qr code

50 Articles

Streaming Deck Removes Need For Dedicated Hardware

February 25, 2024 by 11 Comments

Streaming content online has never been more popular than it is now, from YouTube to Twitch there are all kinds of creators around with interesting streams across a wide spectrum of interests. With that gold rush comes plenty of people selling figurative shovels as well, with audio mixing gear, high-quality web cams, and dedicated devices for controlling all of this technology. Often these devices take the form of a tablet-like device, but [Lenochxd] thinks that any tablet ought to be able to perform this task without needing dedicated, often proprietary, hardware.

The solution offered here is called WebDeck, an application written in Flask that turns essentially any device with a broswer into a stream control device. Of course it helps to have a touch screen as well, but an abundance of tablets and smartphones in the world makes this a non-issue. With the software running on the host computer, the streamer can control various aspects of that computer remotely by scanning a QR code which opens a browser window with all of the controls accessible from within. It has support for VLC, OBS Studio, and Spotify as well which covers the bases for plenty of streaming needs.

Currently the host software only runs on Windows, but [Lenochxd] hopes to have MacOS and Linux versions available soon. We’re always in favor of any device that uses existing technology and also avoids proprietary hardware and software. Hopefully that’s a recipe to avoid planned obsolescence and unnecessary production. If you prefer a version with a little bit of tactile feedback, though, we’ve seen other decks which add physical buttons for quick control of the stream.

Unlimited Cloud Storage YouTube Style

February 22, 2024 by 74 Comments

[Adam Conway] wanted to store files in the cloud. However, if you haven’t noticed, unlimited free storage is hard to find. We aren’t sure if he wants to use the tool he built seriously, but he decided that if he could encode data in a video format, he could store his files on YouTube. Does it work? It does, and you can find the code on GitHub.

Of course, the efficiency isn’t very good. A 7 K image, for example, yielded a 9-megabyte video. If we were going to store files on YouTube, we’d encrypt them, too, making it even worse.

The first attempt was to break the file into pieces and encode them as QR codes. Makes sense, but it didn’t work out. To get enough data into each frame, the modules (think pixels) in the QR code were small. Combined with video compression, the system was unreliable.

Simplicity rules. Each frame is 1920×1080 and uses a black pixel as a one and a white pixel as a zero. In theory, this gives about 259 kbytes per frame. However, to help avoid problems decoding due to video compression, the real bits use a 5×5 pixel block, so that means you get about 10 kbytes of data per frame.

The code isn’t perfect. It can add things to the end of a file, for example, but that would be easy to fix. The protocol could use error correction and compression. You might even build encryption into it or store more data — old school cassette-style — using the audio channel. Still, as a proof of concept, it is pretty neat.

This might sound like a new idea, but people way back in the early home computer days could back up data to VCRs. This isn’t even the first time we’ve seen it done with YouTube.

Recreating The Quadrophonic Sound Of The 70s

February 6, 2024 by 23 Comments

For plenty of media center PCs, home theaters, and people with a simple TV and a decent audio system, the standard speaker setup now is 5.1 surround sound. Left and right speakers in the front and back, with a center speaker and a subwoofer. But the 5.1 setup wasn’t always the standard (and still isn’t the only standard); after stereo was adopted mid-century, audio engineers wanted more than just two channels and briefly attempted a four-channel system called quadrophonic sound. There’s still some media from the 70s that can be found that is built for this system, such as [Alan]’s collection of 8-track tapes. These tapes are getting along in years, so he built a quadrophonic 8-track replica to keep the experience alive.

The first thing needed for a replica system like this is digital quadrophonic audio files themselves. Since the format died in the late 70s, there’s not a lot available in modern times so [Alan] has a dedicated 8-track player connected to a four-channel audio-to-USB device to digitize his own collection of quadrophonic 8-track tapes. This process is destructive for the decades-old tapes so it is very much necessary.

With the audio files captured, he now needs something to play them back with. A Raspberry Pi is put to the task, but it needs a special sound card in order to play back the four channels simultaneously. To preserve the feel of an antique 8-track player he’s cannibalized parts from three broken players to keep the cassette loading mechanism and track indicator display along with four VU meters for each of the channels. A QR code reader inside the device reads a QR code on the replica 8-track cassettes when they are inserted which prompts the Pi to play the correct audio file, and a series of buttons along with a screen on the front can be used to fast forward, rewind and pause. A solenoid inside the device preserves the “clunk” sound typical of real 8-track players.

