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Subject: 
Re: Homebrew sensors?
Newsgroups: 
lugnet.robotics
Date: 
Sat, 14 Nov 1998 00:11:40 GMT
Original-From: 
Daniel Miller <danielmi@expert.%NoSpam%cc.purdue.edu>
Viewed: 
2327 times
  
On Fri, 13 Nov 1998, Michael Gasperi wrote:

There is a single channel sound sensor on my web page:
http://ourworld.compuserve.com/homepages/Michael_Gasperi/lego.htm
It was really designed for picking up loud noises like claps.  What you want
would require two mics and a circuit that would take the difference between
the sound levels.  Better yet it should have a very narrow bandpass filter so
that only sound a particular frequency would be heard.  The output would look
something like Light values: 50 for equal sounds at both mics, 0 for mostly
left mic, and 100 for mostly right mic.  The same kind of scheme could be done
for temperature to make a heat seeking robot.

I was thinking of something that sensed amplitude, not frequency.  (Like
the light sensor, which sees brightness, not color.)  Of course, whatever
you want for yourself is best. :)

I know the logic of taking two sensors and differentiating to find
direction.  I was looking for a way to do it with only one.  I don't know
if what I proposed (do a 360 scan, then return to loudest) can be done
with the Spirit library; I think it would need arrays.  A better thing
would be to compare the current amplitude to the last.  However, the robot
would then go to the first sound it "saw" rather than the loudest.

I was cruising TRU looking for deals this afternoon and saw a dish-type
directional mike.  It was rather garish, I suppose so Junior's parents can
tell when he's listening in.  But I think it would look pretty nifty on a
'bot.

Daniel "Dan'l" Miller                Senior, School of Aeronautics and
danielmi@expert.cc.purdue.edu        Astronautics, Purdue, Indiana
danielmi@cartoon.ecn.purdue.edu



Message has 1 Reply:
  Re: Homebrew sensors?
 
(...) So's Michael - he's proposing a notch filter so you get the amplitude at a particular frequency, which may be better for a seeking application. Cheers, Ben. (26 years ago, 14-Nov-98, to lugnet.robotics)

Message is in Reply To:
  Re: Homebrew sensors?
 
There is a single channel sound sensor on my web page: (URL) was really designed for picking up loud noises like claps. What you want would require two mics and a circuit that would take the difference between the sound levels. Better yet it should (...) (26 years ago, 13-Nov-98, to lugnet.robotics)

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