EHX Stereo Memory Man Hazarai preset footswitch?

Started by DWBH, July 21, 2011, 05:42:23 PM

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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??
Only those who attempt the absurd will achieve the impossible.

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.
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Pedalnerd

bumb. Any progress on this, I would love to make a preset footswitch for my memory man with hazari

Tightpants

Are you sure it's a two pin encoder, I can't see how that would work? I'm not saying that you are definitely wrong but in my experience encoders come with either three or five pins. The three pin version has two outputs A and B and a common (C) pin. Pins A and B are quite close to each other inside the switch and can make contact with common through holes in a rotating disc. When rotating in one direction one pin senses the change first, when rotating in the other direction the other pin senses the change first. The outputs of the two pins are 90 degrees out of phase (thus the term quadrature). The five pin version is exactly the same but has two extra pins for a momentary push switch. I would go back and have another look, it's a pity that you can't get to the other side of the board, perhaps some pins have been bent over and soldered on the other side.