Controlling a servo
A servomotor is also defined as a rotary actuator that allows for very fine control of angular positions.
Many servos are widely available and quite cheap. I have had nice results with a 43 R servo, by Spring Model Electronics. You can find the datasheet at http://www.sparkfun.com/datasheets/Robotics/servo-360_e.pdf.
Servos can drive a great amount of current. This means that you wouldn't be able to use more than one or two on your Arduino board without using an external source of power.
When do we need servos?
Whenever we need a way to control a position related to a rotation angle, we can use servos.
Servos can not only be used to move small parts and make objects rotate, but can also be used to move the object including them. Robots work in this fashion, and there are many Arduino-related robot projects on the Web that are very interesting.
In the case of robots, the servo device case is fixed to a part of an arm, for instance, and the other part of the arm is fixed to...
