Hello I would like to realize a project using 4 servo-motors but I do not know which Arduino to choose (I am interested in the nano) to control them and also know if servo-motors types 9g (or cms-2 micro servo carson https://www.mg-modellbau.de/Servos/C...peech&speech=1) was controllable to the nearest degree (ex.126 °) and also what was their amplitude (in °).
edit:
can i control a continuous servo to the nearest degree ? and can he turn like 0 to 360 and go back to 0 without making a other turn in the opposite direction ?
can i control a continuous servo to the nearest degree
No, you cannot. Those "servos" have lost the feedback element that allows positioning. They are no longer servos, they are gear motors with speed control.
A Nano will easily control 4 servos. The Servo library allows 12 servos to be controlled.
Be sure that the power supply for the servos can supply enough current. Don't try to power servos from the Arduino.
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html.
Tom.... 
kriss525:
edit:
can i control a continuous servo to the nearest degree ? and can he turn like 0 to 360 and go back to 0 without making a other turn in the opposite direction ?
No. If you really need to go to any position within 360 degrees or more you need a sail winch servo. They will usually do at least 4 full turns with positional control.
Steve
thanks you all thats very helpfull