ESP32でボタンによるLED制御（押している間だけ点灯）

1// ─────────────────────────────────────────
2//   BlueGrays · bluegrays.com
3//   ESP32 LED Control with Push Button (Push)
4// ─────────────────────────────────────────
5// The LED stays on while the button is held down and turns off when it is
6// released. The button pin uses the internal pull-up (INPUT_PULLUP), so no
7// external resistor is needed.
8//
9// Pins:
10//   GPIO 5 -> Red LED (with a 220 ohm resistor)
11//   GPIO 4 -> Button (other leg to GND)
12
13const int LED_PIN = 5;      // LED output
14const int BUTTON_PIN = 4;   // Button input
15
16void setup() {
17  pinMode(LED_PIN, OUTPUT);
18  pinMode(BUTTON_PIN, INPUT_PULLUP);  // Reads HIGH when not pressed
19}
20
21void loop() {
22  // A pressed button pulls the pin to GND: LOW = pressed
23  if (digitalRead(BUTTON_PIN) == LOW) {
24    digitalWrite(LED_PIN, HIGH);
25  } else {
26    digitalWrite(LED_PIN, LOW);
27  }
28}
29