Re: Acoustic Modem For A Hobby AUV


<pbdelete@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:44ad51aa$0$486$cc7c7865@xxxxxxxxxxxxxxx
I'm building an AUV for hobby use, however I'm having trouble whe it
comes
to communications. So far I've considered sending DTMF tones through 2, 2
way radios, and encoding sets of numbers on R/C equipment but neither will
travel/penetrate far enough (<3m).

It needs to be a duplex system capable of transmitting 32 on/off comands
and
8 values (0-255) through about 100m of water.

So far I've found lots acoutic modems except they are more for industrial
use and so are rather high-spec compared to what I need.

You proberbly know that atomic subs use very low frequency less than 3 kHz
asfair to send to a submarine. Maybe slightly higher frequencies would be
ok
in this case.

As for acoustic, maybe you could either try to use a modem + waterproofed
speaker/mic. If that won't work you might have to implement your own
algorithm.


And I guess I'd then have to apply some form of filter to get rid of echoes
etc?

Michael


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