On Sat, 2 Feb 2002, Donovan Parks wrote:

> Hello Dale,
>
> Expense - a pressure sensor is cheaper than a sonar unit.  Besides that, I
> had a pressure sensor already.

OK, I can see that would be a couple of excellent reasons.  Those are very
often the exact reasons I have for things I do!  8-)

> Have you tried using a sonar sensor to measure depth?  Do you receive
> a strong signal from the reflection off the waters surface?

No, I haven't.  I have done quite a bit of work over the past year with
sonar rangefinding, and the units I've been using are pretty sensitive --
I would be very surprised if they wouldn't see the surface.  Of course if
you went much below four or five fathoms the ones I have been using
probably wouldn't do much good, they seem to be reliable only out to about
30-something feet.

Dale

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.