int ObstaclePin=A0;
int hasobstracle=LOW;

void setup() {
  pinMode(ObstaclePin, INPUT);
  Serial.begin(9600);
}

void loop() {
  hasobstracle=digitalRead(ObstaclePin);
  if(hasobstracle==HIGH)
  {
    Serial.println("stop something is ahead");
  }
 else
 {
Serial.println("path is clear");
 }
delay(2000);
}