Can piKEY KEYBOARD DRIVER support a USB keyboard on psp2000!

[weiyiguo]

Hi !
as i see,this keyboard driver support IR or Serial I/O cable.but,i dont have a IR keyboard(psp2000 doesnt support IR I/O either) and i dont know how to MOD a keyboard via PSP's headphone socket.
so:
1,Is there any way to make piKey to support a USB keyboard?this picture explained my idea. its a mini USB keyboard used for UMPC or NOTEBOOK.

2,if not. how to DIY this keyboard to connect psp2000 via headphone socket.
Could somebody here send me some doc about psp's headphone socket I/O definition .
THX!

[Art]

1. No

and

2. Probably not since all the documentation is already here.

[weiyiguo]

DOES THIS WORK??
psp's headphone socket I/O<============>a mini USB keyboard
1,VCC (2.5V,maybe i will add a power)---------->1,VCC(5v)
1,TXD------------------------------------------->2,DATA+
2,RXD------------------------------------------->3,DATA-
3,GND------------------------------------------->4,GND


Then how do set pikey?i dont see anything helpful about using headphone socket to connect a usb in pikey Customer's guide DOC.

please ,please help me!~