Push Button with ESP32 DOIT DevKit v1 – Step-by-Step Tutorial

Introduction

A Push Button is a simple input device used to control circuits. When pressed, it makes a connection between its terminals and sends a digital signal to the ESP32.

In this tutorial, we’ll use a Push Button connected to GPIO 5 of ESP32 DOIT DevKit v1. When the button is pressed, the onboard LED (GPIO 2) will turn ON, and when released, the LED will turn OFF.

Components Required

• ESP32 DOIT DevKit v1
• Push Button (normally open type)
• 10kΩ resistor (pull-down)
• Breadboard and jumper wires
• USB cable

Circuit Diagram

• Push Button one side → GPIO 5
• Push Button other side → 3.3V
• 10kΩ resistor between GPIO 5 and GND (acts as pull-down resistor)
• LED → GPIO 12

⚠️ Note: ESP32 has internal pull-up and pull-down resistors. For simplicity, we will use the internal pull-down in code (no external resistor required).

Arduino Code

// Push Button with ESP32 DOIT DevKit v1
// Button at GPIO 5, Onboard LED at GPIO 2

int buttonPin = 5;   // Push Button connected to GPIO 5
int ledPin = 12;      //  LED at GPIO 12
int buttonState = 0; // Variable to store button state

void setup() {
  pinMode(buttonPin, INPUT_PULLDOWN); // Use internal pull-down resistor
  pinMode(ledPin, OUTPUT);            // Set LED as output
}

void loop() {
  buttonState = digitalRead(buttonPin); // Read button input
  
  if (buttonState == HIGH) {
    digitalWrite(ledPin, HIGH); // Turn ON LED when button pressed
  } else {
    digitalWrite(ledPin, LOW);  // Turn OFF LED when button released
  }
}

Step-by-Step Code Explanation

1. Define Pins

int buttonPin = 5;
int ledPin = 12;

Assign GPIO 5 for button and GPIO 12 for onboard LED.

Setup Function

pinMode(buttonPin, INPUT_PULLDOWN);
pinMode(ledPin, OUTPUT);

• INPUT_PULLDOWN enables ESP32’s internal pull-down resistor.
• LED is set as an output.

Loop Function

buttonState = digitalRead(buttonPin);
if (buttonState == HIGH) { ... }

Reads the button state.

If pressed (HIGH), LED turns ON.

If not pressed (LOW), LED turns OFF.

Output

• When you press the push button, the ESP32’s onboard LED (GPIO 12) will light up.
• When you release the button, the LED will turn off.

Real-Life Applications

• User Inputs → switches in appliances.
• Reset Buttons → in microcontrollers/devices.
• Control Systems → manual ON/OFF switch for IoT devices.
• Game Controllers → button-based input actions.

Troubleshooting

Problem	Cause	Solution
LED not responding	Wrong GPIO wiring	Ensure button is connected to GPIO 5
LED always ON	No pull-down resistor	Use INPUT_PULLDOWN or external 10kΩ resistor
LED flickers randomly	Button bouncing	Use software debouncing (future tutorial)
Wrong LED	Using external LED without resistor	Add 220Ω resistor for external LED