A PIC And A Few Passives Support Breakout In Glorious NTSC Color

March 29, 2019 by Dan Maloney 27 Comments

“Never Twice the Same Color” may be an apt pejorative, but supporting analog color TV in the 1950s without abandoning a huge installed base of black-and-white receivers was not an option, and at the end of the day the National Television ~~Standards~~ System Committee did an admirable job working within the constraints they were given.

As a result of the compromises needed, NTSC analog signals are not the easiest to work with, especially when you’re trying to generate them with a microcontroller. This PIC-based breakout-style game manages to accomplish it handily, though, and with a minimal complement of external components. [Jacques] undertook this build as an homage to both the classic Breakout arcade game and the color standard that would drive the home version of the game. In addition to the PIC12F1572 and a crystal oscillator, there are only a few components needed to generate the chroma and luminance signals as well as horizontal and vertical sync. The game itself is fairly true to the original, although a bit twitchy and unforgiving judging by the gameplay video below. [Jacques] has put all the code and schematics up on GitHub for those who wish to revive the analog glory days.

Think NTSC is weird compared to PAL? You’re right, and it’s even weirder than you might know. [Matt] at Stand Up Maths talked about it a while back, and it turns out that a framerate of 29.97 fps actually makes sense when you think it through.

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ESP32 Video Tricks Hack Chat With Bitluni

March 25, 2019 by Dan Maloney 2 Comments

Join us Wednesday at noon Pacific time for the ESP32 Video Tricks Hack Chat!

The projects that bitluni works on have made quite a few appearances on these pages over the last couple of years. Aside from what may or may not have been a street legal electric scooter, most of them have centered around making ESP32s do interesting tricks in the analog world. He’s leveraged the DACs on the chip to create an AM radio transmitter, turned an oscilloscope into a video monitor, and output composite video. That last one was handy for turning a Sony Watchman into a retro game console. He’s also found ways for the ESP32 to output VGA signals. Looks like there’s no end to what he can make the versatile microcontroller do.

Although the conversation could (and probably will) go anywhere, we’ll start with video tricks for the ESP32 and see where it goes from there. Possible topics include:

Tricks for pushing the ESP32 DACs to their limits;
When to use an external DAC;
Optimizing ESP32 code by running on separate cores; and
What about HDMI on the ESP32?

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the ESP32 Video Tricks Hack Chat and we’ll put that in the queue for the Hack Chat discussion.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, March 27, at noon, Pacific time. If time zones have got you down, 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.

An HDMI Input For A Laptop Screen, Minus Laptop

March 14, 2019 by Bryan Cockfield 11 Comments

The lack of HDMI inputs on almost all laptops is a huge drawback for anyone who wants to easily play a video game on the road, for example. As to why no manufacturers offer this piece of convenience when we all have easy access to a working screen of this size, perhaps no one can say. On the other hand, if you want to ditch the rest of the computer, you can make use of the laptop screen for whatever you want.

This project from [Avner] comes to us in a few parts. In the first section, the teardown of the laptop begins and a datasheet for the screen is discovered, which allows [Avner] to prepare an FPGA to drive the screen. The second part involves building an HDMI sink, which is a device which decodes the signal from an HDMI source into its constituent parts so it can be sent to the FPGA. The final section of the project involves actually sending a video to this impressive collection of hardware in order to get a video to appear on the old laptop screen.

This build is worth checking out if you’ve ever dealt with anything involving digital video. It goes into great depth on a lot of the technical details involving HDMI, video devices, and hardware timing issues. This is a great build and, even though we’ve seen similar projects, definitely worth diving into if you have some time on your hands and a spare laptop screen.

DAT, The HD Video Tape Format We Never Knew We Had

February 24, 2019 by Jenny List 48 Comments

When we consume our music online via streaming services it is easy to forget the days of recordings being contained on physical media, and to overlook the plethora of competing formats that vied for space in our hi-fi systems to play them. [Andrew Rossignol] has an eye for dated recording media formats as a chiptune enthusiast though, because not only has he found a DAT machine from the 1990s, he’s hacked it to record HD video rather than hi-fi audio.

