Meet the Servo — Angle Control Basics

By the end of this mission, you will be able to:

• Explain what a servo motor is and how it differs from other motors

• Describe how a servo uses a signal to determine its angle

• Wire a servo motor to the ESP32 correctly

• Move a servo between two angles using code

Robot arms, camera gimbals, and RC car steering all point precisely thanks to one component: the servo motor. In this lesson, you'll wire one up and move it to exact angles using nothing but code.

Robo says: “A servo doesn't just spin — it points. Give it an angle, and it goes there and holds still. Let's wire one up.”

A servo motor moves to and holds a specific angle — typically between 0° and 180° — instead of spinning continuously like a regular motor.

Internally, a servo reads a signal on its signal wire, and the width of that signal tells it exactly which angle to move to. The Servo.h library handles generating this signal for you: myServo.attach(13) tells your code which pin the servo's signal wire is connected to, and myServo.write(angle) sets the target angle.

Servos often need more current than the ESP32's onboard pins can reliably supply, especially under load. An external 5V power supply is recommended to avoid brownouts or unexpected resets.

Move the servo between 0° and 90°.

#include <Servo.h>
Servo myServo;
void setup() {
myServo.attach(13); // signal pin
}
void loop() {
myServo.write(0);
delay(1000);
myServo.write(90);
delay(1000);
}

🔧 Try It Yourself

Try writing a few different angle values and watch how the servo moves, then write down what you tried:

Example: myServo.write(45) moved the servo about a quarter of the way through its range.

• A small angle (like 20)

• A middle angle (like 90)

• A large angle (like 170)

🤔 Discuss With a Partner or Write Your Answer

Why do you think a servo needs both a signal wire AND a separate power connection, instead of getting everything from one wire like an LED does?

1. A servo motor moves to and holds a specific ________ instead of spinning continuously.

2. The ________() function tells the code which pin the servo's signal wire is connected to.

3. The ________() function sets the angle a servo should move to.

4. Servos often need an external ________ supply because they can draw more current than the ESP32 alone can provide.

Draw a line (or write the matching letter in the blank) to connect each word to its meaning.

• I can explain what a servo motor is and how it differs from other motors

• I can describe how a servo uses a signal to determine its angle

• I can wire a servo motor to the ESP32 correctly

• I can move a servo between two angles using code

Question 1: What does a servo motor do that a regular motor doesn't?

🔍 Reveal answer (drag-select the blank space): B

Question 2: What does myServo.write(90) do?

🔍 Reveal answer (drag-select the blank space): B

Question 3: Why is external power often recommended for servo projects?

🔍 Reveal answer (drag-select the blank space): B

🏆 Level Up

Can you make the servo move to three different angles, pausing at each one?

Name one real device that uses a servo motor (think robot arms, RC cars, or camera equipment), and explain what job it does.

🤖 Robo Says

Your servo just made its first move! Next up: Lesson 2 — you'll turn that instant jump into smooth, sweeping motion.