Ok Cred Forums I have a question
Is it possible to create a app for your phone that will use its flash led and camera to create a Li-Fi network?
I mean you could just have to point the phones at each other and be able to easily transmit data. Wouldn't this be possible on any popular modern day smartphone?
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Yes it would, now go out and write the code, shouldn't be too hard.
I know nothing about code :(
What would be the benefit of using this over bluetooth or direct wifi?
Would it be more power efficient? More open in terms of use?
>flash light heatens up
>20mins in burns out
>effectively destroying the camera and with it sensitive components like the speaker grill
>cracks open
>suddently GILGAMESH vs C'thulu
can you not run the led for long periods of time?
>flash the light
won't have fast or accurate timing, good luck doing anything but human speed morse code tier data transfer that way
>camera
also slow as fuck, 120fps maybe at best on some phones
far better using acoustics, there's already software available to do this, but this won't be good for more than a couple hundred baud, if you're in a reasonably quiet area
thankfully, phones already have bluetooth and wifi chips which are far better for this kind of thing
-- speaking of cameras/lights
you're much better off generating/displaying/capturing 2D barcodes
possible? kind of. you can certainly write an app that transmits data this way. it just won't be very fast, because the flash LEDs just aren't built for this kind of thing. they can't turn on and off very fast or with very precise timing. there are also limitations on the camera side.
Ok thanks didn't relize how shitty the hardware was.
they just weren't designed for this
/as a camera/ 120fps is pretty good
and the flashlight is only made to be bright, it doesn't really matter if it takes an a few 10's of milliseconds to turn on or off
I understand
3d*
no, 2D
No, 3d
explain
-- or are you referring to time?
Yes
It's possible but inefficient. Essentially a serial connection. Acoustic is also another option.
This would be a fun project to experiment with but that's the end of its practical application.
I might just go ahead and give it a go myself. Thanks for the project.
no problem user :)
you might be better off using the ambient light sensor instead of the camera for receiving
a lot easier to process, that is assuming android/ios provides access to the raw value without root
Yes. It's just going to be very slow. There are phone apps that do this MorseTalk is an example of such an app. It uses the flash and camera to transmit and receive morse code and is intended for emergency scenarios.
IE communicating with people stuck on buildings after an earthquake.
The range one can get is pretty surprising
There is no problem
A much better way to do it might be to exploit the fact that one has several communication channels. IE screens can transmit different colors and cameras can receive different colors.
So if one could make the phone screen flash a bunch of different colors really fast one might be able to get some decent range as one would just need a bead on the couple of flashing pixels.
Of course flashing a bunch of colors very fast might induce seizures in some people.
As an aside, it would probably be trivial for manufacturers to make phones support low bandwidth(100s of KHz at the very least) lifi through the camera and flash, it's just that no one really uses such things because no one agrees to a standard. Just like NFC
I know some apps that use the the light sensor w/o root
Could you easily buy a led and light sensor that could support a much faster data transfer rate
>screens can transmit different colors and cameras can receive different colors.
you'll get better bandwidth with 2D barcodes
some are even in color for higher density
>manufacturers to make phones support low bandwidth(100s of KHz at the very least) lifi through the camera and flash
something official would use something more suitable than the camera, both for power consumption and cpu usage reasons, and because cameras that so even 10,000fps (still pretty shit for this kind of thing) are expensive as shit
they'd use something like a photoresistor or whatever, something that responds quickly to changes in light in an analog fashion that can be sampled very quickly
the camera flash is fine (LED), just need to be hooked up to a chip that that is suited for this job
>I know some apps that use the the light sensor w/o root
but do they get the raw value? or just some abstract "dark room/light room/outdoors" kind of value
I don't know
didn't japphones used to do something like that with red light or some shit?
infrared
>2D barcodes
You don't happen to have that data-to-QR-code-webm program a Cred Forums user made a while back do you?
that was me
2d barcodes have better bandwidth but less range.
>>camera
You would use all of the pixels of the camera as a light sensor. One doesn't need to process or capture the frames, which is what makes high speed cameras expensive, just a way to sum up all pixel values.
Cameras have a nice feature of having optics already in place, although I suppose one could hide a big o strip of pin diode on the screen boundaries.
I'll make the logo
>Can't shitpost in darkness
>Can't shitpost from under a blanket
>Can't shitpost without neighbors noticing
>Have to keep lights on all day even if sunlight was enough
Doa
should be noted, while the OP in that thread wanted to use QR's, mine (the style that someone turned into some desktop program) didn't use QR codes, and isn't suitable for picking up with a camera
Ok at what rate do you think the LED could transmit data
What rate could the camera pic up the data?
Anyone got the desktop program still?
But if you keep your blinds close your neighbors can't steal your Li-Fi
Op here I'm going to bed, but I'll bookmark this thread to see if anything happens
Have a good night anons
use infrared... like we used to
this literally used to be the way to transfer stuff wirelessly to phones and other stuff before wifi took over
en.wikipedia.org
i don't remember what it was called, i wasn't interested in actually using it