Buzzer with ESP32 DOIT DevKit v1 – Step-by-Step Tutorial

Introduction

A buzzer is a simple sound-producing device that can be controlled using a microcontroller. There are two types of buzzers:

• Active Buzzer → Produces sound when powered (no special frequency required).
• Passive Buzzer → Requires a frequency signal (PWM) to produce sound of different tones.

In this tutorial, we’ll use a buzzer connected to GPIO 4 of ESP32 DOIT DevKit v1 and make it beep using the Arduino IDE.

Components Required

• ESP32 DOIT DevKit v1
• Buzzer (active or passive)
• Breadboard and jumper wires
• USB cable

Circuit Diagram

• Buzzer + pin → GPIO 4
• Buzzer – pin → GND

⚠️ If using a passive buzzer, we will control the sound frequency using tone() function.

Arduino Code

// Active Buzzer with ESP32 DOIT DevKit v1
// Buzzer at GPIO 4

int buzzerPin = 4;

void setup() {
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  digitalWrite(buzzerPin, HIGH); // Turn buzzer ON
  delay(1000);                   // Wait 1 second
  digitalWrite(buzzerPin, LOW);  // Turn buzzer OFF
  delay(1000);                   // Wait 1 second
}

Step-by-Step Code Explanation

Define Pin

int buzzerPin = 4;

Assign GPIO 4 for the buzzer.

Setup Function

pinMode(buzzerPin, OUTPUT);

Configure buzzer pin as output.

Loop Function

digitalWrite(buzzerPin, HIGH);
delay(1000);
digitalWrite(buzzerPin, LOW);
delay(1000);

• Turns buzzer ON for 1 second.
• Turns buzzer OFF for 1 second.
• Repeats continuously.

Output

• With active buzzer: You’ll hear a continuous beep (ON/OFF every second).
• With passive buzzer: You’ll hear a 1kHz tone for 1 second, then silence for 1 second.

Real-Life Applications

• Alarms → fire alarms, smoke detectors.
• Doorbells → sound notification when pressed.
• Timers → reminder sounds in appliances.
• IoT Alerts → buzzers as warnings in smart systems.
• Games → sound effects.

Troubleshooting

Problem	Cause	Solution
No sound from buzzer	Wrong wiring	Connect + to GPIO 4 and – to GND
Weak sound	Low current from GPIO	Use a transistor driver circuit
Noise instead of tone	Passive buzzer used as active	Use tone() for passive buzzer
ESP32 reset/restart	Buzzer draws too much current	Use external power with transistor