Interfacing a Servo Motor with Arduino Nano

Introduction

Servo motors are widely used in robotics, automation, and DIY projects because they allow precise control of angular position. The Arduino Nano, being compact and versatile, is perfect for controlling servos in space-constrained projects. In this tutorial, we’ll learn how to connect and program a servo motor with the Arduino Nano

Components Required

• Arduino Nano (official or compatible board)

• Servo Motor (e.g., SG90 micro servo)
• Jumper wires
• USB cable (Mini-B) for programming

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Understanding the Servo Motor

Wires:

• Red → VCC (typically 5V)
• Brown/Black → GND
• Orange/Yellow → Signal (PWM input)

Working Principle: The servo motor rotates to a specific angle (0°–180°) based on the PWM signal sent from the Arduino

Circuit Connections

• Connect servo VCC (red) to 5V pin of Arduino Nano
• Connect servo GND (black/brown) to GND pin of Arduino Nano.
• Connect servo signal (orange/yellow) to digital pin D9 of Arduino Nano (you can choose other PWM-capable pins).
• If using a high-torque servo, power it with an external 5V supply and connect grounds together to avoid damaging the Nano

Installing the Servo Library

The Arduino IDE comes with a built-in Servo.h library.

• Open Arduino IDE → Go to Sketch > Include Library > Servo.
• This library simplifies sending PWM signals to the servo.

#include <Servo.h>

Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0;    // variable to store the servo position

void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}

void loop() {
  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(10);                       // waits 15 ms for the servo to reach the position
  }
  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(10);                       // waits 15 ms for the servo to reach the position
  }
}

Uploading the Code

• Connect Arduino Nano to your PC via USB.
• Select Tools > Board > Arduino Nano.

• Choose the correct Port.

• Click Upload.
• The servo should start sweeping back and forth.

Testing and Troubleshooting

• If the servo jitters, provide external power.
• Ensure common ground between Arduino and external supply.
• If the servo doesn’t move, check wiring and pin assignment.
• Use myServo.write(angle) to set specific angles (e.g., myServo.write(90) for center position).

Expanding the Project

• Control servo with a potentiometer for manual angle adjustment.
• Use ultrasonic sensors to make the servo respond to distance.
• Integrate with Bluetooth/Wi-Fi modules for remote control.

Conclusion

By following these steps, you’ve successfully interfaced a servo motor with an Arduino Nano. This forms the foundation for robotics arms, pan-tilt camera systems, and countless automation projects.