I know the title is phrased terribly, but I'm not sure how to phrase it since I'm not sure of the name.
I have a servo, that I cannot connect to, except for the output spine/shaft (physically). I need to get the output of that servo into an arduino, or raspberry pi. So I need some kind of peripheral that can attach to the shaft of the servo, and tell me what position it's in. I can't figure out how to find what part I need, because I can't google for the name of it correctly. I've tried servo input shaft, and many other things that don't make sense.
I have a servo on a machine, and I can not interface with this servo in any way but physically. I can't read the output from it electronically, and the signals are proprietary. I can't take anything apart, all I can do is put something physically on it.
So, the issue is, I need to (based on nothing but the position of the servo shaft) figure out what position that 3rd party servo is at.
With that information, I'm then going to man in the middle, and attach another servo to my device, and change the value to what I want.
So if the factory servo is at 50%, and I know that by using something like a rotary encoder, if that ends up being the answer, I then could add x% to my actual servo.