const int pirPin = 4;      // PIR output pin
int pirState = LOW;        // Previous state
int val = 0;               // Current state

void setup() {
  Serial.begin(115200);
  pinMode(pirPin, INPUT);
  Serial.println("PIR Sensor Test");
}

void loop() {
  val = digitalRead(pirPin);   // Read PIR output

  if (val == HIGH && pirState == LOW) {
    // Motion detected
    Serial.println("Motion detected!");
    pirState = HIGH;
    logPresence();             // Optional: log to SD card / cloud
  }
  else if (val == LOW && pirState == HIGH) {
    // Motion ended
    Serial.println("Motion ended");
    pirState = LOW;
  }

  delay(100); // small delay to avoid spamming
}

// Example log function (expand to SD card or cloud)
void logPresence() {
  unsigned long timestamp = millis(); // milliseconds since ESP32 started
  Serial.print("Timestamp: ");
  Serial.println(timestamp);
}