It's been a while...

[Carl]

...since anyone has posted progress on a SSS project. There were once several active designs going on, and it looked like good progress being made, then everyone seemed to stall.

I'd like to get a reading on where folks are at with their projects. How far did you get? What is keeping you from proceeding forward? Are you interested in continuing your project, or have you moved on to something else?

I get emails from time to time from people wanting to make a SSS, so interest is still there. Let's hear from everyone!

- Carl

[Jonas]

Re: It's been a while...

Hi Carl

I´ve followed the forum for some time but as you say, everyone seems to have disappear. I am struggling with my sss but having problems finding people who knows enough about electronics, I have to learn about it myself. But I´m making progress,altough it´s slow. There are a few problems ahead but I will take care of them as I get there.

Hopefully people will come back!

Jonas

[Jan]

Re: It's been a while...

Hi Carl,

I have put this program into hold for a while because I had real problems getting the parts I wanted.

For some reason they do not sell transducer cristals here and due to a stupid mistake I made I blew the ones I got from USA.
I also have problems getting the AD600 chip... though last week I found a company that has them but.... I can only order there when I am a company myself.... :-((

So I switched to magnetometer design.
That goes on very well.
I am using the Speake sensors you used in your design.
Realy nice sensors.
Two weeks ago I switched the Mag on for the first time.... and it works.
When I move a small screwdriver I see the graph on my computer reacting quiet nicely.
The srewdriver has only a very weak magnetic field, but the sensors detect it.
Even without having first adjusted the sensors

But my Optical fiber design is a big dissapointment.
It works fine for low frequency but at a bit higher frequency it is useless.
At 9600 bps it just garbles the data..

Again I have problems getting parts.
I wanted to use the TODX294 but cannot get that chip here.
I even emailed Toshiba
The send me an addres here in Holland where I could order them ... so they said
I phoned this company, but I had to order at least 15 modules at $30 a piece... bit to expensive.
So I tried another module.... with above described result.
Perhaps you have an idea...
I am using a twin 1.2mm plasic fiber optic cable 100 meters long.
One strand transmits the other receives data at maximum of 19.200 bps.

For the SSS I need high speed, so it is useless to build it when I cannot get the data into my PC.

This all is very frustrating.
But, it looks like I get the Magnetometer working before the diving season opens. :-)

Jan.

[Carl]

Re: It's been a while...

Jan,

Can you use an AD603 instead of a 600? I have a few of these. Since I work for Analog Devices I may be able to get some 600's if that's what you need.

I think everyone else is having problems getting transducers as well.

- Carl

[Carl]

Re: It's been a while...

I think there's enough electronics knowledge amongst the people who were working on the SSS projects, just didn't have good sources for transducers.

- Carl

[Jan]

Re: It's been a while...

Carl,

The AD603 is a single amp (I believe)
I need the AD600 or AD602 (Better signal to noise ratio) because it is 2 amplifiers in one package

How much would it cost if you could get me a AD600 and a AD602 ?

I would like to continue SSS again after I finished Magnetometer.

I got some transducers (the crystals themselves) via forum, but I cannot order them myself from here as the company does not ship overseas.
So for people living in USA it schould not be a problem ordering them.

Best regards Jan.

[Charles]

Re: It's been a while...

Hi Jan, I am placing a few orders tomorrow and searched to see if Digikey or Newark carried a "TODX294" and I found no reference to it. Then I searched several websites used to help locate parts sources and absolutely nothing turned up. Is this part number correct? You had no reference in your post as to what it is or what it does. Can you check it before I place my orders tomorrow?
Thanks,
Charles

PS-I'm building a boat towed metal detector and an underwater altimeter. Then I'm going to work on a magnetometer and a few other things. Then I plan to jump on the SSS project. I've been putting it last because I know its going to be time consuming and costly.

[Charles]

Re: It's been a while...

