A servomotor is a rotary actuator that allows for precise control of angular position, velocity and acceleration.
Manufacturing defects in servomotor can make that it can not do the complete 180º movement that is indicated in the package.
Using arduino, if you tell a servomotor to move to a position which it cannot take, it makes no movement at all.
Normally, servomotors loose movement capacity by the sides of the angle.
This program help to discover the real angle that a servomotor can do (angular positions interval).
Output example with Arduino IDE serial monitor
