
A Near-Ultrasound (NUS) Data Link - sohkamyung
https://www.bunniestudios.com/blog/?p=5847
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gioscarab
In almost ten years of research and experiments I have developed a data-link
that uses a single LED for both reception and transmission:
[https://github.com/gioblu/PJON/tree/master/src/strategies/An...](https://github.com/gioblu/PJON/tree/master/src/strategies/AnalogSampling)

2 devices with a single LED on each can establish half-duplex wireless
communication based on light impulses. I think that is a much more efficient
and cheap way to transport configuration settings or even an entire program.

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tj800x
I suppose the LED flash on the phone could be modulated for this. Eliminating
the configurator-hardware is important for this kind of application.

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ermir
I remember seeing an app once that was used in stadiums and other public
venues that could be used to create a distributed and coordinated lightshow
with the audience smartphones. How it worked is that the audience would
activate an app, put their phones up in the air, and a loudspeaker in the
stadium would emit ultrasonics that the phones would pick up. The phones would
then turn their screens on or off, and by using different frequencies, you
could switch up their colors or selectively turn on only a couple of phones.

Ultrasonics are a really cool and easy way to have short range transmission of
data, or even broadcasting with a loudspeaker. The data rate may be low, but
it's perfectly fine for stuff like toggles, or transmission of commands.

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akadruid1
There are hearing aids which use ultrasonics to send settings from a
smartphone app. I thought that was a pretty neat solution given the device has
strict constraints on size, weight and battery life. Traditional hearing aids
can be fiddly to adjust even for users with good vision and fine motor skills.

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tj800x
The use of this for setting configuration options is absolutely brilliant.
I've been looking at cheap ways of doing this for years. That you would
publish this patent-free is fantastic. Thanks!

