How to emulate USB devices?

Question

The rest of my team will make for my application a simple non-standard USB microphone, but until they finish it I will have to emulate it, for integration testing purposes.<

Answer 1

You can write virtual USB device using QEMU. You can duplicate already existing device, like the dev-serial.c found in this QEMU repository and change it for your needs.
After you write and compile your USB device you can simply attach it to your VM using the QEMU command line interface.