Hi
I want to control a "rotation continue servo motor" in position. (FS90R)
Every where I'm looking for, they control the speed, not the position...
Is il possible to crontrol the position ?
Thank you 
Is il possible to crontrol the position ?
No, unless you add some feedback mechanism to the servo otherwise there is no way of knowing where the output is positioned.
Why are you using continuous rotation "servos" if you want to control their position ?
Your Right, it's not exactly the position I need to control...
I have to control the angle, like with a standard "servo 180°"
I maked a little robot with 2 FS90R, I thought I could also control the angles to make it go wheel turn by wheel turn. I did not know that the "continue servo motor" were so different to control than the "180° servo"...
I want to program a way to my robot, for example : 3 turn of wheels, rotation 90° right, 8 turn of wheels, rotation 90° left, 8 turn of wheels...
Do you know if it's posible ?
Thank you...
I want to program a way to my robot, for example : 3 turn of wheels, rotation 90° right, 8 turn of wheels, rotation 90° left, 8 turn of wheels...
Do you know if it's posible ?
You can want it all yoy like but with no feedback of the servo position you can't do it. The best that you can do is to run the servo for a fixed time at a known speed but it will be very innaccurate.
So, a 180° servo has been designed to control it's rotation angle with an internal potentiometer. And a 360° servo (same design, almost same name) is not able to do that...
It's disappointing... 
It's disappointing.
But not surprising as it is a continuous rotation "servo"
If you want better, but still not guaranteed, motor positioning than you could use a stepper motor or better still add an encoder to your "servo" output.
Thank you for your help UKHeliBob