do you think it’s possible can make a diy joystick, using Arduino and connected via midi to a4 to reproduce the features it has on analog key?
yes.
it’d be a lot simpler and controllable with a few outboard sliders/mw, or even the onboard perf knobs sorta - so whilst the answer still remains yes - i’d urge you to think of the advantages of controlling three parameters with either one stick doing this
North = Control A, South = Control B, East/West = Control C
or controlling it with other stuff, linked or otherwise, the only thing to think about may be the bi-directional nature of some controllers (bend etc)
a joystick is just two pots, i’ve replaced the joystick on some of my stuff with them because it’s kinda more fun for some things.
but yeah with the arduino i think you’d just send the 2 +5vs out the two connectors on the joystick, ground it, read them back in, convert to MIDI? there are MIDI shield kits.
^ the Elektron joystick addresses ‘three’ groups of parameters by discerning between up from centre and down from centre if you’re wanting the full AK clone on the cheap