At 05:16 PM 15/07/96 EDT, myke predko wrote:

>Power Supply is providing a solid 5 volts, the spike is going from 5 to 5.5
>Volts and looks like:
>           |
>     ______|\_________
>
>on the scope (hopefully the ASCII art isn't too bad).  At the same time as
>the spike, there is a 200 mV spike on the "Ground".  I don't know how much
>this affects things; as I've said, the PIC currently runs very solidly with
>the two I/R Receivers and the motor running (to put noise in the system).
>
---- and also----
>The PIC does seem to run fine with the motors running with
>the negative voltage common to the PIC and the motors.

Can you explain how the power supplies to the motors and PIC are organised
and connected?  Are both supplies referenced and tied to the same common (-)
rail?  It would also be helpfull if you can indicate where in this setup
your scope was placed, specially the ground reference point for the scope.

It appears you may be seeing some induced emf in the ground plane, or I^2xR
losses, caused by the high current drain of the motors.

Paul.