I am definately not using Nyko Playground to map (when I did try, nothing at all worked). I have the controller set to HID mode (none of the other mode worked even close to right). If this gamepad has the mode you mentioned (putting the left stick in d-pad mode), I haven't read anything about it... Both Mupen and the Nyko Playground register the left stick distinctly different from the d-pad...
I rechecked the button call-outs in Mupen, and I was mistaken earlier... The left stick does infact read out as AXIS_HAT_(X and Y), but the right stick actually reads as AXIS_(Z and RZ). I don't know if that makes any difference.
I could not find the manual online anywhere. I have the paper insert that came with it (it isn't very enlightening), but if you think it would be useful I can scan it in tomorrow and post it... The onlything online I found was the product webpage:
http://www.nykoplayground.com/product/playpad/It discusses the modes, but not too much detail. It does claim that the Playground app can switch the analog sticks, so I tried to do that. Very unsuccessful. I can't really figure out how there Playground app calls out the sticks (how you map an analog direction to a stick...) It doesn't really seem to have that capability, even though the app claims it. Regardless, like I said, if Playground is running it just confuses the Mupen mapping.
Do you have any other suggestions? Should I scan that paper insert?