Servos are cheap devices that typically produce angular motion depending on pulse modulated (PWM) input signal. The control puleses have duration from 0.4ms to 2.4 and repeat every 20ms. Servos are handled by Arduino and Energia Servo library. Also libmaple has special support: example Servos need 5V supply voltage. However, control signal may come from 3.3V processor. Servo has 3 connecting wires: brown is ground, red is power and yellow is control.