Buzzing the ESP32

Introduction

This tutorial is to get you started on your ESP32 and Arduino coding journey. We will start with a speaker to have a more hands on approach to join the bridge between hardware and software. The user should be able to change their code and quickly see that change be outputted based on a different sound that the speaker will produce. This is a great starter project to ease the user into the course for all skill levels. This is a easy way for the user to get accustomed to using the Arduino IDE and components everyone has seen but may have never used.

Learning Objectives

• Getting started with Arduino IDE coding
• Learn how to make a sound with a speaker

Background Information

We will be introducing coding based on Arduino IDE and how to turn a speaker on as well as change its sound based on frequency. This is a great way to prototype before getting started on designing a PCB. The speaker and led was chosen as these are products everyone has seen or heard of before, but may have never had the chance to work on those parts themselves.

Pro

• user controlled sound output
• connections to things used everyday

Con

• Could be difficult to scale up
• Components are fairly costly

Key concepts

• Basic Arduino code
• Setting up a circuit
• Output change based on user input

Getting Started

Required Downloads and Installations

Download the required arduino software, we will be doing the coding here

Required Components

Required Tools and Equipment

• A laptop with Arduino IDE downloaded
• Depending on the speaker, soldering may be needed
• Usb cable for connections

Part 01: Setting up the breadboard

Introduction

We will start this project by placing all of the components needed onto the breadboard and hooking it up to the correct terminals on the ESP32.

Objective

• Learn how to set up connections from the breadboard to ESP32
• Learn how to correctly orient a component based on the manufacturer’s datasheet

Background Information

Soldering a spring contact and a basic understanding of where to place the cables within the ESP32.

Components

• ESP32
• Speaker
• LED
• 220 ohm resistor
• jumper cables

Instructions

We will start by soldering one side of the wires onto the speaker.

Refer to the datasheet to see which contact is positive. In the case of the speaker I am using, the datasheet states that it is the left contact is the positive one.

Plug in the resistor and the LED onto the breadboard

Next using a cable, plug one side into any of the digital pins on the ESP32 and the other end onto the open side of the resistor

Then on the open side of the LED, we will use the GND pin from the ESP32 and plug that into the GND rail on the breadboard and hook it up into the LED

Place the open pins of the speaker into the breadboard, take note of where the positive contact is

Next using a cable, plug one side into any of the digital pins on the ESP32 and the other end into the positive contact of the speaker

Utilizing the GND rail, place the last cable from the rail into the negative contact of the speaker

Part 02: Setting up the code

Introduction

The next part of this project will utilize arduino IDE to get what we placed onto the breadboard to work

Objective

• Learn how to code in Arduino
• Set up components in Arduino

Background Information

Now that we have everything hooked up to the ESP32, next we will utilize the Arduino IDE to control all of the components that we hooked up.

Components

• ESP32
• USB cable

Instructions

Plug the USB cable into the ESP32 and connect it into your laptop/computer

Open up Arduino IDE

Take note of which digital pins were used as that will communicate which pin to be outputted.

const int buzzer = x; //buzzer to ESP32 pin x
const int LED = y; //LED to ESP32 pin y

Next we will use the variables declared as an output

void setup(){
   
  pinMode(buzzer, OUTPUT); // Set buzzer - pin x as an output
  pinMode(LED, OUTPUT); // Set LED - pin y as an output
}

Lastly, we will be putting everything into a loop, turning the LED on and off, and the speaker on and off as well

void   loop(){
 
  digitalWrite(LED, HIGH);  // Turns on the LED
  tone(buzzer, [FREQ]); // Send FREQ KHz sound signal...
  delay(1000);         // ...for 1 sec
  digitalWrite(LED, LOW);   //Turns off the LED
  noTone(buzzer);     // Stop sound...
  delay(1000);         // ...for 1sec
  
}

Example

Example code

const int buzzer = 35; //buzzer to ESP32 pin 35
const int LED = 34; //LED to ESP32 pin 34

void setup(){
   
  pinMode(buzzer, OUTPUT); // Set buzzer - pin 35 as an output
  pinMode(LED, OUTPUT); // Set LED - pin 34 as an output
}

void loop(){
 
  digitalWrite(LED, HIGH);  // Turns on the LED
  tone(buzzer, 1000); // Send 1KHz sound signal...
  delay(1000);         // ...for 1 sec
  digitalWrite(LED, LOW);   //Turns off the LED
  noTone(buzzer);     // Stop sound...
  delay(1000);         // ...for 1sec
  
}

Final produce image

Analysis

Once the code has been ran, we can see that the led should light up in tandem with the speaker making a sound. We can see this is because there wasn’t a delay() between the LED turning on and the speaker turning on. There are many things that can be changed in this code, based on the value given for the frequency of the tone, the sound would change if the value were higher or lower, what if there were more tones added or what if there was a delay before the LED turning on and the speaker going off.

Additional Resources

Useful links

Speaker Documentation

USE a BUZZER MODULE (PIEZO SPEAKER) USING ARDUINO UNO