2000xlt
Flashlight Enthusiast
- Joined
- Dec 16, 2004
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- 1,302
smart leds can be wifi hot spots
- Thread starter 2000xlt
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Steve K
Flashlight Enthusiast
Are white leds suitable for high frequency modulation? I've wondered if the phosphors would slow down the changes in light output.
I've worked with modulating IR lasers at about a 8MHz rate. Pretty neat and fun stuff. I keep meaning to build a little modulated laser or led for home, just to send music from room to room.
Steve K.
I've worked with modulating IR lasers at about a 8MHz rate. Pretty neat and fun stuff. I keep meaning to build a little modulated laser or led for home, just to send music from room to room.
Steve K.
gadget_lover
Flashaholic
I agree. the decay rate of the phoshor glow wil limit the throughput.
Daniel
Daniel
UncleFester
Flashaholic*,
Hmm.. doesn't wifi have data going both directions? I guess your 'puter would need a spotlight to point at the LedFi source....???????
gadget_lover
Flashaholic
Like many "novel" ideas, this one is:
1) an old idea. First saw it done with infrared in the 1980s.
2) subject to several drawbacks, such as collisions, one way data, etc.
3) made to sound exciting, even though it's not.
Remember a few years back when "they" were proposing that everything in your house should be "smart" and networked? My closet still does not need to ask my shirts "how many are left". I can look and get that info for free.
Daniel
1) an old idea. First saw it done with infrared in the 1980s.
2) subject to several drawbacks, such as collisions, one way data, etc.
3) made to sound exciting, even though it's not.
Remember a few years back when "they" were proposing that everything in your house should be "smart" and networked? My closet still does not need to ask my shirts "how many are left". I can look and get that info for free.
Daniel
Steve K
Flashlight Enthusiast
I think the idea is certainly valid, and infra-red is already a somewhat standard way to transmit data (I think there's some standard called IRDA?).
There's no question that an IR datalink can be much more secure than RF.... that was the point of the laser communications program I worked on. Of course, a wired connection is pretty secure too, so I'm not sure that IR is any better when sitting in a coffee shop.
Still, it's a fun idea, and the principle dates back to at least the Cold War. I saw something about people communicating between East and West Berlin via modulated IR incandescent bulbs! They used optics to get the beam nice and tight, and could send audio back and forth across the wall. Very neat! Makes me wonder if the bulbs were IR, or if filters were used to block the visible light?
Steve K.
There's no question that an IR datalink can be much more secure than RF.... that was the point of the laser communications program I worked on. Of course, a wired connection is pretty secure too, so I'm not sure that IR is any better when sitting in a coffee shop.
Still, it's a fun idea, and the principle dates back to at least the Cold War. I saw something about people communicating between East and West Berlin via modulated IR incandescent bulbs! They used optics to get the beam nice and tight, and could send audio back and forth across the wall. Very neat! Makes me wonder if the bulbs were IR, or if filters were used to block the visible light?
Steve K.
