Depth Finder

[VICI]

I'm working on a boat which will be tossed into a lake and allowed to float free.
Every couple hours or so it will wake up and take a reading of dissolved oxygen content, air and water temperature, pH, it's position, the lake depth and take a picture. This will all be sent back to base station and uploaded onto a website.
Cute, right?
So, my project right now is the depth finder. I've been looking at fishfinders and how they work and I think that's probably the best way to go - run an electronic input into a transducer and send out a fairly low-frequency sound wave since the lake will probably be deep. (Erie/Ontario).
However, I've been looking for such an ambitious soul who has posted such a schematic but no such luck. I'm a little sketchy on how to make a reciever that will take it the returning sound waves. Can anyone lend me their Genius?
Thank you so much!

 

[jrz126]

I have some experience with an untrasonic range finder that I hacked from an old camera. I bet it wouldnt be difficult to hack the fishfinder and use the circuitry that drives the transducer. That might be a pretty simple solution.

Where abouts are you at? Lake Erie is right in my back yard...

 

[VICI]

hmm. The problem is then actually having to acquire a fishfinder. I was really hoping to avoid that.
I'm working with the Unversity at Buffalo - it's our research project.

PS - love the photo. I have it in rambo kitty

https://images.google.com/imgres?im...firefox-a&rls=org.mozilla:en-US:official&sa=G

 

[Nigel Goodwin]

hmm. The problem is then actually having to acquire a fishfinder. I was really hoping to avoid that.
I'm working with the Unversity at Buffalo - it's our research project.

I think it would be FAR easier to acquire a fishfinder than to make one, a simple google finds loads for sale - have a look here **broken link removed** for just one example amongst many. Many sites list depth finders as well, which may be even easier - but basically the same thing.

 

[dknguyen]

Here is an underwater sonar transducer...you will need to build the drive/receive and timing circuitry yourself.

https://www.hobbyengineering.com/SectionS.html

Seventh item from the top. Probably doesn't have enough power for your application and it's frequency is probably too high to travel the distance you want, and I don't know if you just want depth or an "depth image" of the lake bottom...in any of these cases fishfinder is the only way to go...for comparison sakes about why you should just get a fishfinder. You aren't going to easily get such a low frequency underwater sonar anywhere else with imaging.

 

[Klaus]

What worries me about this idea is that you are creating a navigational hazard on the lake. Did you check on the legalities of abandoning a vessel? You could be up for substantial damage claims if somebody runs into it at night.
Also, the wind will sooner than later just deposit your boat on the shore somewhere, I hope you have radio tracking equipment, that lake is on the big side to find small unmanned boats.
As Nigel said, buy a depth sounder, far too much involved to build one that works reliably.
Klaus

I'm working on a boat which will be tossed into a lake and allowed to float free.
Every couple hours or so it will wake up and take a reading of dissolved oxygen content, air and water temperature, pH, it's position, the lake depth and take a picture. This will all be sent back to base station and uploaded onto a website.
Cute, right?
So, my project right now is the depth finder. I've been looking at fishfinders and how they work and I think that's probably the best way to go - run an electronic input into a transducer and send out a fairly low-frequency sound wave since the lake will probably be deep. (Erie/Ontario).
However, I've been looking for such an ambitious soul who has posted such a schematic but no such luck. I'm a little sketchy on how to make a reciever that will take it the returning sound waves. Can anyone lend me their Genius?
Thank you so much!

 

[VICI]

Don't worry - this is more for environmentmal studies in park lakes w/o motorboats and the like (ie Algonquin but no one knows where that is lol), or following rivers. But obviously size, weight and power consumption are major issues.
Is it possible to just get the fishfinder transducer and not all that packaging screens and such nonsense?
Anyway, thank you for all your help! I really appreciate your opinions and your concerns. ^_^.\/.

 

[dknguyen]

Not sure...unless you can find "fish finder repair" parts. Or just get the lowest feature fish finder possible. A refurbised model maybe (if they exist for fishfidnders). I don't fish so I don't know!

 

[Roff]

Don't worry - this is more for environmentmal studies in park lakes w/o motorboats and the like (ie Algonquin but no one knows where that is lol), or following rivers. But obviously size, weight and power consumption are major issues.
Is it possible to just get the fishfinder transducer and not all that packaging screens and such nonsense?
Anyway, thank you for all your help! I really appreciate your opinions and your concerns. ^_^.\/.

Did you Google "fishfinder transducer"? The 3rd hit was **broken link removed**, which lists sources for transducers at the bottom of the page. I didn't check them out carefully, but they looked promising.

 

[Nigel Goodwin]

A point that's not been suggested yet, is to go and visit places that sell fish finders, presumably boat chandlers etc.

They may be able to make suggestions, and may even have a damaged one you could buy cheap?.

 

[dknguyen]

Assuming if it's damaged you won't be able to fire it up to test it so make sure the right part of it is damaged

 

[VICI]

Hey all! Thanks a ton for the help. I think I found my device - a "Smart CTD" - it measures D.O., temp, conductivity, pH, and (fanfare please) depth! Anyone have any experience with it? I'm still looking into the data sheets, I would presume I just need different formulas to put voltage/frequency (w/e) into whatever data I want. Nifty huh? Here's hoping. Again, Thank You!!!