Remote shutter release connections.

I have a remote shutter release it has a stereo jack plug and just like the main shutter release button light touch does focus and heavy does shutter.

I would like to build a remote trigger using a Arduino but however I try with meter I can't work out which contact is common and which is shutter and which is focus.

Can anyone help. Camera a K10D.

Hope this may help? link

Thanks nearly missed it the pin out was on a pdf at bottom end shutter centre focus and against cover is common.

No problem - glad to help.