16 Channel Servo Driver HAT for Raspberry Pi is a servo driver HAT from which one can control up to 16 servo's simultaneously. If you're building a robot with a lot of moving parts, or if you need to monitor a lot of Servo motors with PWM yields, the microcontroller's limited PWM yields will be a big problem. The most important thing you can do to solve this problem is to obtain a 16-Channel 12-Bit PWM/Servo Driver.
With the 16-Channel 12-Bit PWM/Servo Driver, you can power 16 free-running Servo motors with only two pins. 62 breakouts can be fastened together to power up to 992 PWM outputs. It's a PWM driver with an implied clock that's powered by I2C.