Thank you to Tysonpower (aka Manuel DO5TY) for submitting information about how he's managed to convert a cheap €14.33 USB audio control dial into a VFO tuning knob for use in SDR programs like SDR-Console V3. He writes:
I sometimes miss a VFO Knob while using my SDRs, especially with SSB Signals or CW where you need to adjust the Frequency very fine.
Because of that I got myself an Audio Dial with USB, reverse engineered it somewhat and wrote a new Firmware for the STM32 used in the USB Dial.
It all worked out and it now simulates a mouse wheel with three different scroll speeds. There is also a Mute Function when you long press the Button.
I had a lot of fun during this project, even when it was a lot of time just for a VFO Knob :)
Manuel's blog post goes into deeper detail on how he reverse engineered the knob and how he re-programmed the STM32 microprocessor. He also includes the HEX file if you want to purchase the same unit and reflash it. His video below shows the modified knob in action.