EHX Stereo Memory Man Hazarai preset footswitch?

[DWBH]

I'd like to make an external footswitch to scroll through presets in the Hazarai.
The pedal uses a rotary encoder (2 pin) to scroll through the presets. I imagine there's a decoder somewhere that outputs a CW pulse and a CCW pulse. I've actually traced a bit that's near (physically) to the encoder. There's an IC and three capacitors that I can see (besides two 10k resistors). The marking on the IC is either PFN1 or PFNI.
I can't remove the board, thus I only see one side of the board.

Idle voltages (without rotating the encoder):

Pin 1: -6.17v
Pin 2: 6.35v
Pin 3 : -3.35v
Pin 4: ground
Pin 5: 3V


The encoder and the said chip (U11, caps are C31,32 and 33) are located in the top left corner.

Any hints?
I can't find any information on this IC. I was hoping it was some kind of flipflop. I'm guessing it would make things easier

[MarcoMike]

first of all: I don't understand digital things at all.
but my guess is that those 2 encoder pin must connect to something else too. or does it work like that already??

[cloudscapes]

the side fo the board you can see with the two 10k resistors is probably just the pulldown resistors. encoders tend to need those.