This is a USB class compliant HUI/MCU interface for the STM32F411 "Blackpill".
The .elf file allows to test on a board without having to compile the project yourself.
You can use the functions in "protocol" for different action without worrying about the HUI/MCU differences. A simple function allows the interface to detect HUI or Mackie Control Universal on plug-in. All track names, VU Meters states, select, mute, solo are stocked in arrays.
The USB function is herited from the STM32-USB-MIDI project.
If you're using the Device Configuration Tool and want to keep the USB feature, you must leave active the "USB_OTG_FS" under "Connectivity" and the "USB_DEVICE" under "Middleware".
Once the code is generated, you must delete the folders : "Middlewares" and "USB_DEVICE". They are not needed since the whole USB interface is already in the "Core" folder.
You'll also need to delete the " #include "usb_interface.h" " at the beginning of "main.c" (line 22).