How to Control Servo Motor in Arduino: Simple Guide

To control a servo motor in Arduino, use the Servo library to attach the servo to a pin and set its angle with write(). This lets you move the servo arm to any position between 0 and 180 degrees easily.

Syntax

The basic syntax to control a servo motor in Arduino involves including the Servo library, creating a Servo object, attaching it to a pin, and then setting the angle.

• #include <Servo.h>: Adds the Servo library.
• Servo servo;: Creates a servo object.
• servo.attach(pin);: Connects the servo to a digital pin.
• servo.write(angle);: Moves the servo to the specified angle (0-180).

arduino

#include <Servo.h>

Servo servo;

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

void loop() {
  servo.write(90); // Move servo to 90 degrees
  delay(1000);    // Wait 1 second
}

Example

This example moves the servo motor from 0 to 180 degrees in steps of 10 degrees, then back to 0. It demonstrates smooth control of the servo angle.

arduino

#include <Servo.h>

Servo servo;

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

void loop() {
  for (int angle = 0; angle <= 180; angle += 10) {
    servo.write(angle);       // Move servo to angle
    delay(500);              // Wait half a second
  }
  for (int angle = 180; angle >= 0; angle -= 10) {
    servo.write(angle);       // Move servo back
    delay(500);              // Wait half a second
  }
}

Output

Servo motor arm moves smoothly from 0° to 180° and back to 0° in 10° steps with half-second pauses.

Common Pitfalls

Common mistakes when controlling servo motors include:

• Not including the Servo library, causing errors.
• Attaching the servo to a pin that does not support PWM (digital pins 2-13 usually work).
• Using servo.write() with angles outside 0-180 degrees.
• Not providing enough power to the servo, which can cause jitter or no movement.
• Calling servo.attach() repeatedly inside loop() instead of setup().

Wrong way:

void loop() {
  servo.attach(9); // Wrong: attach inside loop
  servo.write(90);
  delay(1000);
}

Right way:

void setup() {
  servo.attach(9); // Attach once in setup
}

void loop() {
  servo.write(90);
  delay(1000);
}

Quick Reference

Here is a quick cheat sheet for controlling a servo motor with Arduino:

Command	Description
#include	Include the Servo library
Servo servo;	Create a servo object
servo.attach(pin);	Attach servo to a digital pin
servo.write(angle);	Set servo position (0-180 degrees)
servo.detach();	Detach servo to stop sending signals

Key Takeaways

Use the Servo library to easily control servo motors in Arduino.

Attach the servo once in setup() to a PWM-capable pin.

Use servo.write(angle) with angles between 0 and 180 degrees.

Provide stable power to the servo to avoid jitter.

Avoid attaching the servo repeatedly inside the loop.