tl;dr How do I scale frequency to DC voltage _out_ for a +/- 5V CV _in_?
I'd like to use the keyboard on my midi controller to send DC voltage to an analog synthesizer that takes +/- 5V CV in.
I have the midi controller going into Max ; it is bus powered, and has no separate CV out. I'd like to transpose the midi note from the midi controller in Max to a DC voltage out, probably via Arduino.
The way I'm thinking about it is basically scaling from [0Hz to 10000Hz] (or whatever notes I end up using from the keyboard) to [-5V to 5V]. But that just seems too haphazard of a way to scale it. I feel like it's much more complicated than that.
My exact setup is an Arturia Minilab (not the MKII) to Max 7 to a Moog Werkstatt-01. I basically want to extend the range of notes I have to choose from on my Werkstatt from 13 keys to a lot more keys. And I'm not using the keyboard on my Minilab at the moment, so I figured why not try to connect them instead of buying a CV keyboard.
I scoured the forums a bit to see if this has been done, because I'm sure some version of this has been done; surely someone has outputted CV to a modular or some other analog synthesizer from Max. I did not see anything that answers my question.