGA version of Pong for the Pico by [Nick Bild]. It’s exciting to see these projects which are exploring the limits of the Pico’s capabilities. Have you seen any boundary-pushing applications for the Pico? Let us know in the comments below. Thanks to [Pavel Krivanek] for sending this project to our tip line.

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Putting Perseverance Rover’s View Into Satellite View Context

March 30, 2021 by Roger Cheng 3 Comments

It’s always fun to look over aerial and satellite maps of places we know, seeing a perspective different from our usual ground level view. We lose that context when it’s a place we don’t know by heart. Such as, say, Mars. So [Matthew Earl] sought to give Perseverance rover’s landing video some context by projecting onto orbital imagery from ESA’s Mars Express. The resulting video (embedded below the break) is a fun watch alongside the technical writeup Reprojecting the Perseverance landing footage onto satellite imagery.

Some telemetry of rover position and orientation were transmitted live during the landing process, with the rest recorded and downloaded later. Surprisingly, none of that information was used for this project, which was based entirely on video pixels. This makes the results even more impressive and the techniques more widely applicable to other projects. The foundational piece is SIFT (Scale Invariant Feature Transform), which is one of many tools in the OpenCV toolbox. SIFT found correlations between Perseverance’s video frames and Mars Express orbital image, feeding into a processing pipeline written in Python for results rendered in Blender.

While many elements of this project sound enticing for applications in robot vision, there are a few challenges touched upon in the “Final Touches” section of the writeup. The falling heatshield interfered with automated tracking, implying this process will need help to properly understand dynamically changing environments. Furthermore, it does not seem to run fast enough for a robot’s real-time needs. But at first glance, these problems are not fundamental. They merely await some motivated people to tackle in the future.

This process bears some superficial similarities to projection mapping, which is a category of projects we’ve featured on these pages. Except everything is reversed (camera instead of video projector, etc.) making the math an entirely different can of worms. But if projection mapping sounds more to your interest, here is a starting point.

[via Dr. Tanya Harrison @TanyaOfMars]

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Retro Recreations Hack Chat With Tube Time

March 15, 2021 by Dan Maloney 2 Comments

Join us on Wednesday, March 17 at noon Pacific for the Retro Recreations Hack Chat with Tube Time!

Nostalgia seems to be an inevitable consequence of progress. Advance any field far enough into the future, and eventually someone will look back with misty eyes and fond memories of the good old days and start the process of turning what would qualify as junk under normal conditions into highly desirable collectibles.

In some ways, those who have been bitten by the computer nostalgia bug are lucky, since the sheer number of artifacts produced during their period of interest is likely to be pretty high, making getting gear to lovingly restore relatively easy. But even products produced in their millions can eventually get difficult to find, especially once they get snapped up by eager collectors, leaving the rest to make do or do without.

Of course, if you’re as resourceful as Tube Time is, there’s another alternative: build your own retro recreations. He has embarked on some pretty intense builds to recapture a little of what early computer enthusiasts went through trying to build useful machines. He has built replicas of early PC sound cards, like an ISA-bus AdLib card, its MCA equivalent, and the “Snark Barker”— or is it the “Snood Bloober”? — which bears an uncanny resemblance to the classic Sound Blaster card from the 1980s.

Tube Time will join us for the Hack Chat this week to answer questions about all his retro recreations, including his newest work on a retro video card. Be sure to bring your questions on retro rebuilds, reverse engineering, and general computer nostalgia to the chat.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, March 17 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
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