It doesn’t get easier than this when you want to control a servo via a serial port. The whole circuit only requires 4 parts, and that is including the servo. Now that’s a simple circuit!

A dedicated servo motor control IC has several obvious advantages, and is considerably less expensive than purchasing a large motor control board. This is especially true if you only need a single servo controller. Why buy a board with 8 or more motor capacity if you only need to control a single servo..?

Via Hack A DayDIY: Simple Servo Controller

 Media 16 Servo Controller16 servo controller