Hi,

I read the example and start using hidapi. The read and write function work fine with mbed USBHID_HelloWorld example.

I found there is a api hid_send_feature_report. I call the function but mbed USBHID does not receive anything. Is feature report implemented in mbed libraries?

Could I just use output report to do configuration to my mbed device or I have to use feature report to do that?

Thank you in advance,

Cid

Hi Cid,

No, the feature report is not implemented in USBHID.

I think that you can use output reports for that. According to the first output report that you send from the host, you will configure your mbed accordingly.

Cheers, Sam

Thank you Sam.

So, could I say that I actually don't need feature reports to do settings change to the devices like changing LED color of the mouse because I can do that by output reports?

What feature report is for if it is replaceable by output report?

Thank you very much,

Cid

Hi Cid,

The main difference between input/output report and feature report is that the latter use the control endpoint whereas the former uses interrupt endpoints. The feature report was conceived to transfer configuration information and input/output report the real data, but all can be done with just input/output reports.

As input/output reports are raw data, you can imagine designing a protocol on top of HID to do the configuration of your mbed. If you are using USBMouse, it's different as the mbed does not receive output reports.

Cheers, Sam

Thank you Sam.

Really appreciate your explanation.

Best Regards,

Cid