Servo motor control with PWM in Raspberry Pi - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does PWM stand for and why is it used to control servo motors?

PWM stands for Pulse Width Modulation. It controls servo motors by sending pulses of varying lengths to set the motor's angle.

beginner

How does changing the pulse width affect a servo motor's position?

Changing the pulse width changes the servo's shaft angle. Short pulses move it to one end, longer pulses move it to the other end.

beginner

Which Raspberry Pi library is commonly used for PWM control of servos?

The RPi.GPIO library is commonly used to generate PWM signals to control servo motors on Raspberry Pi.

intermediate

What is the typical PWM frequency used for controlling standard hobby servos?

The typical PWM frequency for hobby servos is about 50 Hz, meaning 20 milliseconds per pulse cycle.

beginner

Why is it important to clean up GPIO settings after controlling a servo on Raspberry Pi?

Cleaning up GPIO settings frees the pins and prevents conflicts or unexpected behavior when running other programs.

What does the pulse width in PWM control for a servo motor?

A The angle of the servo shaft

B The speed of the servo motor

C The voltage supplied to the servo

D The temperature of the servo

The pulse width controls the angle of the servo shaft by changing the length of the pulse sent.

What is the typical PWM frequency used to control a hobby servo motor?

A 100 Hz

B 1 kHz

C 10 Hz

D 50 Hz

Hobby servos usually use a PWM frequency of 50 Hz, which means pulses repeat every 20 milliseconds.

Which Raspberry Pi library is often used to generate PWM signals for servo control?

A RPi.GPIO

B Pandas

C Matplotlib

D Flask

RPi.GPIO is a common library to control GPIO pins and generate PWM signals on Raspberry Pi.

Why should you call GPIO.cleanup() after running a servo control program?

A To increase the servo speed

B To reset the GPIO pins and avoid conflicts

C To save power

D To change the PWM frequency

GPIO.cleanup() resets the pins so other programs can use them without issues.

If you want the servo to move to its maximum angle, what should you do with the PWM pulse width?

A Send no pulse

B Send the shortest pulse width

C Send the longest pulse width within the servo's range

D Send a pulse at 1000 Hz frequency

The longest pulse width corresponds to the servo's maximum angle position.

Explain how PWM controls the position of a servo motor on a Raspberry Pi.

Think about how changing the length of the pulse changes the servo's angle.

Describe the steps to safely control a servo motor using PWM on a Raspberry Pi.

Consider the full process from setup to cleanup.