int onoff = 4;    // select the input pin for the potentiometer
int sens = 0;
int val = 0;

void setup() {
  Serial.begin(19200);
  pinMode(onoff, OUTPUT);  // declare the ledPin as an OUTPUT
}

void loop() {
    val = analogRead(sens);
    Serial.println(val);
    if (val>=200){
      digitalWrite(onoff, HIGH); 
      delay(50);
      digitalWrite(onoff, LOW);
    } 
    /*delay(4000);  
    digitalWrite(onoff, HIGH); 
    delay(50);
    digitalWrite(onoff, LOW);*/

}