const int PIN_TO_SENSOR = 19; // GPIO19 pin connected to OUTPUT pin of sensor
int pinStateCurrent   = LOW;  // current state of pin
int pinStatePrevious  = LOW;  // previous state of pin
int led = 5;
void setup() {
  Serial.begin(9600);            // initialize serial
  pinMode(PIN_TO_SENSOR, INPUT); // set ESP32 pin to input mode to read value from OUTPUT pin of sensor
  pinMode(led, OUTPUT);
}

void loop() {
  pinStatePrevious = pinStateCurrent; // store old state
  pinStateCurrent = digitalRead(PIN_TO_SENSOR);   // read new state

  if (pinStatePrevious == LOW && pinStateCurrent == HIGH) {   // pin state change: LOW -> HIGH
    Serial.println("Motion detected!");
    // TODO: turn on alarm, light or activate a device ... here
    digitalWrite(led, HIGH);
  }
  else
  if (pinStatePrevious == HIGH && pinStateCurrent == LOW) {   // pin state change: HIGH -> LOW
    Serial.println("Motion stopped!");
    // TODO: turn off alarm, light or deactivate a device ... here
    digitalWrite(led, LOW);
  }
}