Sep;

I gots some advice to toss on your pile.

Your Hbridge has a power and return wire coming from the power supply (2V and
ground).  The logic portions also have a 2V and ground.  Bring these two pairs
back to your source of power seperately.  Place the filter cap at the source of
power, where the wires come together.  Add a smaller filter, say 10uF and 0.1uF
at the pic itself.  Don't forget the 0.1, as the electrolytic is nt nearly as
useful for high frequencies.  Pull the MCLR up with  a 5 to 10K resistor.

When you lay out a board, try to implement this in the final PCB pattern as
well.  A nice solid ground trace is nice, but make sure that motor current does
NOT pass through that ground trace past the PIC itself.  They should arrive
seperately at the origin.

Also, try hard not to implement loops in the PCB pattern, such as a ground
trace all the way around the board.  This makes the ground trace susceptable to
magnetic fields in the near field (motor) and to a lesser degree,
electromagnetic (magnetic protion) in the far field (RF and florescent lights).
(A pure electric field or pure magnetic field transforms into an
electromagnetic field at some defined distance from the source of the field, in
a ratio that is related to the impedance of a free wave in space).

Chris Eddy
Pioneer Microsystems, Inc.

sep wrote:

> Hello all,
> I got some sleep!
> Ok.
> So I am now gonna put a 1000uF cap accross the power supply for the pic.
>
> Now for the MCLR what should the exact condition be if I want to be able to
> put a switch there too...?
>
> Right now it is going STRAIGHT to high so this may indeed be the problem as
> some have noted.
>
> Thanks. Let's hope I get somewhere today!!
>
> +--------------------------+
> |  Sep Seyedi              |
> |  -> me@sep.2y.net        |
> |  -> http://sep.2y.net    |
> +--------------------------+