Re: measuring depth

[SJSVOB@aol.com]

<< My question is this:  I need a device
 that measures the depth that my sub is operating at and then transmits the
 information to a display on the surface.  This isn't a remote controled
 boat...it is "hard wired". >>

As an electrical engineer and computer scientist I would solve the problem by
giving the ROVs some intelligence via a Motorola HC11 microcontroller.  One
could communicate with the ROV's mircrocontroller via simple serial commands.
For example "Q" for Query would automatically feed back to you a list of all
your sensor outputs, "DEPTH: 300FT, HEADING: 130DEG, BATTERY: 50%" etc.  Or
you could send a command like, "B" for Blow Ballast or "I,J,K or M" for
Forward, Left, Right, Reverse.  Essentially you could control your sub via a
terminal emulator like Procom Plus.  But that is awkward so I would not stop
there.  I would develop an application which takes joystick inputs, converts
them to the commands and sends them over the serial link to the ROV.  By using
a video capture card you could superimpose heading, depth and battery info
directly over the video feed from the ROV.  You could even mimic the head up
display on an F16.  One nice feature is that the microcontroller on the ROV
could be programmed to blow the ballast if it is unable to communicate with
the operator after a certain period of time.

I currently have much of this work finished.  I have written applications for
the Macintosh computer which can display images, in real time, from a video
capture card in an applications window, and I can superimpose text and
graphics over the images.  I have also written routines for communicating with
a serial port.  I own a Motorola HC11 development kit and I have been engaged
in programming the chip.  

Does anyone have any experience sending both serial data and video information
over a single cable?  I think one could connect a wireless modem's attenae and
a wireless video broadcasting unit's antennae to a single insulated cable
while using the sea as a ground.  But I have never tried it.

My first program for the HC11 will control a solenoid valve which will release
oxygen when a Ceramtec oxygen sensor indicates that the ppO2 of oxygen dips
below 20%.  I plan to build a closed circuit rebreather which would be
beneficial for both diving and manned submersibles.  After that I plan to use
the HC11 for robotic applications.

Steve Svoboda