Servo Motor Sweep Using Arduino

Introduction

Servo motors are commonly used in robotics and automation projects because they can rotate to a specific angle with high accuracy. In this project, we will make a servo motor rotate automatically from 0° to 180° and then back from 180° to 0° continuously using Arduino. This motion is called a servo sweep.

This project helps beginners understand:

Servo motor control
For loop operation
PWM output from Arduino

Components Required

Arduino Uno
Servo motor (SG90 or similar)
Capacitor (100 µF)
Jumper wires
Breadboard
USB cable

Circuit and Connections

Arduino Servo Motor Sweep Circuit Diagram

Servo Motor Wiring

Red wire → 5V
Brown/Black wire → GND
Yellow/Orange wire → Digital pin 9

⚠️ For large servos, use an external 5V power supply and connect common ground.

Working Principle

The Arduino sends control pulses to the servo motor through a digital pin. The servo motor rotates to a particular angle depending on the pulse width. In this program, Arduino gradually increases the angle from 0° to 180° in steps of 1 degree, waits briefly, and then decreases the angle back to 0°. This creates a smooth sweeping motion.

Arduino Code


#include <Servo.h>

Servo myservo;  // create servo object to control a servo

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) { 
    myservo.write(pos);              
    delay(15);                       
  }

  for (pos = 180; pos >= 0; pos -= 1) { 
    myservo.write(pos);              
    delay(15);                       
  }
}

Code Explanation

1. Include Servo Library


#include <Servo.h>

This library allows Arduino to control servo motors easily.

2. Create Servo Object


Servo myservo;

Creates a servo object named myservo.

3. Variable Declaration


int pos = 0;

Stores the current position (angle) of the servo motor.

4. Setup Function


myservo.attach(9);

Connects the servo motor signal wire to digital pin 9.

5. Loop Function


for (pos = 0; pos <= 180; pos += 1)

Moves the servo from 0° to 180° in steps of 1 degree.


myservo.write(pos);

Rotates the servo to the specified angle.


delay(15);

Gives time for the servo to reach the position.


for (pos = 180; pos >= 0; pos -= 1)

Moves the servo back from 180° to 0°.

Output

Servo motor rotates smoothly from 0° to 180°.
Then it rotates back from 180° to 0°.
This motion repeats continuously.

Applications

Radar scanning models
Robotic arm movement
Automatic gate systems
Camera pan systems
Educational demonstrations

Conclusion

This project demonstrates how to control a servo motor using Arduino and make it rotate automatically between two angles. It is a simple and effective project for beginners to understand servo control and looping concepts.

Safety Tips

Do not stall the servo at end positions
Use external power for high torque servos
Always connect common ground

Basic Electronics for Beginners

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