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

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 It is 5V compliant, which means you can control it from a 3.3V Arduino and still safely drive up to 6V outputs 6 address select pins so you can stack up to 62 of these on a single i2c bus, a total of 992 outputs - that's a lot of servos or LEDs I2C-controlled PWM driver with a built in clock. No need to continuously send it signal tying up your microcontroller, its completely free running!