RockBand 3 Mustang Guitar controller for wii and jinput

This game controller is also a midi controller, but is not realistic.
So, i’m trying to do a java app that catch the wii controller signals and send midi commands to a port.
I’m just begining, so i’m trying to get the diferents values of the component.
I’ve seen that each botton that emulate the strings E,A and D, correspond to values of Rotation Z and axis Z.
But i don’t get any signal when a press a botton of the others “strings”, neither when i pull o hit, one of the six strings that this controller has.

My program at begining shows the values of all components, Rotation Z an Z axis have -1 (both)
but y and x axis start with this value -1.5258789E-5.

Can anybody give an idea about this?

thanks a lot and sorry about my english