I've made enormous progress the past few days!!!!
I create a new MIDI Effect VST3 Plug-in which has all of the lathe interface buttons mapped allowing for Sample Locked control remote control of every function via MIDI notes. You can also MIDI Learn any of the functions and enter them that way or use them whenever you like from a USB connected MIDI Controller. Control messages are routed from your DAW over USB to my devices, and then over UART into my PLS-21 Portable Vinyl Lathe. I demonstrate Pitch Start and Pitch Stop. Though every button is working. And, I'm getting feedback too so I can change the VST Interface state to reflect using the physical buttons to change any parameter like RPM or Disc Size, etc.
I've also integrated the Pitch and Cutting control buttons into the VST3 Audio Effect Pitch/Depth Computer. But, you can't sequence them from an Audio track... Only from the MIDI implementation. You can however use them for handy control from the P/D Comp interface. This keeps you from having to change track focus in your DAW to see the other plugin interface. All the functions you would want to use in real-time are at your fingertips while you have the P/D Comp track selected and interface visible.
I added meters for both Pitch and Depth PWM output. So, you can see value changes more discretely than you would otherwise with just the LED's. And, I'm actually controlling both the Pitch Motor on my lathe, as well as the Suspension Box's Depth Solenoid. All changes to Pitch and Depth are faded from one value to the next. This avoid sudden drastic changes to pitch. You can both see and hear the pitch motor speed varying along with the audio playback in this video!!!!
Much, much, much more soon. But, I think this suffices for now.
Stay Tuned ;-)