3-4 Chapter 3: Programming
The report descriptors as emitted by the HID device should be
consulted as the authority for the format of the reports. Software
should access fields using report descriptor-based techniques and
should not assume that all revisions of the product use identical report
descriptors. The following provides interpretation information for
these reports.
Keylock hardware HID interface: The keylock reports its
positions as HID buttons. The positions are assigned as follows:
• Button 1 = Ex
• Button 2 = L
• Button 3 = R
• Button 4 = S.
Tone hardware interface: The ErrorTone usage collects a tone
output report that sounds an immediate tone. The KeyClick usage
collects a tone output report that sets the sound made for a key
click. The units for Duration are milliseconds. The volume is a value
between Logical_Minimum (silent) and Logical_Maximum (greatest
volume). The tone is an index from Table 2: Note Numbers and
Frequencies.
The MSR interface: The MSR conforms to the USB HID standard
for MSRs as described in the HID Usage Tables for POS, Ver 1.02,
see http://www.usb.org/developers/hidpage.html#pos
.
The Key Matrix: The Key Matrix report contains an overlay for the
keyboard look-up table. It is organized in FPGA Offset order, and
contains pairs of 8-bit usages, one pair per key position. Values of
zero produce no usage report. Two different usages produce two
simultaneous usages being reported. The number of positions is
given by the report descriptor.
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