ESP32 - Button Toggle LED

In a previous tutorial, We have learned how to turn on the LED if the button is pressed, and turn off LED if the button is released. In this tutorial, We are going to learn how to toggle LED each time button is pressed.

The tutorial includes two main parts:

Hardware Required

1×ESP-WROOM-32 Dev Module
1×Micro USB Cable
1×Button
1×LED
1×220 ohm resistor
1×Breadboard
4×Jumper Wires
Please note: These are affiliate links. If you buy the components through these links, We may get a commission at no extra cost to you. We appreciate it.

About LED and Button

If you do not have knowledge of LED and button (pinout, how they work, how to connect them to ESP32, how to program for them...), learn about them in the following tutorials:

Wiring Diagram

ESP32 Button LED Wiring Diagram

Image is developed using Fritzing. Click to enlarge image

ESP32 Code - Button Toggles LED Without Debouncing

/* * Created by esp32io.com * * This example code is in the public domain * * Tutorial page: https://esp32io.com/tutorials/esp32-button-toggle-led */ // constants won't change const int BUTTON_PIN = 7; // ESP32 pin connected to button's pin const int LED_PIN = 3; // ESP32 pin connected to LED's pin // variables will change: int ledState = LOW; // the current state of LED int lastButtonState; // the previous state of button int currentButtonState; // the current state of button void setup() { Serial.begin(9600); // initialize serial pinMode(BUTTON_PIN, INPUT_PULLUP); // set ESP32 pin to input pull-up mode pinMode(LED_PIN, OUTPUT); // set ESP32 pin to output mode currentButtonState = digitalRead(BUTTON_PIN); } void loop() { lastButtonState = currentButtonState; // save the last state currentButtonState = digitalRead(BUTTON_PIN); // read new state if(lastButtonState == HIGH && currentButtonState == LOW) { Serial.println("The button is pressed"); // toggle state of LED ledState = !ledState; // control LED arccoding to the toggled state digitalWrite(LED_PIN, ledState); } }

Quick Steps

  • If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE
  • Connect the ESP32 board to your PC via a micro USB cable
  • Open Arduino IDE, select the right ESP32 board and COM port
  • Copy the above code and paste it to Arduino IDE
  • Click Upload button on Arduino IDE to compile and upload code to ESP32 board
  • Keep pressing the button several seconds and then release it.
  • See the change of LED's state

Code Explanation

Read the line-by-line explanation in comment lines of code!

In the code, ledState = !ledState is equivalent to the following code:

if(ledState == LOW) ledState = HIGH; else ledState = LOW;

※ NOTE THAT:

In practice, the above code does not work correctly sometimes. To make it always work correctly, we need to debounce for the button. Debouncing for the button is not easy for beginners. Fortunately, thanks to the ezButton library, We can do it easily.

ESP32 Code - Button Toggles LED With Debouncing

Why do we need debouncing? ⇒ see ESP32 - Button Debounce tutorial

/* * Created by esp32io.com * * This example code is in the public domain * * Tutorial page: https://esp32io.com/tutorials/esp32-button-toggle-led */ #include <ezButton.h> /// constants won't change const int BUTTON_PIN = 7; // the number of the pushbutton pin const int LED_PIN = 3; // the number of the LED pin ezButton button(BUTTON_PIN); // create ezButton object that attach to pin 7; // variables will change: int ledState = LOW; // the current state of LED void setup() { Serial.begin(9600); // initialize serial pinMode(LED_PIN, OUTPUT); // set ESP32 pin to output mode button.setDebounceTime(50); // set debounce time to 50 milliseconds } void loop() { button.loop(); // MUST call the loop() function first if(button.isPressed()) { Serial.println("The button is pressed"); // toggle state of LED ledState = !ledState; // control LED arccoding to the toggleed sate digitalWrite(LED_PIN, ledState); } }

Quick Steps

  • If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE
  • Install ezButton library. See How To
  • Copy the above code and paste it to Arduino IDE
  • Click Upload button on Arduino IDE to compile and upload code to ESP32 board
  • Press button several times
  • See the change of LED's state

Video Tutorial

We are considering to make the video tutorials. If you think the video tutorials are essential, please subscribe to our YouTube channel to give us motivation for making the videos.

Button and LED on Commercial Products

Most electronic products have a reset button. Additionally, the button also keeps other functionalities in many products.

※ NOTE THAT:

Note that this tutorial is incomplete. We will post on our Facebook Page when the tutorial is complete. Like it to get updated.

※ NOTICES

  • We are AVAILABLE for HIRE. See how to hire us to do your project
  • If this tutorial is useful for you, please support us to make more tutorials.
  • We spent a lot of time and effort to create the content for this tutorial, please respect our work! Please do not copy the content to share on other websites. Howerver, please feel free to share the link of this tutorial anywhere