Adafruit 16-Channel 12-bit PWM/Servo Shield - I2C interface

Description

This handy PWM and Servo driver shield will allow you to easily create multiple moving parts in your next project. It's just like the popular PWM/Servo Breakout but now Arduino-ready and works with any Arduino that uses shields: Uno, Leo, Mega, or ADK.
This chip will allow you to control 16 free-running PWM outputs using only two I2C pin. As well, it will allow stacking of up 62 shields to control up to 992 PWM outputs. Because I2C is a shared bus you can also connect other I2C devices and sensors to the SCL/SDA pins as long as their addresses don't conflict (this shield has address 0x40).
Other features include:
* 5V compliance, so that it can be controlled from a 3.3V Arduino and still safely drive up to 6V outputs
* Adjustable frequency PWM up to about 1.6 KHz
* 12-bit resolution for each output - for servos, that means about 4us resolution at 60Hz update rate
* Configurable push-pull or open-drain output