The Crowtail-haptic Motor is using little DRV2605 motor driver from TI. It is designed specifically for controlling haptic motors - buzzers and vibration motors. Normally one would just turn those kinds of motors on and off, but this driver has the ability to have various effects when driving a vibe motor. For example, ramping the vibration level up and down, 'click' effects, different buzzer levels, or even having the vibration follow a musical/audio input.
Features
Specifically for controlling haptic motors- buzzers and vibration motors.
Follow a musical/audio input.
Support LRA (Linear Resonance Actuator) and ERM (Eccentric Rotating Mass).