Push Button

Components Needed

• 1x ESP32
• 1x USB Programming Cable
• 1x Double Width Breadboard
• 1x Push Button & Button Cap
• 1x 10kΩ Resistor (Brown-Black-Orange)
• 3x Male-to-Male Jumper Wires

Connections

Using the breadboards, connect the Push Button to the ESP32 as follows:

• Pin 1 → Not used
• Pin 2 (next to Pin 1) → ESP32 D21
• Pin 3 (diagonally across from Pin 2) → ESP32 3V3
• Pin 4 (next to Pin 3) → 10kΩ resistor → ESP32 GND

Code

Upload the following code onto the ESP32:

#define BUTTON_PIN 21  // Pin connected to the push button
#define LED_PIN 2      // Pin connected to an LED

void setup() {
  Serial.begin(115200);
  pinMode(BUTTON_PIN, INPUT);  // Set button pin as input
  pinMode(LED_PIN, OUTPUT);    // Set LED pin as output
}

void loop() {
  int buttonState = digitalRead(BUTTON_PIN);  // Read button state

  if (buttonState == HIGH) {
    digitalWrite(LED_PIN, HIGH);  // Turn LED on
    Serial.println("Button pressed - LED ON");
  } else {
    digitalWrite(LED_PIN, LOW);   // Turn LED off
    Serial.println("Button released - LED OFF");
  }

  delay(100);  // Small delay for stability
}

Explanation

The Push Button is a simple switch that completes a circuit when pressed. In this setup, the button connects the ESP32 D21 pin to 3V3 when pressed, and it pulls the pin to GND when not pressed. The 10kΩ resistor is used as a pull-down resistor to ensure that the input pin reads LOW when the button is not pressed.

In the code, the ESP32 reads the state of the button and performs an action based on whether the button is pressed or not. When the button is pressed, the ESP32 turns on an LED connected to another GPIO pin (for this example, the built-in LED on D2).

Results

Once the code is uploaded, the ESP32 will monitor the button state. When you press the button, the built-in LED will light up, and it will turn off when the button is released.

Try for Yourself

1. Modify the code to turn on and off the LED with different timing intervals (e.g., blink it on and off).
2. Use the button to trigger other actions, such as controlling a buzzer.