Re: [PSUBS-MAILIST] Through Hull Connections

[Jeff Post <jeffpost@rawbw.com>]

Hi Peter,

I read Dan's response to this one, and it is right inline with my comments. I
don't think you should complicate things with networks of computers and
instruments. Dan is right to say that you would be best to manually control
everything, at least to start. If you are a sophisticated electronics + computer
+ software person, you could expand later. You always need to worry about how
you will operate when things fail. You alluded to this yourself with the air
scrubber and a power failure.

I have this vision of you being negatively bouyant, getting the blue screen of
death, and it's one of those times when, somehow, the reset switch doesn't seem
to work. One of my favorite lines was someone saying he wanted a picture of Bill
Gates on the reset switch so he could punch him in the face every time Windblows
crashes! 

Basically, the simpler you can make things, the more likely you'll sucseed in
building a psub project, and the more likely you'll be able to use and survive
your project. It is very much like boats, the more crap you add on, the more
time you'll spend installing and repairing, and the less time you'll spend boating.


Jeff


Quoting mckellar@earthlink.net:

> 
> Obviously I will need some power inside the hull, but I should be able to 
> keep the demand fairly low.  The thing that concerns me the most is the 
> requirement for over 100hrs life support.  without something to pump air 
> over the scrubber and monitor and control essential systems, any other 
> 'failsafes' (eg lots of air/oxygen) become next to useless.  do i put a 
> bicycle type driven fan or generator on-board? (i jest, but it has some
> merit).
> 
> Which brings me to another question.  I'm assuming with joystick control, 
> various sensors, cameras etc more than one computer is really required for 
> control etc.  Is the solution to make everything dumb except the laptop/PC 
> or do you run a lan?  if a lan, wireless or cabled?
> 
> If cabled to things outside the hull, the same sealing problems occur.  if 
> wireless, that avoids thru hull connections, but how far is the signal 
> likely to transmit through saltwater (given that different manufacturers r 
> likely to have different broadcast strengths)?  then of course i have 
> to   have a client out-board to control thrusters, trim etc 
> <sigh>.  <warning: hopelessness and despondency follow :) > so many 
> problems at every turn :(  my speadsheet with specs is huge and still 
> nothing I'm really happy with.  The AutoCad 2000 solid modelling im 
> dabbling with is like a kids scribble :(
> 
> cheers
> peter