Incorrect comments in HID.cpp

GoogleCodeExporter commented 9 years ago

I'm poking around in the HID.cpp file, working on turning my arduino leonardo 
into a joystick (which is working), and have found a few incorrect comments.

In the RAWHID section:

#if RAWHID_ENABLED
    //  RAW HID
    0x06, LSB(RAWHID_USAGE_PAGE), MSB(RAWHID_USAGE_PAGE),   // 30
    0x0A, LSB(RAWHID_USAGE), MSB(RAWHID_USAGE),

    0xA1, 0x01,             // Collection 0x01
    0x85, 0x03,             // REPORT_ID (3)
    0x75, 0x08,             // report size = 8 bits
    0x15, 0x00,             // logical minimum = 0
    0x26, 0xFF, 0x00,       // logical maximum = 255

    0x95, 64,               // report count TX
    0x09, 0x01,             // usage
    0x81, 0x02,             // Input (array)

    0x95, 64,               // report count RX
    0x09, 0x02,             // usage
    0x91, 0x02,             // Output (array)
    0xC0                    // end collection
#endif

Specifically:
    0x81, 0x02,             // Input (array)
    0x91, 0x02,             // Output (array)

In both of these cases, the comment specifies that the data type is an array.
However, if you look up the bit-mapping from the HID specs:

Bit 0    {Data (0) | Constant (1)} 
Bit 1    {Array (0) | Variable (1)} 
Bit 2    {Absolute (0) | Relative (1)} 
...

You can see that a value of 0x02 for the data type specifies a variable, not an 
array.
It should probably also be specified that since bit 0 is not set, this is data, 
and since bit 3 is not set, the value is absolute, to make this section match 
the other descriptors in the file.

Anyways, I have been going through and fairly extensively clarified the whole 
HID descriptor section with some #defines, replacing the various hex constants 
with what they actually mean as a #define macro.

The attached file can replace the existing HID.cpp file with no changes.
It also has the the descriptor needed to turn a leonardo into a joystick, 
though it's currently turned off using a #ifdef.

To make things work completely, you also need to add a few lines to USBAPI.h, 
so I'm attaching that too.

You can see an example for how to use the joystick additions on my website, 
http://www.imaginaryindustries.com/blog/?p=80

Original issue reported on code.google.com by Lem...@gmail.com on 10 Nov 2012 at 12:46

GoogleCodeExporter commented 9 years ago

[deleted comment]

GoogleCodeExporter commented 9 years ago

Hangon, there is a #define collision somewhere, that the arduino compiler is 
not reporting.

Trying to troubleshoot now.

Original comment by Lem...@gmail.com on 10 Nov 2012 at 1:22

GoogleCodeExporter commented 9 years ago

[deleted comment]

GoogleCodeExporter commented 9 years ago

Never mind, it wound up being a stupid assumption about how I could pack pack 
multiple-bytes into an single statement in a variable definition, along with 
the fact that the arduino environment eats all the compiler warnings.

Here is the patched HID.cpp

Original comment by Lem...@gmail.com on 10 Nov 2012 at 1:52

Attachments:

andyvand / arduino

Incorrect comments in HID.cpp #1107