USB Report Length

[Jo-Jo Smith]

Posted on October 25, 2017 at 21:34

I have the USB HID demo working on an STM32F072B-DISCO board. I grabbed the code from the HID demo app to make a custom Windows project. Everything works alright, but I want to increase the report length (the demo report length is 2). I changed the HID_IN_PACKET and HID_OUT_PACKET macros to 64. After my device enumerates, USB Viewer shows the wMaxPacketSize as 64 as expected. However, the HIDP_CAPS InputReportByteLength and OutputReportByteLength in my Windows app are still reporting lengths of 2.

How do I increase the input and output report lengths in the demo application?

[Jo-Jo Smith · Accepted solution]

Posted on October 27, 2017 at 01:43

I figured it out.

I needed to increase the report number, report size, and maximum logical value in my report description.