Subject:
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Re: Sonar Sensors
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Sun, 21 Feb 1999 18:39:17 GMT
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Original-From:
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Will Bain <WILLBAIN@CS.UMT.EDUnomorespam>
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Viewed:
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1069 times
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Ian Hojnicki wrote:
> Ok... both of my sonars are now fully functional and clicking like they
> should... I took the test prgram from the website and changed some of
> the values to make it use D3 for the other sensor... Here is my problem
> though... When I output the values from the sensors to the LCD display,
> they appear to be random numbers... Any clues as to what is wrong???
> Any suggestions would be appreciated...
I don't know much about electronics, but here are a few hardware
questions that others have asked me:
Can you verify that each sonar works ok all by itself?
Are you using two separate sonar module boards, one for each transducer,
or are you running both transducers off the same module through a
multiplexor? I've been trying to do the former. If you've done the
latter, then some of the other questions may not make sense.
Did you solder the capacitors into position C7 on the Polaroid sonar
module boards? They're necessary for the correct operation of the
modules.
Are you using 6 power diodes to drop the voltage down from 9.6 V at the
HB to about 6 V at the sonar module boards? That's the best way to get
power to the modules. You can use a separate battery for the sonar, but
make sure it has adequate surge current capacity (the HB power does).
Do you have two echo lines connected to the same TIC port on the HB? I
tried that and it doesn't work for me at all. I was warned that there
might be signal contention with two echos on the same port, and it
appears that that's the case. I haven't tried the switching diodes yet
to see if that fixes it.
Are you triggering two pings at almost the same time? If so, there may
not be enough surge current to supply both modules at the same time, or
the reverberations from one transducer could be affecting the other.
Make sure that you pause between firing one sonar and firing the next.
Remember, even after the first echo returns to the transducer, there
could still be more echos bouncing around the room for a few
milliseconds.
I also have written code to use two sonar modules with the HB. Perhaps
if you wouldn't mind sending me your code, I could look over it and help
figure out whether it's a software problem. I know a little more about
programming than I do about electronics.
Sincerely,
--Will
, ,
__@_/ \_@__ |/
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)\ ) ( \ (\/\\,
~~~~~~~~~ ' ` ~~~~~~~~~~~ ` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Wendy Parson, Conscience: the inner voice which warns us
Will Bain, that someone may be looking.
& Tatoosh --H. L. Mencken
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Message is in Reply To:
 | | Sonar Sensors
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| Ok... both of my sonars are now fully functional and clicking like they should... I took the test prgram from the website and changed some of the values to make it use D3 for the other sensor... Here is my problem though... When I output the values (...) (26 years ago, 20-Feb-99, to lugnet.robotics.handyboard)
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