Ping - How Can I Measure Water Depth
I am new to this forum. Have completed the What is a Microcontroller? program and can make the Ping measure distance in air. I have a need to measure about 3.5 feet of water depth with in a few inches repeatability. Does any one know how I can do this with the Basic Stamp HomeWork Board rev E or a different board? When the tubes from the Ping touch the water it does the same thing as blocking it with your finger. The Ping frequencies seem to be in the Sonar range.
I would be happy to try to hack a low cost fish finder but for some reason, think that would be a much bigger job than measuring distance in air with the Ping.
Thanks in advance for the support.
-Mark
I would be happy to try to hack a low cost fish finder but for some reason, think that would be a much bigger job than measuring distance in air with the Ping.
Thanks in advance for the support.
-Mark
Comments
Welcome to the forums,
Maybe have a look at this:
http://forums.parallax.com/showthread.php?117483-Measuring-pond-water-depth-from-the-surface
If that's all you need to do, then why not rig up some sort of float switch?
Also, as ElectricAye said why not just a float switch, trigger (float with micro) or resistance type (like a gas tank sensor) ?
Let me know if this is too far out in left field. :-)
Thanks!
The Parallax product: VTI SCP1000 should work fine, sensor mounting could be a small airtight box, with sensor in sealed plastic bag (read diaphram)
in box and air hose connected to box.
You probably can't get resolution of a few inches with an underwater sonar pinger like that. Pond bottoms are sometimes so mucky that it's not clear where the bottom really exists within an inch or so. Erco's suggestion sounds reasonable, though.
Using something like the Motorolla MPX2010 case type 344C with the two plug style connectors will allow yo to directly connect to the sensor with the tube without mucking around trying to build some kind of airtight box (any leak will cause a drop in pressure and lead to a misread of the depth). Have a look at the following data sheet a an example;
http://www.jaycar.com.au/products_uploaded/MPX2010DP.pdf
Rather than just doing things from scratch have a look at the following example. The circuit is reasonably simple using an LM324 quad differential op amp. http://www.practicalarduino.com/projects/water-tank-depth-sensor
http://www.practicalarduino.com/schematics/water-tank-depth-sensor-schematic.pdf
I was going to do this but bought some absolute pressure sensors on sale rather than differential pressure sensors, so beware of what you buy if you decide to take this route.