[simpits-tech] More on USB

[Matt Bailey]

On Thu, 18 Sep 2014 07:01:52 -0700 (PDT)
geneb <geneb at deltasoft.com> wrote:

> On Wed, 17 Sep 2014, Matt Bailey wrote:
> 
> > I realize changing the wiring around can help, but that's not
> > practical in many cases...especially with the Sabreliner having its
> > ENTIRE wiring harness still fully intact!!! I didn't know going 90*
> > was a fix for the AC issue....trouble is, if I did USB to anything
> > inside the cockpit, I would have very long runs of USB that need to
> > go in the same direction as existing AC lines (mostly for
> > lighting). Are you saying just a single 90* bend somewhere would
> > help?
> >
> You want to cross ANY AC bus at 90 degrees and not run parallel to it.

I guess I'm having trouble visualizing how I can run my low voltage
stuff 90* to AC lines that go lengthwise through the cockpit and still
actually get the ends of the low voltage wires up to the nose. :)

> If it was ME and I was in your shoes, I'd keep all the control
> electronics in a cabinet outside the cockpit.  That way your USB
> cabling is no where near the AC busses at all.  For those systems
> that require more localized control, I'd put the Arduino (or
> whatever) in the nose, going the opposite direction of the AC wiring
> in the overhead & sidewalls.

Actually that is more or less what I'm planning. Since the wiring
harness is still intact, pretty much every
switch/light/buzzer/radio/gauge etc has its wiring in a huge ugly
bundle at the rear right corner of the cockpit, or going to the
original avionics racks in the nose. I deliberately designed my
altimeter interface, for instance, to keep the Arduino and other
goodies in a box separate from the altimeter. The only wires going to
the back of the altimeter are the logic wires to my sensor and pot, the
drive wires for the DC motor and the OFF flag, and the lighting wires
(which may get split off if I keep this instrument on the original AC
bus).

All this logic stuff, as well as my computers, will be mounted on
the floor of the trailer that I'm putting the cockpit on, right
behind the rear bulkhead (so, directly under the false floor of the
instrument room). This will help with EMI issues, and it will also make
maintenance MUCH easier....believe me, after building my first sim, I
have really learned my lesson about burying microcontrollers and
breadboards deep within the innards of the panel. :)

-- 
Matt Bailey

Keeping It Real:
Sabreliner 60 Flight Simulator
Serial # 306-61 - N1JX
http://sabrelinersim.com