Erik, the flow meter I am using outputs pulses. I do not know what quadrature is. I am trying to post a circuit...but I think i could explain it in words. The FM has 3 leads. Ground, Vcc and Signal. Ground is connected to common ground in the circuit which is Vss in the micro. Vcc is 3.3volts. The signal is going into INT1 Pin, with no resistors or filter circuits at all.

__________
I I__________ Vcc
I I
I FM I__________ GND
I I
I________I__________ Signal =====> INT1 of MC