Many radio amateurs are not fans SDR black box devices. They argue that, that they lack the front panel of the device with the tuning knob. JI1UDD felt the same way. However, the prices of original accessories are staggering. One possible solution is described in the article Remote station (SDR) tuning knob. But he created JI1UDD based on the microcontroller Arduino Pro Micro, rotary pickup and four push button MIDI controller for VFO tuning and control of tuning related functions.
Necessary components for VFO MIDI controller via USB
Arduino Pro Micro : 5V / 16MHz (AliExpress)
Rotary sensor : KY040 sensor can be used (AliExpress). In my case, RE160F-40E3-20A-24P in my stock is used.
Push button switch and cover : (AliExpress)
With Control-Surface's nice midi library, almost no programming is required.
It is made using a 3D printer. I used a knob taken from an audio kit.
Thetis and PowerSDR setup
The rotary encoder and switches can be freely configured. Here is the JI1UDD setup:
I found a helpful video on Youtube for configuration:
You can find the entire procedure in the documentation https://github.com/ji1udd/VFO-Controller