This video shows you how to use the 10 servo outputs (S1 to S10) on your Smartibot board to connect to Servo motors and other kinds of radio control hardware (like speed controllers). These functions are supported on the iOS from 1.0.7 onwards (if you think you might be on an earlier version please update) and will be on the Android app as soon as we are done with the A.I.
A Servo is a special kind of motor and gearbox unit that is aware of its position and is able to go to a set position (usually between 0 and 180 degrees) based on the value of a variable voltage supplied on the signal line. Smartibot has a special chip on it that is able to vary the voltage sent to the servos by switching on and off very quickly and varying the fraction of time that it is on or off (more time on = higher voltage). This technique is called Pulse Width Modulation or PWM for short.
Servos are very commonly found in radio controlled models, where they are used for steering in cars and moving control surfaces in planes. Other bits of hardware made for radio controlled models, like electronic speed controllers, can also be connected and controlled in the same way as Servos. Servos are also great for building robots with limbs or other things that need to move back and forward in a controlled way (rather than round and round at a controlled speed).