When selecting a controller to drive a servo motor, which hardware feature is essential?

• A. Analog to Digital converter
• B. GPIO pins
• C. Pulse Width Modulation pin
• D. I2C pins

Answer: (B)

To drive a servo, you need to output a PWM signal on its control line. That means your controller must have a pin capable of producing a timed digital output. General-purpose I/O pins provide exactly that interface, and you can generate the required PWM either with dedicated PWM hardware that maps to a GPIO or by using a timer and toggling the pin in software. Without a pin capable of outputting the control pulse, the servo cannot respond.

The other features aren’t required for basic servo control. An Analog to Digital converter is for reading analog signals, not for sending the control pulse. I2C pins are used for a communication bus, which isn’t needed to position a single servo. A dedicated PWM pin is helpful, but it’s ultimately a capability of the GPIO system, and you can often achieve PWM through a timer connected to a GPIO.