Smart Door Alarm – DIY

// Smart Door Alarm - ESP32
// Reed Switch + Buzzer + Warning LED

#define REED_PIN   27
#define BUZZER_PIN 26
#define LED_PIN    25

void setup() {
  pinMode(REED_PIN, INPUT_PULLUP);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);

  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(LED_PIN, LOW);

  Serial.begin(115200);
}

void loop() {

  int doorState = digitalRead(REED_PIN);

  // Door opened
  if (doorState == HIGH) {
    digitalWrite(BUZZER_PIN, HIGH);
    digitalWrite(LED_PIN, HIGH);

    Serial.println("WARNING: Door Open!");
  }

  // Door closed
  else {
    digitalWrite(BUZZER_PIN, LOW);
    digitalWrite(LED_PIN, LOW);

    Serial.println("Door Closed");
  }

  delay(100);
}