I'm guessing here - using an op amp as a differential amplifier and
level shifter, would possibly help you a lot here.  (Assuming your AC
voltage dips below Ground.)

Set the op amp gain up to give you a reasonable swing on the output,
resistor or zener from that output to PIC input pins, pull-up resistor
(weak) to +V from there;  you want to set things up so that you get 2.5V
at the PIC input pin for a "Zero" input, and the gain of the op amp is
set to map the maximum input voltages to +-2.0V or so output on the
output end of the op amp.  IIRC I just used a resistor - use a Zener if
that +V is unregulated, and I think there's a trick to THAT one that I'm
not remembering still - I'm not a linear guru, the last time I did this
I
did it something like that, it's been a while and "If you don't use it,
you lose it" partially at least.  Hoping this gets you unstuck.

How accurate of ADC reading do you need?  Do you need differential AC
voltage readings, to track each voltage independently, RMS readings, ???

  Mark

Darren King wrote:
> I'm trying to read information from an alternating type current.  It starts
> positive ends up negative and then repeats and some crazy frequency.  Does
> anybody know how I'm supposed to hook up 2 Analog lines to my Pic16F788.
> When neither is ground?  And then after that how would I read it to get the
> relevent Data something like 2,1,0,-1,-2,-1,0,1,2?
>
> This ones been killing me.  Thanks
>
> Darren King

--
I re-ship for small US & overseas businesses, world-wide.
(For private individuals at cost; ask.)