Hhhhhh I am elecrical engineer and I didn’t know this too.

Fun fact you can also light a solar panel like an LED, it's definitely not as bright.

@@TechTroppy many solar panels will only emit in the infrared when you put a voltage across it.

I find that normal multimeters can't read the voltage the led produces, as they have a 1M ohm of leakage. That Arduino uno analog in pins can read the voltage very well! it's leakage is 40-60 M Ohms

@@username4835 A phone camera will pick up IR light, so this should be easy to test.

yup, I did it and it's also quite cool to see. It lights up in stripes and looks like broken glass (at least the cheap ones)

@@simonecastello991 that's when they're actually cracked, the sections that are broken don't work as well but the entire thing still does work a bit

@@__lasevix_ nice to know. I mean, it was from one of those old toys. I don't think that they ever cared about efficiency

@@r.faj.5636 that's rad

Don't forget about piezoelectric effect!

I screenshot your comment. That is just poetry. Great

Remove the DC there every motor Is a generator even induction motors

I wanna go to your kind of parties lol

​@@CullenCraftWhoaaa, put the bottle down.

I'm literally Einstein now.

There were no LEDs back in the 70s

@@alejandroperez5368 first production in '62. Yeah, there were LEDs in the 70s.

Hacking! CIA knows all about it.

LEDception

Depends on how much light you put into it and the responsivity of the LED when used as a photodiode. A high power LED isn't likely to be any better than a small one, and you definitely want to avoid any LEDs that use phosphors e.g. white.

My experiments with an orange LED show nanoAmps... Not even registerable on a multimeter, and certainly not directly connectable to a uC pin. Though, now that I think of it, it could be a phosphor-coated blue LED... hmm.

Yes, though the current transfer ratio won't be particularly good.

Infrared light from a solar panel. This is actually used to check panels for damage, it will clearly show up cracks etc when viewed with an infrared camera.

I have seen someone make a gesture sensor of sorts. They made an 8x8 LED matrix and they turn off one LED at a time and measure the light reflected by the hand close to it.

Figuring out the software would be the challenging part, I'd say.

I once used a 1N4148 as LED. Wondering why it was yellow and not green - the color LED I had bought. Then realized it was the wrong diode and that I sent a huge amount of current through it.

There is no lens to focus the light, so every LED would see a fraction of the same light.

​@@perwestermark8920Ever heard of DSP? Convolution matrices can do quite a bit! Heh. Chiva: It's interesting the fear is "data hogging corporations"... Makes things like this seem far less malicious than folk of my generation were warned of. But, yeah, think about it... do you really think the almighty dollar, times two hundred, could possibly manufacture, in any country, two perfectly-parallel sheets of glass, separated by an exact number of microns throughout its entire 52in-diagonal surface? They'd pay us to buy these things, if it wouldn't make us suspicious.