I have a bit of a problem with generating a HID descriptor. I want to use simple reports with ID1 for input and ID2 for output with 64 bytes of data.

I realized that despite RTFMing and googling I still do not have a clue about some fields in HID descriptor.

What is a hint or a manual where I can find the meaning of all descriptor fields? All I could find was examples for HID-mouse, joystick, and keyboard.

For example - REPORT_SIZE - is it size in bytes or in bits? And why is there also REPORT_COUNT? If I have 64 bytes in the report, must LOGICAL_MAXIMUM be 255 or 255*64?

Should I write LOGICAL_MAX and MIN for every report or not?

Or maybe will this one (generated rather by guessing) suffice?

char ReportDescriptor[39] = {
    0x05, 0x01,         // USAGE_PAGE (Generic Desktop)
    0x09, 0x00,         // USAGE (Undefined)
    0xa1, 0x01,         // COLLECTION (Application)
    0x85, 0x01,         //   REPORT_ID (1)
    0x09, 0x00,         //   USAGE (Undefined)
    0x15, 0x00,         //   LOGICAL_MINIMUM (0)
    0x26, 0xff, 0x00,   //   LOGICAL_MAXIMUM (255)
    0x75, 0x40,         //   REPORT_SIZE (64)
    0x96, 0x00, 0x02,   //   REPORT_COUNT (512)
    0x81, 0x82,         //   INPUT (Data,Var,Abs,Vol)
    0x85, 0x02,         //   REPORT_ID (2)
    0x09, 0x00,         //   USAGE (Undefined)
    0x15, 0x00,         //   LOGICAL_MINIMUM (0)
    0x26, 0xff, 0x00,   //   LOGICAL_MAXIMUM (255)
    0x75, 0x40,         //   REPORT_SIZE (64)
    0x96, 0x00, 0x02,   //   REPORT_COUNT (512)
    0x91, 0x82,         //   OUTPUT (Data,Var,Abs,Vol)
    0xc0                // END_COLLECTION
};