As a replica, this player goes to great lengths to preserve the essence of not only the 8-track era, but the brief quadrophonic frenzy of the early and mid 70s. There’s not a lot of activity around quadrophonic sound anymore, but 8-tracks are popular targets for builds and restorations, and a few that go beyond audio including this project that uses one for computer memory instead.

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Read QR Codes Without A Computer

January 22, 2024 by 21 Comments

Did you ever watch Star Wars and wondered how people understood what R2D2 was saying? Maybe [Luke Skywalker] would enjoy learning to decode QR Codes by hand, too. While it might not be very practical, it would be a good party trick — assuming, like us, you party with nerds.

You can start by scanning a code, or the site will create one according to your specifications or generate one randomly. It then takes the selected code and shows you how it is put together. Fun fact: 21×21 “modules” (QR-speak for pixels) is the size of a version 1 QR code. Each version increases the size by four modules.

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A Paper Printer For QR Code Menus

October 26, 2023 by 24 Comments

Do you miss the days of thumbing through a sticky, laminated booklet to order your food? Sick of restaurants and their frustrating electronic menus? Fear not, for [Guy Dupont] and his QR code menu printer are here to save the day.

Yes, that’s right — it’s a lunchbox-sized printer designed to spit out a paper version of a digital menu. Using a Tiny Code Reader from Useful Sensors, the device can scan a QR code at a restaurant to access its menu. A Seeed Studio XIAO ESP32 takes the link, and then passes it to a remote computer which accesses the menu online and screenshots it. The image is processed with TesseractOCR to extract food items and prices, and the data is then collated into a simple text-only format using ChatGPT. The simplified menu is finally sent to a thermal printer to be spat out on receipt paper for your casual perusal.

[Guy] was inspired to build the project after hating the experience of using QR code menus in restaurants and bars around town. It’s his latest project that solves an everyday problem, it makes a great sequel to his smart jeans that tell you when your fly is down.

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Four images in as many panes. Top left is a fuchsia bottle with a QR code that only shows up on the smartphone screen held above it. Top right image is A person holding a smartphone over a red wristband. The phone displays a QR code on its screen that it sees but is invisible in the visible wavelengths. Bottom left is a closeup of the red wristband in visible light and the bottom right image is the wristband in IR showing the three QR codes embedded in the object.

Fluorescent Filament Makes Object Identification Easier

August 17, 2023 by 14 Comments

QR codes are a handy way to embed information, but they aren’t exactly pretty. New work from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have a new way to produce high contrast QR codes that are invisible. [PDF]

If this sounds familiar, you may remember CSAILs previous project embedding QR codes into 3D prints via IR-transparent filament. This followup to that research increases the detection of the objects by using an IR-fluorescent filament. Another benefit of this new approach is that while the InfraredTags could be any color you wanted as long as it was black, BrightMarkers can be embedded in objects of any color since the important IR component is embedded in traditional filament instead of the other way around.

One of the more interesting applications is privacy-preserving object detection since the computer vision system only “sees” the fluorescent objects. The example given is marking a box of valuables in a home to be detected by interior cameras without recording the movements of the home’s occupants, but the possibilities certainly don’t end there, especially given the other stated application of tactile interfaces for VR or AR systems.

We’re interested to see if the researchers can figure out how to tune the filament to fluoresce in more colors to increase the information density of the codes. Now, go forth and 3D print a snake with snake in a QR code inside!

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It’s Snake, In A QR Code, But Smaller

August 3, 2023 by 15 Comments

We’re not sure that many of you have recognised the need in your life for an x86 machine code program encoded into a QR code, but following on from someone else work [donno2048] has created a super-tiny Snake clone in assembly which comes in at only 85 bytes long. It fits far better in a QR code than the previous effort, but perhaps more useful is a web page demo which runs an in-browser DOS compatibility library. We followed the compilation instructions and got it running on our Manjaro installation, with the result of a somewhat unplayable but recognisable Snake, we’re guessing because it was written for a slower platform. The web version is more usable, and allows us to investigate its operation more thoroughly.

To achieve a working game in so little code is an impressive feat, and since we found different keys responded on machines with different keyboards we’re curious how it does its keyboard input. Also we think it has the Snake bug where turning back on yourself means instant game over. We would be interested to hear the views in the comments of readers who know something about x86 assembly, to help explain these points.