Read a Push Button with ESP32

Understand the target result

Build a stable digital input circuit and detect pressed and released states. The expected result is: Serial Monitor reports reliable button states.

Prepare the board and parts

Disconnect the ESP32 from USB. Put the ESP32, breadboard, jumper wires, and the listed lesson parts in front of you. Straighten bent pins gently and never force a module into the breadboard.

Make each connection with power off

1. Place the push button across the breadboard center gap.
2. Connect one button side to GPIO 4.
3. Connect the opposite side to GND; the sketch enables the internal pull-up resistor.

Install any library and upload the code

No additional Arduino library is required for this starter sketch. Select your ESP32 board and serial port before clicking Upload.

const int BUTTON = 4;
void setup() { Serial.begin(115200); pinMode(BUTTON, INPUT_PULLUP); }
void loop() {
  bool pressed = digitalRead(BUTTON) == LOW;
  Serial.println(pressed ? "PRESSED" : "RELEASED");
  delay(100);
}

Power the circuit and observe

Connect USB power only after the wiring check. Open Serial Monitor at 115200 baud when the sketch prints data. Watch the circuit for at least 20 seconds and compare it with this expected behavior: Serial Monitor reports reliable button states.

Change one value and test again

Make one small change—such as a delay, threshold, brightness, or displayed message—then upload again. This confirms that you understand which part of the program controls the result.