The Yocto-Servo device will let your software drive up to 5 RC servo-motors through a standard USB interface.
This device handles two power sources for the servo-motors. For low-power applications, the servo-motors can be powered directly from the USB bus. For higher loads, use the external power connection provided on the device. The switch from one power source to the other is automatic, but can be controlled by software.
USB cables and enclosure to be ordered separately.