I picked up an old Sony BVS-3200 broadcast vision mixer from ebay (my first experience of the Global Shipping program and it actually works).
I’m still undecided whether I will be able to use the panel through the existing serial interface (need to get a frame to decode the messages), rip out the microprocessor and put in an Arduino (requires reverse engineering all the logic) or gut it for the parts to build my own panel.
Just testing the T-Bar as it is non-destructive to remove it for testing. Rather than using a potentiometer, Sony used a rotary encoder that outputs pulses (must be a technical name for this which I’ll find on Google eventually).
It actually outputs 2 signals so you can detect the direction by which line goes high first.
I get 536 counts from full movement of the T-Bar.
PowerShell and demo video showing this controlling the Blackmagic Design ATEM fader coming soon. In the mean time I’m also converting an old EchoLab MVS panel but that uses very simple circuit by the look of it so I’ll be replacing its Z80 processor with an Arduino.