Output Devices

For this week I worked with an output device by controlling a servo motor using an ESP32. The purpose of this assignment was to understand how a microcontroller can generate signals to move a physical actuator.

A servo motor is an ideal output device because it converts an electrical signal into a controlled mechanical movement. Unlike a standard DC motor, a servo can move to a specific angle, which makes it useful for robotic systems, mechanisms, doors, arms, and positioning systems.

In this exercise, the servo rotates in steps from 0° to 180° and then returns to its initial position.

A servo motor is an electromechanical device capable of moving to a specific angular position. It contains:

• A DC motor
• A gearbox
• A control circuit
• A potentiometer for position feedback

Servo motors are controlled through PWM signals. The width of the pulse determines the target angle of the shaft.

The servo motor was connected directly to the ESP32. Three wires are required:

GPIO 0 was used as the control pin for the servo signal.

The following code was used to control the servo:

#include <Arduino.h>
#include <ESP32Servo.h>

Servo Servo_1;

const int Pin_Servo_1 = 0;

void setup() {
  Servo_1.attach(Pin_Servo_1, 500, 2400);

  Servo_1.write(0);

  delay(1000);
}

void loop() {
  for (int Angle = 0; Angle <= 180; Angle += 45) {
    Servo_1.write(Angle);

    delay(1000); 
  }

  delay(1000);
  
  Servo_1.write(0);

  delay(1000);
}

Library Import

The code starts by including the required libraries:

• Arduino.h for standard Arduino functions.
• ESP32Servo.h to control servo motors with the ESP32.

Servo Object

A servo object named Servo_1 is created. This object is used later to send commands to the motor.

Pin Definition

The servo signal wire is connected to GPIO 0:

const int Pin_Servo_1 = 0;

Setup Function

Inside the setup function, the servo is attached to the selected pin:

Servo_1.attach(Pin_Servo_1, 500, 2400);

The values 500 and 2400 represent the minimum and maximum pulse width in microseconds. These values correspond approximately to 0° and 180°.

The servo is initialized at 0°:

Servo_1.write(0);

Loop Function

In the loop, the servo rotates from 0° to 180° in increments of 45°:

for (int Angle = 0; Angle <= 180; Angle += 45)

The movement sequence is:

• 0°
• 45°
• 90°
• 135°
• 180°

After reaching 180°, the servo returns to 0° and repeats the cycle.

The final result was a servo motor that moved repeatedly between different angles.

The motion was smooth and stable because the servo library generated the PWM signal automatically.

• Correct servo response
• Stable angular positions
• Repeatable movement cycle