What function do motor controllers serve on a robot?

Motor controllers play a crucial role in the functionality of a robot by sending control signals from the microcontroller to the motors. The microcontroller, which acts as the brain of the robot, issues commands based on the programming and input from various sensors. The motor controller receives these commands and translates them into actionable signals that dictate how fast or in what direction the motors should spin. This enables precise control over the robot's movement and responsiveness to its environment.

It's important to note that while motor controllers are essential for managing the interaction between the microcontroller and the motors, they do not directly power the mechanical components of the robot or manage data transmission between sensors. Instead, they serve as the intermediary that translates high-level commands into specific motor actions, which can include regulating movement speed and direction. Though regulating speed is an important function of motor controllers, the fundamental role they play is in sending control signals, making the option about sending signals the most comprehensive among the choices.