In all of Keil's USBHID examples, there are two items in the Report Descriptor called UsageMin and UsageMax.
Thy are set to 1 and 3. I have reviewed the USB Usage Spec and several other examples and I still don't understand the need for these two items of range.
I can find no other example of these two items. In MSDN2, I find the HIDP_Value_CAPS structure that includes the RANGE.UsageMin and RANGE.UsageMax that tells about the bounds but what is their use?
In Keil's HIDClient code, I see no place where the two items are used. Of course when I comment out the two lines of code, the code fails. Probably I'm breaking an array count somewhere when I comment out the code.
I'm hoping that someone like Tsuneo can educate me on the two items. I have sent a query to Keil Support but it will be awhile before I expect an answer.
Al Bradford

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