The PCA9685 servo driver module is used applications where large number of servo motors are used such as robot arm, hexapod and robots. It increases the number pf PWM output of your microcontroller.

Using only two pins, you can control 16 free-running PWM outputs. That means that, you do not need to continuously send signal from your microcontroller, it's completely free running,

Features

• 5V voltage supply
• 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
• Reverse polarity protection on the terminal block input

 PCA968 Servo Driver tutorial by adafruit