#define IR_SENSOR 4
#define LED 13

int ldt=-1;
const int di=10000; //milisec
int cdt;

void setup() {
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(IR_SENSOR, INPUT);
  pinMode(LED, OUTPUT);
  digitalWrite(LED, LOW);
}

void loop() {
  int a=digitalRead(IR_SENSOR);
  if(a==1){
    Serial.println("Obstacle Detected");
    cdt=millis();
    if(ldt==-1){
      ldt=millis();
    } else if((cdt-ldt)>=di){
      digitalWrite(LED, HIGH);
    }
  } else{
    ldt=-1;
    digitalWrite(LED, LOW);
    Serial.println("-");
  }
  delay(1000);
}