If you’ve not encountered DAT before, it’s best to consider the format as the equivalent of a CD player but on a tape cassette. It had its roots in the 1980s, and stored an uncompressed 16-bit CD-quality stereo audio data stream on the tape using a helical-scan mechanism similar to that found in a video cassette recorder. It was extremely expensive due to the complexity of the equipment, the music industry hated it because they thought it would be used to make pirate copies of CDs. But despite those hurdles it established a niche for itself among well-heeled musicians and audiophiles. If any Hackaday readers have encountered a DAT cassette it is most likely to have not contained audio at all but computer data, it was common in the 1990s for servers to use DAT tapes for backup purposes.

[Andrew]’s hack involves using the SPDIF digital interface on his Sony DAT player to carry compressed video data. SPDIF is a mature and well-understood standard that he calculated has a bandwidth of 187.5 kB/s, plenty to carry HD video using the H.265 compression scheme. The SPDIF data is brought into the computer via a USB sound card, and from there his software could either stream or retrieve the video. The stream is encoded into frames following the RFC1662 format to ensure synchronization, and he demonstrates it in the video below with a full explanation.

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Downloadable 3D Cockpits Enhance FPV Racing

February 17, 2019 by Donald Papp 11 Comments

First Person View (or First Person Video) in RC refers to piloting a remote-controlled vehicle or aircraft via a video link, and while serious racers will mount the camera in whatever way offers the best advantage, it’s always fun to mount the camera where a miniature pilot’s head would be, and therefore obtain a more immersive view of the action. [SupermotoXL] is clearly a fan of this approach, and shared downloadable designs for 3D printed cockpit kits for a few models of RC cars, including a more generic assembly for use with other vehicles. The models provide a dash, steering wheel, and even allow for using a small servo to make the steering wheel’s motions match the actual control signals sent. The whole effect is improved further by adding another servo to allow the viewer to pan the camera around.

Check out the video embedded below to see it in action. There are more videos on the project’s page, and check out the project’s photo gallery for more detailed images of the builds.

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Tritium Tesseract Makes A Nifty Nightlight

February 11, 2019 by Lewin Day 27 Comments

As the cube is to three dimensions, the tesseract is to four. Mortals in this universe find it difficult to contemplate four-dimensional geometry, but there are methods of making projections of such heretical shapes in our own limited world. [Sean Hodgins] was interested in the geometry, and decided to build a tesseract featuring everyone’s favourite isotope of hydrogen, tritium.

The build starts with a 3D printed inner and outer frame, sourced in this case from Shapeways in nylon. Both frames have holes which are designed as a friction fit for off-the-shelf tritium vials. These vials use the radioactive decay of tritium with a phosphor coating to create a dim glow which lasts approximately a decade. With the inner frame held inside the outer with the vials acting as structural supports, the inner and outer surfaces are then fitted with semi-transparent mirrored acrylic, creating a nice infinity effect.

It’s a fun trinket that would be perfect as a MacGuffin in any sci-fi film with a weak plot. [Sean] notes that while the tritium glow is disappointingly dim, the device does make a good nightlight. If you’ve built one and get bored with the hypercube, you can always repurpose your tritium vials into a nuclear battery. Video after the break.

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Little FPV Bot Keeps It Simple With An ESP32

February 11, 2019 by Dan Maloney 9 Comments

When it comes to robots, it seems the trend is to make them as complicated as possible – look at anything from Boston Dynamics if you’ve any doubt of that. But there’s plenty to be said for simple robots too, such as this adorable ESP32-driven live-streaming bot.

Now it’s true that [Max.K]’s creation is more remote controlled car than robot, and comparing it to one of the nightmare-fuelling creations of Boston Dynamics is perhaps unfair. But [Max.K]’s new project is itself a simplification and reimagining of his earlier, larger “ZeroBot“. As the name implies, ZeroBot was controlled by a Raspberry Pi Zero, an obvious choice for a mobile platform designed to stream FPV video. The ESP32 bot eschews the Pi platform in favor of, well, an ESP32. To save as much space as possible, [Max.K] did a custom PCB for the microcontroller and its supporting components. The 3D-printed case is nicely designed to hold the board along with two motors, a small VGA camera, and a battery pack. At 160×120 resolution, the video isn’t amazing, but the fact that it can be streamed from the ESP32 at a decent enough framerate to drive the bot using a simple web interface is impressive.

This was a fun project and a very clean, smooth build. We like the lines of this little bot, and wouldn’t mind building one as a quick weekend project ourselves.

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