How to Control a Servo Motor with Arduino

Arduino, Electronics, Tutoriales

Servo motors are widely used in robotics, automation, and RC models because they can move to specific angles with precision. In this tutorial, you’ll learn how to connect a servo motor to an Arduino Uno and control its position with simple code.

📝 Required Components

1× Arduino Uno
1× Servo Motor (like SG90 or MG90S)
3× Male-to-male jumper wires
1× USB cable for Arduino

📖 How a Servo Motor Works

A servo motor is a small device that can rotate to a specific position and hold it there. It’s different from a regular DC motor, which spins continuously, because a servo moves to a precise angle based on the signal it receives. This makes it perfect for projects where you need accurate control, like moving the arm of a robot or steering a small vehicle.

The servo receives a control signal through a technique called PWM (Pulse Width Modulation). By changing the width of this signal, you tell the servo which angle to move to — typically between 0° and 180°. Inside, the servo has a small motor and a control circuit that interprets the signal and adjusts the position accordingly. Thanks to Arduino’s built-in Servo library, you don’t have to manage these signals manually: you simply tell the servo the angle you want, and the library does the rest.

📊 Wiring Connections

Servo Wire	Arduino Uno
Brown/Black (GND)	GND
Red (+5V)	5V
Orange/Yellow (Signal)	Digital pin 9

📦 Complete Arduino Code

We’ll use the built-in Servo library in Arduino IDE to make it easier to control the motor.

				
					#include <Servo.h>  // Include the Servo library

Servo ServoMotor;   // Create a Servo object

void setup() {
  ServoMotor.attach(9);  // Attach the servo to digital pin 9
}

void loop() {
  ServoMotor.write(0);    // Move to 0 degrees
  delay(1000);            // Wait 1 second

  ServoMotor.write(90);   // Move to 90 degrees
  delay(1000);            // Wait 1 second

  ServoMotor.write(180);  // Move to 180 degrees
  delay(1000);            // Wait 1 second
}

🔎 Breaking down the Code

Let’s review the code section by section:

Include the Servo library

Adds the Servo library, providing functions to control servo motors.

				
					#include <Servo.h>

Create a Servo object

				
					Servo ServoMotor;

Creates a Servo object named ServoMotor to control the motor.

Setup Function

				
					void setup() {
  ServoMotor.attach(9);
}

Links the servo motor control wire to digital pin 9.

Main Loop

				
					void loop() {
  ServoMotor.write(0);
  delay(1000);

  ServoMotor.write(90);
  delay(1000);

  ServoMotor.write(180);
  delay(1000);
}

Moves the servo to 0°, waits 1 second
Moves to 90°, waits 1 second
Moves to 180°, waits 1 second
Repeats forever

🚀 Uploading the Code to Arduino

Connect Arduino Uno to your computer via USB
Open the Arduino IDE
Copy and paste the code
Select Tools > Board > Arduino Uno
Select the correct Port
Click Upload (the right arrow button)

The servo motor should now move between 0°, 90°, and 180°.