sending more then the Report ID on a get usb report request.

[ulao]

Struggling with something here..

say I have a call like this
usbGetReport(dev, USB_HID_REPORT_TYPE_FEATURE, 17, buffer.bytes, &len)

I could easily add this to my report descriptor and handle the 17 request and return data. I do this an all works out fine. but I really need to send more data then just a report ID. I want to send an extra byte but do not want to do a send report first. Is there a way to add a parameter to my descriptor for this?

    0x85, 0x11,                    //   REPORT_ID (17)
    0x95, 0x06,                    //   REPORT_COUNT (6)
    0x09, 0x00,                    //   USAGE (Undefined)
    0xb2, 0x02, 0x01,              //   FEATURE (Data,Var,Abs,Buf)

Or is it only possible to send a report ID. I know that my wLength is the size and the wValue only has two bytes report + type but there is also a the wIndex. I'm not sure what this is for or if I could even use that. If I did I might be miss using it.

 I believe the correct path is to make multiple report IDs but I'd like not to do that as it will increase the maintenance on my descriptor.  To put this is a more functional description I want to do this.

Code: [Select]


if (strcmp(data1, "controller") == 0 ) commandRequest=0x01;
if (strcmp(data1, "pause_state") == 0 )  commandRequest=0x04;
if (strcmp(data1, "model") == 0 ) commandRequest=0x10;
if (strcmp(data1, "modes") == 0 ) commandRequest=0x18;

//but where do I put commandRequest?
usbGetReport(dev, USB_HID_REPORT_TYPE_FEATURE, 17, buffer.bytes, &len)
I did look in to custom types

usbGetReport(dev,commandRequest, 17, buffer.bytes, &len)

but there was not much help on this out there. Again, maybe I'm just looking to cheat the methods here but this would be so much more simpler.

[Jan Axelson]

In the Get_Report request, wIndex must be set to the interface number the request applies to.

You are correct that the correct path is to use multiple report IDs; that is their purpose.

One way around it would be to define a report that contains all of the possible data in a defined format. Then the host can choose whatever data is of interest from the report. The single report will be longer, of course.

[ulao]

haha, very clever