Well, I found your TODX294 on the Toshiba website but I can't find anyone that sells it. Sorry,
Charles

[Jan]

Re: It's been a while...

Charles,

Sorry for the late response... somehow did not see your replies.. getting old I suppose..

I have been looking for other parts to make the Fiber Optic interface.
I really get pi.... off with not getting the parts I want.
Either I have to order them in large quantities or I must be a company myself...

So I think I drop the fiber optic and go for twisted pair.
I put the loss of $100 for the fiber optic down as "learning" money... hehe.

Twisted pair cable should do 1200 meters without a problem... accoording to the manuals.

I only need to get this cable working so I can test my magnetometer
With a short cable it works very nice.
It is not so hightech like a professional one but I hope it will do the job of finding wrecks at 20-40 meters.

Jan

[Carl]

Re: It's been a while...

Jan,

I think I've come up with the AD600. Apparently the 602 is not available in the DIP package which I assumed you would want. Email me a shipping address and I will get a couple of them in the mail as soon as I get them.

- Carl

[Charles]

Re: It's been a while...

Hi Jan,
Yes, I thought about it last night and was wondering why you were going to the trouble and expense of fiber optic for only 100meters when you could use good old fashioned wire for that, especially at only 19.2KB. I would think you would get very high speeds with fiber. My underwater altimeter is sending up depth information serially on 100meters of cable. Of course its only 4800 baud though. Are you using RS-485 for the electrical spec? Curious what you are doing in that regard. I'll go ahead and place my orders now since you have no other requests
Thanks,
Charles

[Jan]

Re: It's been a while...

Charles,

I am going to use RS-422 because I only need "point-point".
Phoned the shop today and they can deliver the parts I need.
I was using the fiber optic because my boat has an outboard engine and those produce much eletrical noise

But accoording to the datasheets I got on the RS-422 & RS-485 the noise should not be a problem now...

When I have time I will buy the cable and parts tomorrow.
Will have to redesign PCB (again..)

Then the only thing left to do is to mount the watertight connector to the fish and start testing..

Best regards, Jan

[Jan]

Re: It's been a while...

Charles,

I was wondering, what does your underwater altimeter do exactly ?
Is it a kind of depthgauge ?
Or does it tell you how high you are off the ground... (that would be a handy thing for a towed rig.... specialy if it would also detect obstructions in front of the rig)

Just a bit curious.... well a bit more than just a bit.. hehe


Jan

[Jan]

Re: It's been a while...

Carl,

Sounds great !

Sent you an email with my adres.

Thank you very much for the effort you took, I am really pleased.

Best regards, Jan

[Charles]

Re: It's been a while...

Hi Jan,
The underwater altimeter is going to tell the distance from the seafloor to the fish so I can keep the towfish as close to the bottom as I can without hitting it. I plan to have the ability to program an alarm level in it so if the fish falls to the alarm depth, it will buzz and light an LED. It will not tell you of obstructions in front, it is basically a depth finder like a boat would have using a piezo transducer showing depth in meters or feet (selectable). This will be displayed on the top line of a 16X2 LCD and the bottom line will show your alarm set point. I have completed the schematic, PCB, a case panel, and ordered the parts today. The only thing left is to finish the PIC code which is about half done.

Can you tell me about the water proof connector you are using? I am going to have a need for one soon and would like to know what you have decided to use.

RS-485 should work fine since its differential and should be pretty immune to your engine noise I would think. I plan to use that if I can get to building an ROV. I am building the easy stuff first and then I'll move to the harder stuff like side scan and an ROV. I have been studying up on ROVs and I think that will be easier of the 2 for me. The hard part for me is getting stuff that works in water. I'm not a mechanical engineer and am learning as I go. If you want anymore info on the underwater altimeter I want to take it off line as I'm not ready to give up my secrets yet Some of the stuff I'm using is only available OEM, so you have to have a company name to get them to sell it to you.
Thanks,
Charles