USB Joystick HID descriptor

Hi,
I wrote HID descriptor for Joystick, the joystick has 8 axis. I want

to know, is this right that Wheel and Dial usage for trim wheel and

flap axis and how can I add 8 buttons into the below code I have many

tried for buttons but failed?


0x05, 0x01, // USAGE_PAGE (Generic Desktop)
0x15, 0x00, // LOGICAL_MINIMUM (0)
0x09, 0x04, // USAGE (Joystick)
0xa1, 0x01, // COLLECTION (Application)
0x05, 0x02, // USAGE_PAGE (Simulation Controls)
0x09, 0xbb, // USAGE (Throttle)
0x15, 0x81, // LOGICAL_MINIMUM (-127)
0x25, 0x7f, // LOGICAL_MAXIMUM (127)
0x75, 0x08, // REPORT_SIZE (8)
0x95, 0x01, // REPORT_COUNT (1)
0x81, 0x02, // INPUT (Data,Var,Abs)
0x05, 0x01, // USAGE_PAGE (Generic Desktop)
0x09, 0x01, // USAGE (Pointer)
0xa1, 0x00, // COLLECTION (Physical)
0x09, 0x30, // USAGE (X) for ailerons
0x09, 0x31, // USAGE (Y) for elevator
0x09, 0x32, // USAGE (Z) for rudder
0x09, 0x33, // USAGE (Rx) for spoiler
0x09, 0x34, // USAGE (Ry) for throttle 1
0x09, 0x35, // USAGE (Rz) for throttle 2
0x09, 0x38, // USAGE (Wheel) for trim wheel
0x09, 0x37, // USAGE (Dial) for flap
0x95, 0x08, // REPORT_COUNT (8)
0x81, 0x02, // INPUT (Data,Var,Abs)
0xc0, // END_COLLECTION
0xc0 // END_COLLECTION