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c/technology · by new_otters_raft@piefed.ca · 25d

Decimen Lets You Send Files Through Light, Not a Network

https://linuxiac.com/decimen-lets-you-send-files-through-light-not-a-network/

I'm not sure when I'd use this, but its a neat concept

Decimen is an open-source web app that moves files between devices through an animated QR stream, requiring no direct network connection, pairing, account, or native app.

102 points · 30 comments · view on lemmy.world

30 Comments

deranger@sh.itjust.works · 34 pts · 24d (8 replies)

Wi-Fi is already using light to transmit digital data. Shit, radio was transmitting data using binary with Morse code in 1895, also using light waves. Radio requires no direct connection, pairing, account, or apps.

Uli@sopuli.xyz · 30 pts · 24d

I don't trust invisible light. If that light had nothing to hide, it would be on the visible spectrum.

new_otters_raft@piefed.ca · 7 pts · 24d (3 replies)

I wouldn't use this day to day, but what I found cool was:

  • it doesn't require cables or any additional equipment (including routers, cell towers)
  • it can't be detected by anything, assuming you toss a blanket over the transfer

The downside is that if you wanted to get it truly offline, you would need to have the an app installed on both devices ahead of time, if I understood it correctly. (Edit: bolded bits are new)

It did lead to some fun discussion in this thread :)

ExcessShiv@lemmy.dbzer0.com · 6 pts · 24d (2 replies)

The downside is that you need to have the app installed on both devices ahead of time, if I understood it correctly.

You did not. It's a web application, it even says so in the snippet you used for the post. It runs directly in the browser, no need to install anything.

AnUnusualRelic@lemmy.world · 4 pts · 24d

So you need to be connected in order to grab the application. Or you need a local cache (similar to installing the software).

new_otters_raft@piefed.ca · 0 pts · 24d

That's my bad for writing it poorly. I meant to say that about the premise of not needing internet, since someone who has internet on both devices might have better ways to transfer the files.

Someone would need to plan ahead and install the PWA (or some compatible tool) in order for this to work

tias@discuss.tchncs.de · 6 pts · 24d

But it's light arranged in a specific pattern!

frongt@lemmy.zip · 0 pts · 24d (1 reply)

Radio and light are different parts of the EM spectrum

deranger@sh.itjust.works · 7 pts · 24d

No, radio is light. They’re all light waves from gamma rays to radio waves. Not visible light, but light nevertheless.

shortwavesurfer@lemmy.zip · 17 pts · 25d (4 replies)

There's this science fiction book, and I'm blanking on the name of it right off hand, but there's a harvester that attached itself to Ceres, the asteroid, and made octagonal solar shades to freeze the Earth.

The reason I bring it up is because if they detected radio signals too close to them they would fold in on themselves and direct a high energy beam of sunlight towards the target and vaporize them and so the ships would communicate with patches that were basically QR codes on the outside of their hull and the other ship would take pictures and be able to transfer data that way.

I want to say they were using the equivalent of high refresh rate E-Ink screens.

Flower@sh.itjust.works · 8 pts · 24d

Ceres, the asteroid

That's dwarf planet now.

KairuByte@lemmy.dbzer0.com · 5 pts · 24d (1 reply)

My brain is unreasonably stuck on how solar shades on an asteroid could freeze the earth.

shortwavesurfer@lemmy.zip · 7 pts · 24d

They were made on the asteroid and then flew themselves to a spot between the Sun and the Earth.

They were basically smart machines.

morriscox@lemmy.world · 1 pts · 22d

https://whatisthatbook.com/ might be able to help though it didn't work for me.

artwork@lemmy.world · 11 pts · 25d (4 replies)

A relatively similar tech, though no actual graphics are involved like QR-code images, and hence may be more energy efficient, is of course - Infrared Data Association (IrDA).

Some may still recall the Symbian, music/picture/game files transferred slowly but awesomely between friends/partners watching devices carefully aligned on windowsills, tables...

IrDA is a wireless standard designed for data transmission using infrared (IR). Infrared ports for this purpose have been implemented in portable electronic devices such as mobile telephones, laptops, cameras, printers, and medical devices.

The main characteristics of this kind of wireless optical communication are short-range, physically secure and bidirectional data transfer, at serial cable speeds, with a line-of-sight using point-and-shoot principles. IrDA has been made dormant by newer improved technologies like Bluetooth.

Source: https://en.wikipedia.org/wiki/IrDA

jubilationtcornpone@sh.itjust.works · 4 pts · 24d (1 reply)

I remember when I learned how to transfer files from my IBM Thinkpad running Windows 98 to my Compaq iPaq pocket pc over the built in IR transmitters. It worked, albeit very slowly.

cmnybo@discuss.tchncs.de · 4 pts · 24d

The modern version is called Li-Fi. It's capable of multi gigabit speeds. There doesn't seem to be much that actually uses it though.

brsrklf@jlai.lu · 4 pts · 24d

There's an app, Petit Computer/SmileBasic, available on Nintendo consoles since the DSi and Wii (then had 3DS, wii U and switch version). It's a programming language that has a lot of features using the target console's input/output capabilities (touch screen, 3D, gyroscopes, etc).

On 3DS there was a feature to share files (code, image...) through the app's server, but some wanted to be able to share their stuff in other ways, so they didn't depend on the app server or so they could share locally with a PC for example.

Someone made a modem kind of program with it to transform the file into a sound sequence, emit it, receive it on another device through mic and retransform it to file. Max transfer rate 92 bytes per second with error checking.

thehatfox@lemmy.world · 4 pts · 24d

I remember IrDA, I also remember it being frustratingly slow and unreliable.

Visible light data transfer isn’t new either. The Timex Datalink watches were using flashing coloured patterns on a PC monitor to send data to them in the 90s.

Cocodapuf@lemmy.world · 8 pts · 24d (1 reply)

Decimen Lets You Send Files Through Light, Not a Network

I mean, that's a new interface type, but it is a network.

If two machines are exchanging data, that's the definition of a network.

LodeMike@lemmy.today · 6 pts · 24d

Network? I sure hope it would.

Sasha@lemmy.blahaj.zone · 8 pts · 24d (1 reply)

there's a bunch of open source (and abandoned) repos on GitHub that do this using fountain codes, fascinating stuff but not all that good, they have huge limits on the transfer rate. I recalling seeing some that use JAB codes which cram more data into each code using colours, not sure how much better they'd be than this though.

Sasha@lemmy.blahaj.zone · 7 pts · 24d

I should probably mention that a fountain code isn't a barcode like a QR or JAB code, they're a way to do error correction which can be applied to sequences of barcodes

GreenKnight23@lemmy.world · 6 pts · 24d

that's nice and all but there's another project that did it first and did it better.

https://github.com/sz3/cfc

CFC uses cimbar codes which are multicolored codes that can transfer up to 106 kb/s

eleijeep@piefed.social · 5 pts · 24d

Looks vibe-coded.

RIotingPacifist@lemmy.world · 5 pts · 24d (1 reply)

Stream QR code seems like a very inefficient way to send data.

hummingbird@lemmy.world · 3 pts · 24d

This is a very quick and reliable way to transfer when there is no direct device connection. Of cause you would use than instead when available. But in some situations there simply isn't any.

a_non_monotonic_function@lemmy.world · 4 pts · 24d

Given the horrible speeds I'm not certain why.

artyom@piefed.social · 1 pts · 24d

Brilliant

Malyca@lemmy.zip · 0 pts · 24d

Really cool concept