I think it cannot detect if a cable is inserted or not.
But, assuming that the internal mixer vca works with a cv range from 0 to 2.5 volts, it could work like this: (beware of my epic paint skills)
The voltages of the pot and the cv in are summed via two resistors. Then, if the pot is fully turned left, you got full cv control. If you turn it up, it will act like an offset i think?
In case there is voltage present on both inputs of the summer, the output voltage can reach more than 2.5 volts, so you‘ll have to limit it somehow, maybe with a diode?
Disclaimer: neither do i own the module nor do i have any substantial knowledge in electronics, so this is just a guess
I think it cannot detect if a cable is inserted or not.
But, assuming that the internal mixer vca works with a cv range from 0 to 2.5 volts, it could work like this: (beware of my epic paint skills)
The voltages of the pot and the cv in are summed via two resistors. Then, if the pot is fully turned left, you got full cv control. If you turn it up, it will act like an offset i think?
In case there is voltage present on both inputs of the summer, the output voltage can reach more than 2.5 volts, so you‘ll have to limit it somehow, maybe with a diode?
Disclaimer: neither do i own the module nor do i have any substantial knowledge in electronics, so this is just a guess
Afaik 'true input detection' is usually done in Eurorack via the ground connections supplied by the 3.5mm Jacks, which is not possible in AE. I think your circuit is almost good, only the passive 'summing' technique is not very stable, usually An active summing stage with an opamp is used. (Google 'opamp summer circuit' for some good info)
I can imagine that digitally it might be possible: you monitor the pin, and if it is more than a certain threshold, eg 0.1V, you consider that this means a cable is connected. You would need to bias the pin to ground so it is surely at 0V when no cable is connected.
