John,
I use an Arduino Nano AD9850 external vfo? with my Corsair II, that uses a free turning optical encoder and the Corsair digital display.
Currently working on another version with a 20 x 4 lcd display, 2 memories, changeable step sizes and RIT.
Also has up/down band buttons?so the lcd shows the same frequency as the Corsair, when on normal sideband.
My objective was have a free spinning tuning knob and to avoid mechanical pto wear problems in the rig and external vfo.
Using the Raduino with cat is certainly in the realms of possibility but you would?probably need to add a buffer amp and?certainly a low pass filter.
73 Bob GM4CID
