Go to the main menu (Start)
Go to controller settings
Go to Configure Controller
Brings the Gpi case into Axis mode. Hold SELECT* + D-PAD LEFT for 5s. The device led will flash purple when done.
*SELECT may have been replace by START on new firmware.
Set up your controller.
High
Down
Left
Right
Joystick can be skipped (press D-Pad down 4x)
A
B
X
Y
Start
Select
L1
R1
Skip L2, R2, L3, R3 again (press D-Pad down 4x)
Hotkey (press Select)
Press B to finish OK

Right B and A button in the SNES
The D-Pad works with Scummvm