Introduction to Servos

Learn about servos and how to control them with the Raspberry Pi Pico and MicroPython.

By Kevin McAleer,    3 Minutes

Introduction

Welcome to Lesson 14 of the Raspberry Pi Pico with MicroPython - GPIO Mastery course. In this lesson, you will learn about servos and how to control them with the Raspberry Pi Pico and MicroPython. A servo is a small device that rotates to a specific position, making it ideal for controlling the movement of robots, drones, and other projects.

What is a Servo?

A servo is a small motor that can be controlled to rotate to a specific position. It has three wires: power, ground, and signal. The power wire provides power to the servo, while the ground wire provides a common ground for the servo and the Raspberry Pi Pico. The signal wire is used to send a pulse-width modulation (PWM) signal to the servo to control its position.

Connecting a Servo to Raspberry Pi Pico

To connect a servo to your Raspberry Pi Pico, you will need to connect its power wire to a 5V pin on the board, its ground wire to a GND pin on the board, and its signal wire to a PWM-enabled pin on the board. The signal wire is typically connected to pin GP18 on the Raspberry Pi Pico board.

Controlling a Servo with MicroPython

To control a servo with MicroPython, you will need to use the machine.PWM module to generate the PWM signal that controls the servo’s position. Here’s an example of how to control a servo with MicroPython:

from machine import Pin, PWM
import utime

# Initialize PWM on pin GP18 with a frequency of 50Hz
servo = PWM(Pin(18))
servo.freq(50)

# Set the servo to its minimum position
servo.duty_u16(2500)
utime.sleep(1)

# Set the servo to its maximum position
servo.duty_u16(12500)
utime.sleep(1)

# Set the servo to its middle position
servo.duty_u16(7500)
utime.sleep(1)

# Stop the PWM signal
servo.deinit()

In this example, we first initialize the PWM module on pin GP18 with a frequency of 50Hz. We then use the duty_u16 method to set the servo to its minimum, maximum, and middle positions. Finally, we stop the PWM signal using the deinit method.

Conclusion

In this lesson, you learned about servos and how to control them with the Raspberry Pi Pico and MicroPython. You also learned how to connect a servo to your board and how to write MicroPython code to control the servo’s position. You can use this knowledge to create a variety of projects that involve controlling the movement of robots, drones, and other projects using servos.