Arduino Motor Control: DC, Stepper, Servo Complete Tutorial 2025

Introduction

Controlling motors is one of the most satisfying Arduino projects you can build. From spinning wheels on a robot to precise positioning in CNC machines, motor control is fundamental to robotics and automation.

Motor Types Comparison

DC Motor Control

DC motors are the simplest to use but require an H-bridge driver for bidirectional control and to handle the motor's current requirements.

Wiring with L298N Driver

// L298N Connections:
// ENA → Arduino Pin 9 (PWM for speed)
// IN1 → Arduino Pin 8 (direction)
// IN2 → Arduino Pin 7 (direction)
// Motor → OUT1 and OUT2
// 12V → External power supply
// GND → Arduino GND + Power supply GND

DC Motor Code

const int ENA = 9; // PWM speed control
const int IN1 = 8; // Direction pin 1
const int IN2 = 7; // Direction pin 2

void setup() {
 pinMode(ENA, OUTPUT);
 pinMode(IN1, OUTPUT);
 pinMode(IN2, OUTPUT);
}

void loop() {
 // Forward at 75% speed
 digitalWrite(IN1, HIGH);
 digitalWrite(IN2, LOW);
 analogWrite(ENA, 191); // 0-255
 delay(2000);
 
 // Reverse at 50% speed
 digitalWrite(IN1, LOW);
 digitalWrite(IN2, HIGH);
 analogWrite(ENA, 127);
 delay(2000);
 
 // Stop
 analogWrite(ENA, 0);
 delay(1000);
}

Stepper Motor Control

Stepper motors rotate in discrete steps, making them perfect for applications requiring precise positioning without feedback sensors.

Stepper Code with AccelStepper Library

#include <AccelStepper.h>

// A4988 driver pins
#define STEP_PIN 3
#define DIR_PIN 4

AccelStepper stepper(AccelStepper::DRIVER, STEP_PIN, DIR_PIN);

void setup() {
 stepper.setMaxSpeed(1000); // Steps per second
 stepper.setAcceleration(500); // Steps per second²
}

void loop() {
 // Move 200 steps (one full revolution for NEMA 17)
 stepper.moveTo(200);
 stepper.runToPosition();
 delay(500);
 
 // Return to start
 stepper.moveTo(0);
 stepper.runToPosition();
 delay(500);
}

Servo Motor Control

Servo motors have built-in position feedback and are controlled by PWM signals. They're the easiest motors to use with Arduino.

Servo Wiring

// Standard servo colors:
// Brown/Black → GND
// Red → 5V (or external 5-6V for larger servos)
// Orange/Yellow → Signal pin (PWM capable)

Servo Code

#include <Servo.h>

Servo myServo;
const int SERVO_PIN = 9;

void setup() {
 myServo.attach(SERVO_PIN);
}

void loop() {
 // Sweep from 0° to 180°
 for (int angle = 0; angle <= 180; angle += 5) {
 myServo.write(angle);
 delay(50);
 }
 
 // Sweep back
 for (int angle = 180; angle >= 0; angle -= 5) {
 myServo.write(angle);
 delay(50);
 }
}

Project Ideas

Troubleshooting