Hello all,
    I use a separate connector for my power and signals. I arrange the=20
pins in the power connector in such a manner that if it is plugged in=20
backwards nothing will happen. It is amazing how some people can force a=20
two inch diameter rod in to a 1 inch hole, I make sure that the signal=20
connector doesn't have any voltages on it that can damage some thing if=20
it should be plugged in backwards.
Thanks,
rich!

On 8/26/2015 2:07 AM, Jesse Lackey wrote:
> Hummm.... neat question.
>
> One aside: if the connector isn't polarized, you could use strategically
> place the spare pin such that if the connector is inserted backward and
> power applied, the +12V goes to this unused pin, and the user gets
> nothing happening vs. smoke.
>
> Can you arrange things such that you aren't sampling the analog sensors
> while motors are running (or starting/stopping), or solenoids switching?
>    Or maybe at least take an average over time to minimize bad data.
>
> Digital I/O ... it would be best if all signals are driven, i.e. not
> have pullups, for better noise immunity.  Not sure how much it matters.
>
> You could use that spare pin for a ground for digital and/or analog, and
> have the digital and/or analog ground therefore be separate from the
> rest, and connect the grounds together where the power comes in from
> whatever is plugged into this and making the +12V.  That said, I have
> seen cases where the best performance was to use the same ground all over=
..
>
> A ferrite on the +12V @ the connector would be a polite thing to do,
> maybe on the motor as well.  They're cheap.
>
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.