Hi Andy/Folks,
Thanks for the info see below for a few points...
>
> The "how" is best covered in a high school or better Physics text.  The
"when"
> is "whenever you can."
>

OK so another question (which I'm going to create a new thread for) is what
books/web-sites etc. are around that give a good coverage of these sorts of
issues - PCB design, layout, ways of dealing with noise etc. How did you
learn about doing this sort of stuff? How do you know if it will work?

> >OK so in my project I only have a single 12V supply (no extra pack for
the
> >radio gear). Any suggestions on the best way to set things up to provide
> >power to the "noisy" power part of the system, the pic based part and the
> >radio part from the same supply?
>
> OK, but seeing your application, you aren't in a noisy environment.  I
race
> "targets" at 50 MPH, with 60A+ loads on the nicads.
>

Yeah I know that my problems are not as bad as yours, however a sub does
have a few issues of it's own. The signal levels drop very quickly as you
dive so noise often becomes a problem. Also I'm not as good as you at fixing
these problems so avoiding any noise is good for me! What would you advise
as a good power supply setup for the above? Would it help/make sense to have
a setup like the one you described for the pic side of things then a
separate LDO regulator for the R/C stuff, any advice on the best
configuration for the regulator etc. for the R/C stuff?


>
> I did all the PIC stuff that's in Skip Asay's (SubTech = www.rcboats.com)
items
> and I'm constantly working to upgrade them with him.  Tonight (I hope) to
finish
> up yet another X-tail mixer version for him.
>
> Couldn't say that a few months ago, as he was still using Sergio's speed
> control.  Not Any More!! <VBG>  Sure looks a lot like yours, except the
new one
> is in a 4 MHz 12C508 and his was a 16 MHz 16C54.
>

And it all works really well. If what I wanted was to get a sub up and
running quickly and working well I'd just go out and buy the stuff from
Skip. But that would be no fun, one of the major reasons I'm into subs is
the "interesting" control problems you have. I enjoy trying to build my own!

> If I were doing something like you are, I'd go with the multi-chip
approach.
> Basically, you already have certain portions working with an RC-style
interface,
> right?  So have the 876 drive them using that interface, with a 74-series
or GAL
> chip to select the appropriate device to be controlled.  Then you have a
LOT
> more memory and time available to do the calculations.
>

Once again I'm sure that the above is the best way, but I quite like the
idea of seeing how much I can get out of one chip - obviously if I was doing
this for a living the amount of time I'm going to waste on this would not
make sense but this is my hobby I like making things hard for myself! I'm
also going to re-write the whole lot in C this time around, ASM is fun but
I'm getting a bit fed up of making things really hard for myself. Also the
algorithms are getting more complex and it is hard to see exactly what you
are doing in ASM (wood and trees sort of thing).

The other thing I really want to include this time is...
a) The ability to tune most of the stuff at the waterside so I can reduce my
test time.
b) In circuit programming so when things get bad I fix it. Though is does
mean I'm going to look even more of a geek, you don't get many people
plugging a notebook into a boat in my local club!

Thanks

Andy